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1. Bioinformatics Analysis Identified Five Widely Expressed Genes Associated with Prognosis in Sarcoma

Author

Tu B, Jia Y, and Qian J

Subjects
sarcoma, bio-informatics, prognostic values, differential expression gene, aspm, ccnb2, prc1, aurka, scm2, Medicine (General), R5-920
Abstract

Bizhi Tu,1,&ast; Yaya Jia,2,&ast; Jun Qian1 1Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China; 2Department of Pediatrics, The Shanxi Medical University, Taiyuan, Shanxi, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Jun Qian, Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, 230022, Anhui, People’s Republic of China, Tel +86-13955116514, Fax +86-551-62922025, Email qjpaper@sina.cnBackground: Human sarcomas (SARC) are a group of malignant tumors that originated from mesenchymal lineages with more than 60 subtypes. However, potential biomarkers for the diagnosis and prognosis of SARC remain to be investigated.Methods: We obtained three GSE raw matrix files (GSE39262, GSE21122, GSE48418) that related to various subtypes of sarcoma from the public GEO database and explored the widely differential expression genes in three obtained GSE files. Then common differential expression genes (CDGEs) were identified. We analyzed the correlation between the expression of the top five interacted genes of CDEGs and genome-wide differences, prognosis, genetic mutation, functional enrichment, immune infiltration, immune checkpoint, and marker genes’ expression of N6-methyladenosine (m6A) modification in SARC patients. Besides, a prognostic nomogram was constructed to predict the survival of SARC patients.Results: Among the three GSE files, 42 CDGEs were identified, and the top five interacted genes were ASPM, CCNB2, PRC1, AURKA, and SCM2. The expression levels of the five genes were higher in the SARC group than that in the normal group. The transcriptional level of CCNB2, PRC, and SCM2 was correlated to the worse survival of SARC. The constructed nomogram that combined CNB2, PRC1, and SCM2 showed a fairly good incredibility in predicting the survival of SARC (C-index: 0.711). Furthermore, the five genes were widely involved in immune infiltration, immune checkpoint, and m6A modification. In addition, we found a minor survival-related mutation rate (9%) of the five identified genes in SARC patients (p < 0.05).Conclusion: The results suggested the five identified genes widely participated in the prognosis, immune infiltration, immune checkpoint, and m6A modification of SARC patients. This study provided a theoretical basis for the research about the correlation between the level of five identified genes and sarcoma, but the further mechanism needs to be verified by experiments.Keywords: sarcoma, bioinformatics, prognostic values, differential expression gene, ASPM, CCNB2, PRC1, AURKA, SCM2

Published
2022

2. Insights into the Association Between QSER1 and M2 Macrophages and Remarkable Malignancy Characteristics in Hepatocellular Carcinoma

Author

Wu M, Shi Q, Duan SL, Ou-yang D, Chen P, Tu B, and Huang P

Subjects
hcc, qser1, prognosis, immune infiltration, Medicine (General), R5-920
Abstract

Min Wu,&ast; Qi-man Shi,&ast; Sai-Li Duan, Deng-jie Ou-yang, Pei Chen, Biao Tu, Peng Huang Department of General Surgery, Xiangya Hospital Central South University, Changsha, Hunan, 410008, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Peng Huang, Email xiangyahp@csu.edu.cnPurpose: Glutamine and serine rich 1 (QSER1), as a DNA methylation modulator, play a crucial role in transforming tumor cells. Previous studies have shown that QSER1 plays a role in regulating the progression of various malignancies and that QSER1 dysfunction is connected with precancerous lesions of hepatocellular carcinoma (HCC) as well as HCC prognosis. However, little is known about the detailed contribution of QSER1 in HCC.Patients and Methods: Various statistical methods such as Kaplan–Meier method, AUC analysis, GSEA, and immune-infiltration analysis were used to evaluate the relationship between QSER1 expression and clinical features, prognostic factors, and potential functional mechanisms of QSER1.Results: QSER1 expression was negatively correlated with clinicopathological features (clinical stage, pathological grade, TP53 mutation, lymph node metastasis) and clinical outcome (overall survival versus recurrence). Functional enrichment analysis further suggested that QSER1 is involved in multiple pathways related to DNA replication and tumor immunity. TIMER analysis indicated that high QSER1 expression was significantly associated with higher macrophage infiltration and poorer macrophage-related outcomes. In particular, QSER1 was significantly more associated with M2 macrophages than M1 macrophages.Conclusion: Overall, elevated QSER1 is a potential prognostic marker for HCC and is associated with immune infiltration in HCC.Keywords: HCC, QSER1, prognosis, immune infiltration

Published
2022

3. Prognostic Values of E2F1/2 Transcriptional Expressions in Chromophobe Renal Cell Carcinoma Patients: Evidence from Bioinformatics Analysis

Author

Hu D, Meng N, Lou X, Li Z, Teng Y, Tu B, Zou Y, and Wang F

Subjects
chromophobe renal cell carcinoma, e2fs, prognosis, ualcan, gepia, Medicine (General), R5-920
Abstract

Dingtao Hu,1,&ast; Nana Meng,2,&ast; Xiaoqi Lou,1 Zhen Li,3 Ying Teng,3 Bizhi Tu,4 Yanfeng Zou,3 Fang Wang1 1Department of Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China; 2Department of Quality Management Office, The Second Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China; 3Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Hefei, Anhui, People’s Republic of China; 4Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Fang WangDepartment of Oncology, The First Affiliated Hospital of Anhui Medical University, 218Jixi Road, Hefei, 230022, Anhui, People’s Republic of ChinaTel +86055162923615Fax +86055162923615Email wangfangahmu@163.comYanfeng ZouDepartment of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, No. 81, Meishan Road, Shushan District, Hefei, 230032, Anhui, People’s Republic of ChinaEmail zouyanfeng2015@163.comBackground: Numerous studies on the E2F transcription factors have led to increasing insights that E2Fs could be an important driver of the formation and progression of many human cancers. Little is known about the function of distinct E2Fs in chromophobe renal cell carcinoma (chRCC).Methods: We utilized the UALCAN, GEPIA, Cancer Genome Atlas (TCGA) database, cBioPortal, Metascape, STRING, Cytoscape, GeneMANIA, TIMER, TISIDB, GSCALite, and MEXPRESS databases to investigate the transcription level, genetic alteration, methylation, and biological function of E2Fs in chRCC patients, and its association with the occurrence, progress, prognosis, and immune cell infiltration in patients with chRCC.Results: We found that E2F1/2/4/7/8 were more expressed in chRCC tissues than in normal tissues, while the expression of E2F5/6 was lower in the former than in the latter, and the expression levels of E2F1/2/4/5/6//7/8 were also associated with the histological parameters of chRCC, including T-stage and N-stage. Higher expression of E2F1/2/7/8 was found to be significantly correlated with worse overall survival (OS) in chRCC patients. Cox regression and time-dependent ROC analysis further suggested that E2F1/2 could be the potential independent biomarkers for chRCC prognosis. Besides, a moderate mutation rate of E2Fs (34%) was noticed in chRCC, and the genetic mutations in E2Fs were associated with poor survival of chRCC patients. We noticed that the expression of E2Fs was statistically correlated with the immune cell infiltration in chRCC. Moreover, we also found that the expression of E2F1 was significantly correlated with tumor-infiltrating lymphocytes and immunomodulators, E2F7 expression was associated with MHC molecules, and the expression of E2F1/8 was correlated to their methylation levels.Conclusion: Our results provide novel insights for selecting the prognostic biomarkers for chRCC and suggest that E2F1/2 could act as potential prognostic biomarkers for the survival of chRCC patients. However, more in-depth experiments are required to identify the underlying mechanisms and verify the clinical value of E2F1/2 in the prognosis of chRCC.Keywords: chromophobe renal cell carcinoma, E2Fs, prognosis, UALCAN, GEPIA

Published
2021

4. Overexpression of SOX9 alleviates the progression of human osteoarthritis in vitro and in vivo

Author

Ouyang Y, Wang W, Tu B, Zhu Y, Fan C, and Li Y

Subjects
SOX9, osteoarthritis, collagen, inflammation, IL-1β, Therapeutics. Pharmacology, RM1-950
Abstract

Yuanming Ouyang,1,2 Wei Wang,1,2 Bing Tu,1,2 Yi Zhu,1,2 Cunyi Fan,1,2 Yanfeng Li1,21Department of Orthopedics, Shanghai Sixth People’s Hospital East Campus Shanghai University of Medicine and Health, Shanghai 201306, People’s Republic of China; 2Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai 200233, People’s Republic of ChinaPurpose: Recent findings have identified that SOX9 served as a key role during the pathogenesis of osteoarthritis (OA). This study aimed to investigate the mechanisms by which SOX9 regulated the formation of OA in vitro and in vivo.Materials and methods: The relative expressions of SOX9 in patients with OA and normal fracture of thighbone were analyzed by real-time-PCR. In vitro, IL-1β induced inflammatory response in human chondrocytes was used to evaluate the function of SOX9. The recombinant SOX9 lentivirus vector (Lenti-SOX9) was used to upregulate the expression of SOX9 in cells. ELISA was used to measure the concentration of tumornecrosis factor-α (TNF-α). The protein expressions of SOX9, matrixmetalloproteinase-13 (MMP13), Collagen II, Aggrecan and Smad3 were analyzed by Western blot. Cell proliferation and cell apoptosis were detected by CCK-8 assay and flow cytometry, respectively. In vivo, the effect of SOX9 on surgically induced OA mice was evaluated.Results: The gene level of SOX9 was remarkably downregulated in patients with OA compared with normal people, while the concentration of TNF-α was upregulated. In addition, IL-1β reduced the expressions of SOX9, Collagen II and Aggrecan and increased the level of MMP13 in chondrocytes. Moreover, Lenti-SOX9 notably inhibited IL-1β-induced growth inhibition and apoptosis in chondrocytes via increasing the expression of Smad3. Finally, Lenti-SOX9 markedly alleviated the symptoms of OA mice in vivo.Conclusion: Upregulation of SOX9 inhibited IL-1β-induced inflammatory response via increasing the level Smad3 in human chondrocytes and exhibited therapeutic effect on surgically induced OA mice in vivo. Therefore, SOX9 may serve as a potential target in the treatment of OA in the future.Keywords: SOX9, osteoarthritis, collagen, inflammation, IL-1β

Published
2019

5. Effect of continuous positive airway pressure on allergic rhinitis in patients with obstructive sleep apnea–hypopnea syndrome

Author

Yang QT, Li H, Wu WJ, Huang XK, Tu B, Ma YK, Deng HY, Li MJ, He HF, Li C, and Yang YQ

Subjects
Obstructive sleep apnea hypopnea syndrome, Continuous airway positive pressure, Allergic rhinitis, House dust mites, allergens, Therapeutics. Pharmacology, RM1-950
Abstract

Qintai Yang,1 Hui Li,2,* Weijun Wu,2,* Xuekun Huang,1 Bo Tu,2 Yukun Ma,2 Huiyi Deng,1 Meijiao Li,1 Hongfeng He,2 Can Li,2 Yongqi Yang2 1Department of Otorhinolaryngology – Head and Neck Surgery, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China; 2Department of Otorhinolaryngology – Head and Neck Surgery, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Background: The effect of continuous positive airway pressure (CPAP) on nasal symptoms in patients with obstructive sleep apnea–hypopnea syndrome (OSAHS) remains controversial. In addition, possible mechanism(s) remains unclear. Objective: To examine whether CPAP contributes to the onset and exacerbation of allergic rhinitis (AR) in OSAHS patients based on patient-reported changes in nasal symptoms with and without CPAP therapy and the detection of house dust mites (HDMs) in CPAP filters and household environments. Materials and methods: In a cohort of OSAHS patients, 350 patients who were undergoing CPAP therapy and 100 patients who declined CPAP therapy were retrospectively analyzed. These patients were contacted by telephone and asked to compare their nasal symptoms before and after CPAP therapy. HDMs in air conditioner and CPAP device filters and in household dust samples were detected using enzyme-linked immunosorbent assays. Results: The prevalence of AR was higher in the CPAP group vs the non-CPAP group (15.8% vs 7.0%, respectively; P = 0.025). The onset of AR among the OSAHS patients with no previous history of AR significantly increased within the first year of CPAP therapy compared with the control group (5.7% vs 0%, respectively; P = 0.031). Meanwhile, the patients with a history of AR were more likely to experience exacerbated rhinitis symptoms within the second year of treatment compared with the control group (7.5% vs 0%, respectively; P = 0.005). There was no significant difference in HDM concentrations between the CPAP and air conditioner filters, yet the concentrations in both the filters were higher than the concentrations in the bedroom dust samples (all P < 0.05). Conclusion: CPAP is associated with the onset and exacerbation of AR in OSAHS patients. Long-term exposure to high concentrations of HDM allergens may be a significant factor. Keywords: obstructive sleep apnea–hypopnea syndrome, continuous positive airway pressure, allergic rhinitis, house dust mites, allergens

Published
2018

6. High-precision determination of $g$ factors and masses of $^{20}\text{Ne}^{9+}$ and $^{22}\text{Ne}^{9+}$

Author

Heiße, F., Door, M., Sailer, T., Filianin, P., Herkenhoff, J., König, C. M., Kromer, K., Lange, D., Morgner, J., Rischka, A., Schweiger, Ch., Tu., B., Novikov, Y. N., Eliseev, S., Sturm, S., and Blaum, K.

Subjects
Physics - Atomic Physics
Abstract

We present the measurements of individual bound electron $g$ factors of $^{20}\text{Ne}^{9+}$ and $^{22}\text{Ne}^{9+}$ on the relative level of $0.1\,\text{parts}$ per billion. The comparison with theory represents the most stringent test of bound-state QED in strong electric fields. A dedicated mass measurement results in $m\left(^{20}\text{Ne}\right)=19.992\,440\,168\,77\,(9)\,\text{u}$, which improves the current literature value by a factor of nineteen, disagrees by $4$ standard deviations and represents the most precisely measured mass value in atomic mass units. Together, these measurements yield an electron mass on the relative level of $0.1\,\text{ppb}$ with $m_{\text{e}}=5.485\,799\,090\,99\,(59) \times 10^{-4}\,\text{u}$ as well as a factor of eight improved $m\left(^{22}\text{Ne}\right)=21.991\,385\,098\,2\,(26)\,\text{u}$.

Published
2023

8. Stringent test of QED with hydrogenlike tin

Author

Morgner, J., Tu, B., König, C. M., Sailer, T., Heiße, F., Bekker, H., Sikora, B., Lyu, C., Yerokhin, V. A., Harman, Z., López-Urrutia, J. R. Crespo, Keitel, C. H., Sturm, S., and Blaum, K.

Subjects
Physics - Atomic Physics
Abstract

Inner-shell electrons naturally sense the electric field close to the nucleus, which can reach extreme values beyond $10^{15}\,\text{V}/\text{cm}$ for the innermost electrons. Especially in few-electron highly charged ions, the interaction with the electromagnetic fields can be accurately calculated within quantum electrodynamics (QED), rendering these ions good candidates to test the validity of QED in strong fields. Consequently, their Lamb shifts were intensively studied in the last decades. Another approach is the measurement of $g$ factors in highly charged ions. However, so far, either experimental accuracy or small field strength in low-$Z$ ions limited the stringency of these QED tests. Here, we report on our high-precision, high-field test of QED in hydrogenlike $^{118}$Sn$^{49+}$. The highly charged ions were produced with the Heidelberg-EBIT (electron beam ion trap) and injected into the ALPHATRAP Penning-trap setup, where the bound-electron $g$ factor was measured with a precision of 0.5 parts-per-billion. For comparison, we present state-of-the-art theory calculations, which together test the underlying QED to about $0.012\,\%$, yielding a stringent test in the strong-field regime. With this measurement, we challenge the best tests via the Lamb shift and, with anticipated advances in the $g$-factor theory, surpass them by more than an order of magnitude.

Published
2023

11. Bulk Properties of the System Formed in Au+Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Aschenauer, E. C., Ashraf, M. U., Atetalla, F. G., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We report systematic measurements of bulk properties of the system created in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC).The transverse momentum spectra of $\pi^{\pm}$, $K^{\pm}$ and $p(\bar{p})$ are studied at mid-rapidity ($|y| < 0.1$) for nine centrality intervals. The centrality, transverse momentum ($p_T$),and pseudorapidity ($\eta$) dependence of inclusive charged particle elliptic flow ($v_2$), and rapidity-odd charged particles directed flow ($v_{1}$) results near mid-rapidity are also presented. These measurements are compared with the published results from Au+Au collisions at other energies, and from Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV. The results at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV show similar behavior as established at other energies and fit well in the energy dependence trend. These results are important as the 14.5 GeV energy fills the gap in $\mu_B$, which is of the order of 100 MeV,between $\sqrt{s_{\mathrm{NN}}}$ =11.5 and 19.6 GeV. Comparisons of the data with UrQMD and AMPT models show poor agreement in general., Comment: 30 pages, 29 figures and 8 tables

Published
2019
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12. Strange hadron production in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 7.7, 11.5, 19.6, 27, and 39 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., Ji, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We present STAR measurements of strange hadron ($\mathrm{K}^{0}_{\mathrm S}$, $\Lambda$, $\overline{\Lambda}$, $\Xi^-$, $\overline{\Xi}^+$, $\Omega^-$, $\overline{\Omega}^+$, and $\phi$) production at mid-rapidity ($|y| < 0.5$) in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 7.7 - 39 GeV from the Beam Energy Scan Program at the Relativistic Heavy Ion Collider (RHIC). Transverse momentum spectra, averaged transverse mass, and the overall integrated yields of these strange hadrons are presented versus the centrality and collision energy. Antibaryon-to-baryon ratios ($\overline{\Lambda}$/$\Lambda$, $\overline{\Xi}^+$/$\Xi^-$, $\overline{\Omega}^+$/$\Omega^-$) are presented as well, and used to test a thermal statistical model and to extract the temperature normalized strangeness and baryon chemical potentials at hadronic freeze-out ($\mu_{B}/T_{\rm ch}$ and $\mu_{S}/T_{\rm ch}$) in central collisions. Strange baryon-to-pion ratios are compared to various model predictions in central collisions for all energies. The nuclear modification factors ($R_{\textrm{CP}}$) and antibaryon-to-meson ratios as a function of transverse momentum are presented for all collision energies. The $\mathrm{K}^{0}_{\mathrm S}$ $R_{\textrm{CP}}$ shows no suppression for $p_{\rm T}$ up to 3.5 $\mathrm{GeV} / c$ at energies of 7.7 and 11.5 GeV. The $\overline{\Lambda}$/$\mathrm{K}^{0}_{\mathrm S}$ ratio also shows baryon-to-meson enhancement at intermediate $p_{\rm T}$ ($\approx$2.5 $\mathrm{GeV} / c$) in central collisions at energies above 19.6 GeV. Both observations suggest that there is likely a change of the underlying strange quark dynamics at collision energies below 19.6 GeV., Comment: 26 pages, 29 figures, version accepted by Physical Review C

Published
2019
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13. Longitudinal double-spin asymmetry for inclusive jet and dijet production in $pp$ collisions at $\sqrt{s} = 510$ GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report the first measurement of the inclusive jet and the dijet longitudinal double-spin asymmetries, $A_{LL}$, at midrapidity in polarized $pp$ collisions at a center-of-mass energy $\sqrt{s} = 510$ GeV. The inclusive jet $A_{LL}$ measurement is sensitive to the gluon helicity distribution down to a gluon momentum fraction of $x\approx 0.015$, while the dijet measurements, separated into four jet-pair topologies, provide constraints on the $x$ dependence of the gluon polarization. Both results are consistent with previous measurements made at $\sqrt{s}= 200$ GeV in the overlapping kinematic region, $x > 0.05$, and show good agreement with predictions from recent next-to-leading order global analyses.

Published
2019
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14. $g$-factor of Boronlike Argon $^{40}\textrm{Ar}^{13+}$

Author

Arapoglou, I., Egl, A., Höcker, M., Sailer, T., Tu, B., Weigel, A., Wolf, R., Cakir, H., Yerokhin, V. A., Oreshkina, N. S., Agababaev, V. A., Volotka, A. V., Zinenko, D. V., Glazov, D. A., Harman, Z., Keitel, C. H., Sturm, S., and Blaum, K.

Subjects
Physics - Atomic Physics
Abstract

We have measured the ground-state $g$-factor of boronlike argon $^{40}\textrm{Ar}^{13+}$ with a fractional uncertainty of \SI{1.4e-9}{} with a single ion in the newly developed ALPHATRAP double Penning-trap setup. The here obtained value of $g=0.663\,648\,455\,32(93)$ is in agreement with our theoretical prediction of $0.663\,648\,12(58)$. The latter is obtained accounting for quantum electrodynamics, electron correlation, and nuclear effects within the state-of-the-art theoretical methods. Our experimental result distinguishes between existing predictions that are in disagreement, and lays the foundations for an independent determination of the fine-structure constant., Comment: 6 pages, 3 figures, 2 tables

Published
2019
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15. Measurement of inclusive $J/\psi$ suppression in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV through the dimuon channel at STAR

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Calderón~de~la~Barca~Sánchez, M., Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

$J/\psi$ suppression has long been considered a sensitive signature of the formation of the Quark-Gluon Plasma (QGP) in relativistic heavy-ion collisions. In this letter, we present the first measurement of inclusive $J/\psi$ production at mid-rapidity through the dimuon decay channel in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV with the STAR experiment. These measurements became possible after the installation of the Muon Telescope Detector was completed in 2014. The $J/\psi$ yields are measured in a wide transverse momentum ($p_{\rm{T}}$) range of 0.15 GeV/$c$ to 12 GeV/$c$ from central to peripheral collisions. They extend the kinematic reach of previous measurements at RHIC with improved precision. In the 0-10% most central collisions, the $J/\psi$ yield is suppressed by a factor of approximately 3 for $p_{\rm{T}}>5$ GeV/$c$ relative to that in p+p collisions scaled by the number of binary nucleon-nucleon collisions. The $J/\psi$ nuclear modification factor displays little dependence on $p_{\rm{T}}$ in all centrality bins. Model calculations can qualitatively describe the data, providing further evidence for the color-screening effect experienced by $J/\psi$ mesons in the QGP.

Published
2019
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16. Polarization of $\Lambda$ ($\bar{\Lambda}$) hyperons along the beam direction in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

The $\Lambda$ ($\bar{\Lambda}$) hyperon polarization along the beam direction has been measured for the first time in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. The polarization dependence on the hyperons' emission angle relative to the second-order event plane exhibits a sine modulation, indicating a quadrupole pattern of the vorticity component along the beam direction. The polarization is found to increase in more peripheral collisions, and shows no strong transverse momentum ($p_T$) dependence at $p_T>1$ GeV/$c$. The magnitude of the signal is about five times smaller than those predicted by hydrodynamic and multiphase transport models; the observed phase of the emission angle dependence is also opposite to these model predictions. In contrast, blast-wave model calculations reproduce the modulation phase measured in the data and capture the centrality and transverse momentum dependence of the signal once the model is required to reproduce the azimuthal dependence of the Gaussian source radii measured via the Hanbury-Brown and Twiss intensity interferometry technique., Comment: 8 pages, 4 figures, Submitted to Phys. Rev. Lett

Published
2019
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17. Observation of indirect ionization of W7+ in an electron-beam ion-trap plasma

Author

Lu, Q., He, J., Tian, H., Li, M., Yang, Y., Yao, K., Chen, C., Xiao, J., Li, J. G., Tu, B., and Zou, Y.

Subjects
Physics - Atomic Physics
Abstract

In this work, visible and extreme ultraviolet spectra of W7+ are measured using the high-temperature superconducting electron-beam ion trap (EBIT) at the Shanghai EBIT Laboratory under extremely low-energy conditions (lower than the nominal electron-beam energy of 130 eV). The relevant atomic structure is calculated using the flexible atomic code package based on the relativistic configuration interaction method. The GRASP2K code, in the framework of the multiconfiguration Dirac-Hartree-Fock method, is employed as well for calculating the wavelength of the M1 transition in the ground configuration of W7+. A line from the W7+ ions is observed at a little higher electron-beam energy than the ionization potential for W4+, making this line appear to be from W5+. A hypothesis for the charge-state evolution of W7+ is proposed based on our experimental and theoretical results; that is, the occurrence of W7+ ions results from indirect ionization caused by stepwise excitation between some metastable states of lower-charge-state W ions, at the nominal electron-beam energy of 59 eV.

Published
2019
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18. Measurements of the transverse-momentum-dependent cross sections of $J/\psi$ production at mid-rapidity in proton+proton collisions at $\sqrt{s} =$ 510 and 500 GeV with the STAR detector

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Tu, Z., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We present measurements of the differential cross sections of inclusive $J/\psi$ meson production as a function of transverse momentum ($p_{T}^{J/\psi}$) using the $\mu^{+}\mu^{-}$ and $e^{+}e^{-}$ decay channels in proton+proton collisions at center-of-mass energies of 510 and 500 GeV, respectively, recorded by the STAR detector at the Relativistic Heavy Ion Collider. The measurement from the $\mu^{+}\mu^{-}$ channel is for 0 $< p_{T}^{J/\psi} <$ 9 GeV/$c$ and rapidity range $|y^{J/\psi}| < $ 0.4, and that from the $e^{+}e^{-}$ channel is for 4 $< p_{T}^{J/\psi} <$ 20 GeV/$c$ and $|y^{J/\psi}| < $ 1.0. The $\psi(2S)$ to $J/\psi$ ratio is also measured for 4 $< p_{T}^{\rm meson} <$ 12 GeV/$c$ through the $e^{+}e^{-}$ decay channel. Model calculations, which incorporate different approaches toward the $J/\psi$ production mechanism, are compared with experimental results and show reasonable agreement within uncertainties.

Published
2019
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19. First observation of the directed flow of $D^{0}$ and $\overline{D^0}$ in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200~GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Calderón~de~la~Barca~Sánchez, M., Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Gopal, K., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jena, C., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract

We report the first measurement of rapidity-odd directed flow ($v_{1}$) for $D^{0}$ and $\overline{D^{0}}$ mesons at mid-rapidity ($|y| < 0.8$) in Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200\,GeV using the STAR detector at the Relativistic Heavy Ion Collider. In 10--80\% Au+Au collisions, the slope of the $v_{1}$ rapidity dependence ($dv_{1}/dy$), averaged over $D^{0}$ and $\overline{D^{0}}$ mesons, is -0.080 $\pm$ 0.017 (stat.) $\pm$ 0.016 (syst.) for transverse momentum $p_{\rm T}$ above 1.5~GeV/$c$. The absolute value of $D^0$-meson $dv_1/dy$ is about 25 times larger than that for charged kaons, with 3.4$\sigma$ significance. These data give a unique insight into the initial tilt of the produced matter, and offer constraints on the geometric and transport parameters of the hot QCD medium created in relativistic heavy-ion collisions., Comment: Submitted to Phys. Rev. Lett

Published
2019
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20. Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., JI, Y., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Yang, Z., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment, Nuclear Theory
Abstract

According to the CPT theorem, which states that the combined operation of charge conjugation, parity transformation and time reversal must be conserved, particles and their antiparticles should have the same mass and lifetime but opposite charge and magnetic moment. Here, we test CPT symmetry in a nucleus containing a strange quark, more specifically in the hypertriton. This hypernucleus is the lightest one yet discovered and consists of a proton, a neutron, and a $\Lambda$ hyperon. With data recorded by the STAR detector{\cite{TPC,HFT,TOF}} at the Relativistic Heavy Ion Collider, we measure the $\Lambda$ hyperon binding energy $B_{\Lambda}$ for the hypertriton, and find that it differs from the widely used value{\cite{B_1973}} and from predictions{\cite{2019_weak, 1995_weak, 2002_weak, 2014_weak}}, where the hypertriton is treated as a weakly bound system. Our results place stringent constraints on the hyperon-nucleon interaction{\cite{Hammer2002, STAR-antiH3L}}, and have implications for understanding neutron star interiors, where strange matter may be present{\cite{Chatterjee2016}}. A precise comparison of the masses of the hypertriton and the antihypertriton allows us to test CPT symmetry in a nucleus with strangeness for the first time, and we observe no deviation from the expected exact symmetry.

Published
2019
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21. Beam energy dependence of (anti-)deuteron production in Au+Au collisions at RHIC

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yu, N., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, Nuclear Theory
Abstract

We report the energy dependence of mid-rapidity (anti-)deuteron production in Au+Au collisions at $\sqrt{s_\text{NN}} =\ $7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV, measured by the STAR experiment at RHIC. The yield of deuterons is found to be well described by the thermal model. The collision energy, centrality, and transverse momentum dependence of the coalescence parameter $B_2$ are discussed. We find that the values of $B_2$ for anti-deuterons are systematically lower than those for deuterons, indicating that the correlation volume of anti-baryons is larger than that of baryons at $\sqrt{s_\text{NN}}$ from 19.6 to 39 GeV. In addition, values of $B_2$ are found to vary with collision energy and show a broad minimum around $\sqrt{s_\text{NN}}=\ $20 to 40 GeV, which might imply a change of the equation of state of the medium in these collisions., Comment: 12 pages, 13 figures, submitted to Phys. Rev. C

Published
2019
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22. Collision energy dependence of second-order off-diagonal and diagonal cumulants of net-charge, net-proton and net-kaon multiplicity distributions in Au+Au collisions

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, T., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pawlowska, D., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stefaniak, M., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We report the first measurements of a complete second-order cumulant matrix of net-charge, net-proton, and net-kaon multiplicity distributions for the first phase of the beam energy scan program at RHIC. This includes the centrality and, for the first time, the pseudorapidity window dependence of both diagonal and off-diagonal cumulants in Au+Au collisions at \sNN~= 7.7-200 GeV. Within the available acceptance of $|\eta|<0.5$, the cumulants grow linearly with the pseudorapidity window. Relative to the corresponding measurements in peripheral collisions, the ratio of off-diagonal over diagonal cumulants in central collisions indicates an excess correlation between net-charge and net-kaon, as well as between net-charge and net-proton. The strength of such excess correlation increases with the collision energy. The correlation between net-proton and net-kaon multiplicity distributions is observed to be negative at \sNN~= 200 GeV and change to positive at the lowest collision energy. Model calculations based on non-thermal (UrQMD) and thermal (HRG) production of hadrons cannot explain the data. These measurements will help map the QCD phase diagram, constrain hadron resonance gas model calculations, and provide new insights on the energy dependence of baryon-strangeness correlations. An erratum has been added to address the issue of self-correlation in the previously considered efficiency correction for off-diagonal cumulant measurement. Previously considered unidentified (net-)charge correlation results ($\sigma^{11}_{Q,p}$ and $\sigma^{11}_{Q,k})$ are now replaced with identified (net-)charge correlation ($\sigma^{11}_{Q^{PID},p}$ and $\sigma^{11}_{Q^{PID},k}$), Comment: Erratum: Phys. Rev. C 105, 029901 (10.1103/PhysRevC.105.029901)

Published
2019
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23. Azimuthal harmonics in small and large collision systems at RHIC top energies

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanád, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Khyzhniak, Y. V., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pintér, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M., and Zyzak, M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The first ($v_1^{\text{even}}$), second ($v_2$) and third ($v_3$) harmonic coefficients of the azimuthal particle distribution at mid-rapidity, are extracted for charged hadrons and studied as a function of transverse momentum ($p_T$) and mean charged particle multiplicity density $\langle \mathrm{N_{ch}} \rangle$ in U+U ($\roots =193$~GeV), Au+Au, Cu+Au, Cu+Cu, $d$+Au and $p$+Au collisions at $\roots = 200$~GeV with the STAR Detector. For the same $\langle \mathrm{N_{ch}} \rangle$, the $v_1^{\text{even}}$ and $v_3$ coefficients are observed to be independent of collision system, while $v_2$ exhibits such a scaling only when normalized by the initial-state eccentricity ($\varepsilon_2$). The data also show that $\ln(v_2/\varepsilon_2)$ scales linearly with $\langle \mathrm{N_{ch}} \rangle^{-1/3}$. These measurements provide insight into initial-geometry fluctuations and the role of viscous hydrodynamic attenuation on $v_n$ from small to large collision systems.

Published
2019
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24. Collision Energy Dependence of $p_{\rm t}$ Correlations in Au+Au Collisions at RHIC

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M. K., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We present two-particle $p_{\rm t}$ correlations as a function of event centrality for Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV at the Relativistic Heavy Ion Collider using the STAR detector. These results are compared to previous measurements from CERES at the Super Proton Synchrotron and from ALICE at the Large Hadron Collider. The data are compared with UrQMD model calculations and with a model based on a Boltzmann-Langevin approach incorporating effects from thermalization. The relative dynamical correlations for Au+Au collisions at $\sqrt{s_{\rm NN}}$ = 200 GeV show a power law dependence on the number of participant nucleons and agree with the results for Pb+Pb collisions at $\sqrt{s_{\rm NN}} = 2.76~ {\rm TeV}$ from ALICE. As the collision energy is lowered from $\sqrt{s_{\rm NN}}$ = 200 GeV to 7.7 GeV, the centrality dependence of the relative dynamical correlations departs from the power law behavior observed at the higher collision energies. In central collisions, the relative dynamical correlations increase with collision energy up to $\sqrt{s_{\rm NN}}$ = 200 GeV in contrast to previous measurements that showed little dependence on the collision energy., Comment: 7 pages, 6 figures

Published
2019
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25. Centrality and transverse momentum dependence of $D^0$-meson production at mid-rapidity in Au+Au collisions at ${\sqrt{s_{\rm NN}} = \rm{200\,GeV}}$

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Greiner, L., Grosnick, D., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Mustafa, M. K., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Qiu, H., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szelezniak, M., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M. K., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report a new measurement of $D^0$-meson production at mid-rapidity ($|y|$\,$<$\,1) in Au+Au collisions at ${\sqrt{s_{\rm NN}} = \rm{200\,GeV}}$ utilizing the Heavy Flavor Tracker, a high resolution silicon detector at the STAR experiment. Invariant yields of $D^0$-mesons with transverse momentum $p_{T}$ $\lesssim 9$\,GeV/$c$ are reported in various centrality bins (0--10\%, 10--20\%, 20--40\%, 40--60\% and 60--80\%). Blast-Wave thermal models are used to fit the $D^0$-meson $p_{T}$ spectra to study $D^0$ hadron kinetic freeze-out properties. The average radial flow velocity extracted from the fit is considerably smaller than that of light hadrons ($\pi,K$ and $p$), but comparable to that of hadrons containing multiple strange quarks ($\phi,\Xi^-$), indicating that $D^0$ mesons kinetically decouple from the system earlier than light hadrons. The calculated $D^0$ nuclear modification factors re-affirm that charm quarks suffer large amount of energy loss in the medium, similar to those of light quarks for $p_{T}$\,$>$\,4\,GeV/$c$ in central 0--10\% Au+Au collisions. At low $p_{T}$, the nuclear modification factors show a characteristic structure qualitatively consistent with the expectation from model predictions that charm quarks gain sizable collective motion during the medium evolution. The improved measurements are expected to offer new constraints to model calculations and help gain further insights into the hot and dense medium created in these collisions., Comment: 27 pages, 36 figures, submitted to PRC

Published
2018
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26. Measurement of the longitudinal spin asymmetries for weak boson production in proton-proton collisions at $\sqrt{s}$ = 510 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Feng, Y., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Kravtsov, P., Krueger, K., Mudiyanselage, N. Kulathunga, Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J., Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, H., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M. K., and Zyzak, M.

Subjects
High Energy Physics - Experiment
Abstract

We report new STAR measurements of the single-spin asymmetries $A_L$ for $W^+$ and $W^-$ bosons produced in polarized proton--proton collisions at $\sqrt{s}$ = 510 GeV as a function of the decay-positron and decay-electron pseudorapidity. The data were obtained in 2013 and correspond to an integrated luminosity of 250 pb$^{-1}$. The results are combined with previous results obtained with 86 pb$^{-1}$. A comparison with theoretical expectations based on polarized lepton-nucleon deep-inelastic scattering and prior polarized proton--proton data suggests a difference between the $\bar{u}$ and $\bar{d}$ quark helicity distributions for $0.05 < x < 0.25$. In addition, we report new results for the double-spin asymmetries $A_{LL}$ for $W^\pm$, as well as $A_L$ for $Z/\gamma^*$ production and subsequent decay into electron--positron pairs., Comment: 8 pages, 6 figures

Published
2018
Full Text
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27. Measurements of Dielectron Production in Au$+$Au Collisions at $\sqrt{s_{NN}}$= 27, 39, and 62.4 GeV from the STAR Experiment

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Edmonds, T., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kelsey, M., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, X., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, J., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, D., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., Zurek, M. K., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

We report systematic measurements of dielectron ($e^{\pm}e^{\pm}$) invariant-mass $M_{ee}$ spectra at mid-rapidity in Au+Au collisions at $\sqrt{s_{NN}}$ = 27, 39, and 62.4 GeV taken with the STAR detector at the Relativistic Heavy Ion Collider. For all energies studied, a significant excess yield of dielectrons is observed in the low-mass region (0.40$ < M_{ee} < 0.75$ MeV/$c^2$) compared to hadronic cocktail simulations at freeze-out. Models that include an in-medium broadening of the $\rho$-meson spectral function consistently describe the observed excess. In addition, we report acceptance-corrected dielectron-excess spectra for Au+Au collisions at mid-rapidity ($\left|y_{ee}\right|$ $<$ 1) in the 0$-$80% centrality bin for each collision energy. The integrated excess yields for $0.4 < M_{ee} < 0.75\ \textrm{GeV}/c^{2}$, normalized by the charged particle multiplicity at mid-rapidity, are compared with previously published measurements for Au+Au at $\sqrt{s_{NN}}$ = 19.6 and 200 GeV. The normalized excess yields in the low-mass region show no significant collision energy dependence. The data, however, are consistent with model calculations that demonstrate a modest energy dependence.

Published
2018

28. Erratum: Observation of $D^0$ meson nuclear modifications in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kocan, M., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Licenik, R., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Moravcova, Z., Morozov, D. A., Nasim, Md., Nayak, K., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, J., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Zbroszczyk, H., Zha, W., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

In this erratum we report changes on the $D^0$ $p_T$ spectra and nuclear modification factor ($R_{AA}$) in Au+Au collisions at $\sqrt{s_{_{\mathrm{NN}}}}$ = 200 GeV by fixing the errors in the efficiency and selection criteria that affected the Au+Au results. The p+p reference spectrum has changed as well and is updated with new fragmentation parameters., Comment: 5 pages, 3 figures, erratum for Phys. Rev. Lett. 113,142301 (2014)

Published
2018

29. Improved measurement of the longitudinal spin transfer to $\Lambda$ and $\bar \Lambda$ hyperons in polarized proton-proton collisions at $\sqrt s$ = 200 GeV

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Cendejas, R., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deng, J., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, J., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., and Zyzak, M.

Subjects
High Energy Physics - Experiment
Abstract

The longitudinal spin transfer $D_{LL}$ to $\Lambda$ and $\bar{\Lambda}$ hyperons produced in high-energy polarized proton--proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and anti-quarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of $D_{LL}$ from data obtained at a center-of-mass energy of $\sqrt{s}$ = 200 GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure-of-merit than prior results and cover $|\eta|<$ 1.2 in pseudo-rapidity with transverse momenta $p_T$ up to 6 GeV/c. In the forward scattering hemisphere at largest $p_T$, the longitudinal spin transfer is found to be $D_{LL}$ = -0.036 $\pm$ 0.048 (stat) $\pm$ 0.013(sys) for $\Lambda$ hyperons and $D_{LL}$ = 0.032 $\pm$ 0.043\,(stat) $\pm$ 0.013\,(sys) for $\bar{\Lambda}$ anti-hyperons. The dependences on $\eta$ and $p_T$ are presented and compared with model evaluations., Comment: 8 pages, 4 figures

Published
2018
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30. Transverse spin transfer to $\Lambda$ and $\bar{\Lambda}$ hyperons in polarized proton-proton collisions at $\sqrt{s}=200\,\mathrm{GeV}$

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Cebra, D., Chakaberia, I., Chaloupka, P., Chan, B. K., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Csanad, M., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Hong, Y., Horvat, S., Huang, B., Huang, H. Z., Huang, S. L., Huang, T., Huang, X., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Ju, X., Judd, E. G., Kabana, S., Kagamaster, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Elayavalli, R. Kunnawalkam, Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, C., Li, W., Li, X., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, H., Liu, P., Liu, Y., Liu, Z., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, L., Ma, R., Ma, Y. G., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pinter, R. L., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, F., Shen, W. Q., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singh, J, Singha, S., Smirnov, D., Smirnov, N., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X. M., Sun, X., Sun, Y., Surrow, B., Svirida, D. N., Szymanski, P., Tang, A. H., Tang, Z., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, F., Wang, G., Wang, P., Wang, Y., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, J., Xu, N., Xu, Q. H., Xu, Y. F., Xu, Z., Yang, C., Yang, Q., Yang, S., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J., Zhang, L., Zhang, S., Zhang, X. P., Zhang, Y., Zhang, Z., Zhao, J., Zhong, C., Zhou, C., Zhu, X., Zhu, Z., and Zyzak, M.

Subjects
High Energy Physics - Experiment
Abstract

The transverse spin transfer from polarized protons to $\Lambda$ and $\bar{\Lambda}$ hyperons is expected to provide sensitivity to the transversity distribution of the nucleon and to the transversely polarized fragmentation functions. We report the first measurement of the transverse spin transfer to $\Lambda$ and $\bar{\Lambda}$ along the polarization direction of the fragmenting quark, $D_\mathrm{TT}$, in transversely polarized proton-proton collisions at $\sqrt{s}=200\,\mathrm{GeV}$ with the STAR detector at RHIC. The data correspond to an integrated luminosity of $18\,\mathrm{pb}^{-1}$ and cover the pseudorapidity range $\left|\eta\right| < 1.2$ and transverse momenta $p_{\mathrm{T}}$ up to $8\,\mathrm{GeV}/c$. The dependence on $p_\mathrm{T}$ and $\eta$ are presented. The $D_\mathrm{TT}$ results are found to be comparable with a model prediction, and are also consistent with zero within uncertainties., Comment: 8 pages, 4 figures, version to appear in Physical Review D

Published
2018
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31. Low-$p_T$ $e^{+}e^{-}$ pair production in Au$+$Au collisions at $\sqrt{s_{NN}}$ = 200 GeV and U$+$U collisions at $\sqrt{s_{NN}}$ = 193 GeV at STAR

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Klein, S. R., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report first measurements of $e^{+}e^{-}$ pair production in the mass region 0.4 $

Published
2018
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32. Longitudinal Double-Spin Asymmetries for $\pi^{0}$s in the Forward Direction for 510 GeV Polarized $pp$ Collisions

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

The STAR Collaboration reports measurements of the longitudinal double-spin asymmetry, $A_{LL}$, for neutral pions produced at forward directions in polarized proton-proton collisions, at a center-of-mass energy of $510$ GeV. Results are given for transverse momenta in the range $2

Published
2018
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33. Longitudinal Double-Spin Asymmetries for Dijet Production at Intermediate Pseudorapidity in Polarized $pp$ Collisions at $\sqrt{s}$ = 200 GeV

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We present the first measurements of the longitudinal double-spin asymmetry $A_{LL}$ for dijets with at least one jet reconstructed within the pseudorapidity range $0.8 < \eta < 1.8$. The dijets were measured in polarized $pp$ collisions at a center-of-mass energy $\sqrt{s}$ = 200 GeV. Values for $A_{LL}$ are determined for several distinct event topologies, defined by the jet pseudorapidities, and span a range of parton momentum fraction $x$ down to $x \sim$ 0.01. The measured asymmetries are found to be consistent with the predictions of global analyses that incorporate the results of previous RHIC measurements. They will provide new constraints on $\Delta g(x)$ in this poorly constrained region when included in future global analyses.

Published
2018
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34. Global polarization of $\Lambda$ hyperons in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV

Author

Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Calderón~de~la~Barca~Sánchez, M., Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

Global polarization of $\Lambda$ hyperons has been measured to be of the order of a few tenths of a percent in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV, with no significant difference between $\Lambda$ and $\bar{\Lambda}$. These new results reveal the collision energy dependence of the global polarization together with the results previously observed at $\sqrt{s_{_{NN}}}$ = 7.7 -- 62.4 GeV and indicate noticeable vorticity of the medium created in non-central heavy-ion collisions at the highest RHIC collision energy. The signal is in rough quantitative agreement with the theoretical predictions from a hydrodynamic model and from the AMPT (A Multi-Phase Transport) model. The polarization is larger in more peripheral collisions, and depends weakly on the hyperon's transverse momentum and pseudorapidity $\eta^H$ within $|\eta^H|<1$. An indication of the polarization dependence on the event-by-event charge asymmetry is observed at the $2\sigma$ level, suggesting a possible contribution to the polarization from the axial current induced by the initial magnetic field., Comment: 11 pages, 8 figures, Accepted for publication in Phys. Rev. C

Published
2018
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35. $J/\psi$ production cross section and its dependence on charged-particle multiplicity in $p+p$ collisions at $\sqrt{s}$ = 200 GeV

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sanchez, M. Calderon de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We present a measurement of inclusive $J/\psi$ production at mid-rapidity ($|y|<1$) in $p+p$ collisions at a center-of-mass energy of $\sqrt{s}$ = 200 GeV with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The differential production cross section for $J/\psi$ as a function of transverse momentum ($p_T$) for $0

Published
2018

36. Beam energy dependence of rapidity-even dipolar flow in Au+Au collisions

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, AJ, Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

New measurements of directed flow for charged hadrons, characterized by the Fourier coefficient \vone, are presented for transverse momenta $\mathrm{p_T}$, and centrality intervals in Au+Au collisions recorded by the STAR experiment for the center-of-mass energy range $\mathrm{\sqrt{s_{_{NN}}}} = 7.7 - 200$ GeV. The measurements underscore the importance of momentum conservation and the characteristic dependencies on $\mathrm{\sqrt{s_{_{NN}}}}$, centrality and $\mathrm{p_T}$ are consistent with the expectations of geometric fluctuations generated in the initial stages of the collision, acting in concert with a hydrodynamic-like expansion. The centrality and $\mathrm{p_T}$ dependencies of $\mathrm{v^{even}_{1}}$, as well as an observed similarity between its excitation function and that for $\mathrm{v_3}$, could serve as constraints for initial-state models. The $\mathrm{v^{even}_{1}}$ excitation function could also provide an important supplement to the flow measurements employed for precision extraction of the temperature dependence of the specific shear viscosity., Comment: 8 pages, four figures, submitted for publication

Published
2018
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37. Practical considerations for measuring global spin alignment of vector mesons in relativistic heavy ion collisions

Author

Tang, A. H., Tu, B., and Zhou, C. S.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Global spin alignment of vector mesons is a sensitive probe of system vorticity and particle production mechanism in relativistic heavy ion collisions. The measurement of global spin alignment is gaining increasing interest and deserves careful considerations. In this paper, we lay out a few practical issues that need to be taken care of when measuring global spin alignment of vector mesons. They are, the correction for event plane resolution, reconciling measurements made with different event planes, the correction for the effect of finite acceptance in pseudorapidity, and the consideration for measuring the azimuthal angle dependence. Insights and methodologies offered in this paper will help experiments to measure the global spin alignment properly and accurately., Comment: 6 pages. 4 figures. Accepted version by PRC

Published
2018
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38. Correlation Measurements Between Flow Harmonics in Au+Au Collisions at RHIC

Author

STAR Collaboration, Adam, J., Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Atetalla, F., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Bassill, A. J., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, F-H., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, J. H., Chen, X., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fulek, L., Gagliardi, C. A., Galatyuk, T., Geurts, F., Gibson, A., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Holub, L., Horvat, S., Huang, X., Huang, B., Huang, S. L., Huang, H. Z., Huang, T., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Kikoła, D. P., Kim, C., Kinghorn, T. A., Kisel, I., Kisiel, A., Kochenda, L., Kosarzewski, L. K., Kraishan, A. F., Kramarik, L., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, S., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, X., Li, C., Li, W., Li, Y., Liang, Y., Lidrych, J., Lin, T., Lipiec, A., Lisa, M. A., Liu, F., Liu, P., Liu, H., Liu, Y., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, X., Luo, S., Ma, G. L., Ma, Y. G., Ma, L., Ma, R., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Matonoha, O., Mayes, D., Mazer, J. A., Meehan, K., Mei, J. C., Minaev, N. G., Mioduszewski, S., Mishra, D., Mohanty, B., Mondal, M. M., Mooney, I., Morozov, D. A., Nasim, Md., Negrete, J. D., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Oh, S., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Radhakrishnan, S. K., Ramachandran, S., Ray, R. L., Reed, R., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seck, F., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shen, F., Shi, S. S., Shou, Q. Y., Sichtermann, E. P., Siejka, S., Sikora, R., Simko, M., Singha, S., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, Y., Sun, X., Sun, X. M., Surrow, B., Svirida, D. N., Szymanski, P., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Tomkiel, C. A., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., Vanek, J., Vasiliev, A. N., Vassiliev, I., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, Y., Wang, F., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Z., Xu, J., Xu, Y. F., Xu, N., Yang, S., Yang, C., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, Z., Zhang, L., Zhang, Y., Zhang, X. P., Zhang, J., Zhang, S., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, Z., Zhu, X., and Zyzak, M.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Flow harmonics ($v_n$) in the Fourier expansion of the azimuthal distribution of particles are widely used to quantify the anisotropy in particle emission in high-energy heavy-ion collisions. The symmetric cumulants, $SC(m,n)$, are used to measure the correlations between different orders of flow harmonics. These correlations are used to constrain the initial conditions and the transport properties of the medium in theoretical models. In this Letter, we present the first measurements of the four-particle symmetric cumulants in Au+Au collisions at $\sqrt{s_{NN}}$ = 39 and 200 GeV from data collected by the STAR experiment at RHIC. We observe that $v_{2}$ and $v_{3}$ are anti-correlated in all centrality intervals with similar correlation strengths from 39 GeV Au+Au to 2.76 TeV Pb+Pb (measured by the ALICE experiment). The $v_{2}$-$v_{4}$ correlation seems to be stronger at 39 GeV than at higher collision energies. The initial-stage anti-correlations between second and third order eccentricities are sufficient to describe the measured correlations between $v_{2}$ and $v_{3}$. The best description of $v_{2}$-$v_{4}$ correlations at $\sqrt{s_{NN}}$ = 200 GeV is obtained with inclusion of the system's nonlinear response to initial eccentricities accompanied by the viscous effect with $\eta/s$ $>$ 0.08. Theoretical calculations using different initial conditions, equations of state and viscous coefficients need to be further explored to extract $\eta/s$ of the medium created at RHIC., Comment: 4 figures, Accepted for publication in Physics Letter B, and final version

Published
2018

39. Azimuthal anisotropy in Cu+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV

Author

STAR Collaboration, Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Bouchet, J., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, X., Chen, J. H., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deng, J., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Feng, Z., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fujita, J., Fulek, L., Gagliardi, C. A., Geurts, F., Gibson, A., Girard, M., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Horvat, S., Huang, X., Huang, H. Z., Huang, T., Huang, B., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Khan, Z., Kikoła, D. P., Kim, C., Kisel, I., Kisiel, A., Kochenda, L., Kocmanek, M., Kollegger, T., Kosarzewski, L. K., Kraishan, A. F., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, W., Li, C., Li, X., Li, Y., Lidrych, J., Lin, T., Lisa, M. A., Liu, F., Liu, P., Liu, Y., Liu, H., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, R., Ma, Y. G., Ma, L., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mayes, D., Meehan, K., Mei, J. C., Miller, Z. W., Minaev, N. G., Mioduszewski, S., Mishra, D., Mizuno, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Pandit, Y., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Poniatowska, K., Porter, J., Posik, M., Poskanzer, A. M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Ramachandran, S., Ray, R. L., Reed, R., Rehbein, M. J., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Roth, J. D., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Saur, M., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shi, S. S., Shi, Z., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singha, S., Skoby, M. J., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X., Sun, Y., Sun, X. M., Surrow, B., Svirida, D. N., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Tawfik, A., Thäder, J., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Trzeciak, B. A., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., van Nieuwenhuizen, G., Vasiliev, A. N., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, F., Wang, Y., Webb, G., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Y. F., Xu, J., Xu, N., Xu, Z., Yang, C., Yang, S., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J., Zhang, S., Zhang, L., Zhang, X. P., Zhang, Z., Zhang, Y., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, X., Zhu, Z., and Zyzak, M.

Subjects
Nuclear Experiment
Abstract

The azimuthal anisotropic flow of identified and unidentified charged particles has been systematically studied in Cu+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV for harmonics $n=$ 1-4 in the pseudorapidity range $|\eta|<1$. The directed flow in Cu+Au collisions is compared with the rapidity-odd and, for the first time, the rapidity-even components of charged particle directed flow in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200~GeV. The slope of the directed flow pseudorapidity dependence in Cu+Au collisions is found to be similar to that in Au+Au collisions, with the intercept shifted toward positive $\eta$ values, i.e., the Cu-going direction. The mean transverse momentum projected onto the spectator plane, $\langle p_x\rangle$, in Cu+Au collision also exhibits approximately linear dependence on $\eta$ with the intercept at about $\eta\approx-0.4$, closer to the rapidity of the Cu+Au system center-of-mass. The observed dependencies find natural explanation in a picture of the directed flow originating partly due the "tilted source" and partly due to the rapidity dependent asymmetry in the initial density distribution. Charge-dependence of the $\langle p_x\rangle$ was also observed in Cu+Au collisions, indicating an effect of the initial electric field created by charge difference of the spectator protons in two colliding nuclei. The rapidity-even component of directed flow in Au+Au collisions is close to that in Pb+Pb collisions at $\sqrt{s_{_{NN}}}$ = 2.76 TeV, indicating a similar magnitude of dipole-like fluctuations in the initial-state density distribution. Higher harmonic flow in Cu+Au collisions exhibits similar trends to those observed in Au+Au and Pb+Pb collisions and is qualitatively reproduced by a viscous hydrodynamic model and a multi-phase transport model. For all harmonics with $n\ge2$ we observe an approximate scaling of $v_n$ with the number of constituent quarks., Comment: 20 pages, 19 figures, Accepted for publication in Phys. Rev. C

Published
2017
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40. Transverse spin-dependent azimuthal correlations of charged pion pairs measured in p$^\uparrow$+p collisions at $\sqrt{s}$ = 500 GeV

Author

STAR Collaboration, Adamczyk, L., Adams, J. R., Adkins, J. K., Agakishiev, G., Aggarwal, M. M., Ahammed, Z., Ajitanand, N. N., Alekseev, I., Anderson, D. M., Aoyama, R., Aparin, A., Arkhipkin, D., Aschenauer, E. C., Ashraf, M. U., Attri, A., Averichev, G. S., Bai, X., Bairathi, V., Barish, K., Behera, A., Bellwied, R., Bhasin, A., Bhati, A. K., Bhattarai, P., Bielcik, J., Bielcikova, J., Bland, L. C., Bordyuzhin, I. G., Bouchet, J., Brandenburg, J. D., Brandin, A. V., Brown, D., Bryslawskyj, J., Bunzarov, I., Butterworth, J., Caines, H., Sánchez, M. Calderón de la Barca, Campbell, J. M., Cebra, D., Chakaberia, I., Chaloupka, P., Chang, Z., Chankova-Bunzarova, N., Chatterjee, A., Chattopadhyay, S., Chen, X., Chen, J. H., Cheng, J., Cherney, M., Christie, W., Contin, G., Crawford, H. J., Das, S., Dedovich, T. G., Deng, J., Deppner, I. M., Derevschikov, A. A., Didenko, L., Dilks, C., Dong, X., Drachenberg, J. L., Draper, J. E., Dunlop, J. C., Efimov, L. G., Elsey, N., Engelage, J., Eppley, G., Esha, R., Esumi, S., Evdokimov, O., Ewigleben, J., Eyser, O., Fatemi, R., Fazio, S., Federic, P., Federicova, P., Fedorisin, J., Feng, Z., Filip, P., Finch, E., Fisyak, Y., Flores, C. E., Fujita, J., Fulek, L., Gagliardi, C. A., Geurts, F., Gibson, A., Girard, M., Grosnick, D., Gunarathne, D. S., Guo, Y., Gupta, A., Guryn, W., Hamad, A. I., Hamed, A., Harlenderova, A., Harris, J. W., He, L., Heppelmann, S., Herrmann, N., Hirsch, A., Horvat, S., Huang, X., Huang, H. Z., Huang, T., Huang, B., Humanic, T. J., Huo, P., Igo, G., Jacobs, W. W., Jentsch, A., Jia, J., Jiang, K., Jowzaee, S., Judd, E. G., Kabana, S., Kalinkin, D., Kang, K., Kapukchyan, D., Kauder, K., Ke, H. W., Keane, D., Kechechyan, A., Khan, Z., Kikoła, D. P., Kim, C., Kisel, I., Kisiel, A., Kochenda, L., Kocmanek, M., Kollegger, T., Kosarzewski, L. K., Kraishan, A. F., Krauth, L., Kravtsov, P., Krueger, K., Kulathunga, N., Kumar, L., Kvapil, J., Kwasizur, J. H., Lacey, R., Landgraf, J. M., Landry, K. D., Lauret, J., Lebedev, A., Lednicky, R., Lee, J. H., Li, W., Li, C., Li, X., Li, Y., Lidrych, J., Lin, T., Lisa, M. A., Liu, F., Liu, P., Liu, Y., Liu, H., Ljubicic, T., Llope, W. J., Lomnitz, M., Longacre, R. S., Luo, S., Luo, X., Ma, G. L., Ma, R., Ma, Y. G., Ma, L., Magdy, N., Majka, R., Mallick, D., Margetis, S., Markert, C., Matis, H. S., Mayes, D., Meehan, K., Mei, J. C., Miller, Z. W., Minaev, N. G., Mioduszewski, S., Mishra, D., Mizuno, S., Mohanty, B., Mondal, M. M., Morozov, D. A., Mustafa, M. K., Nasim, Md., Nayak, T. K., Nelson, J. M., Nemes, D. B., Nie, M., Nigmatkulov, G., Niida, T., Nogach, L. V., Nonaka, T., Nurushev, S. B., Odyniec, G., Ogawa, A., Oh, K., Okorokov, V. A., Olvitt Jr., D., Page, B. S., Pak, R., Pandit, Y., Panebratsev, Y., Pawlik, B., Pei, H., Perkins, C., Pluta, J., Poniatowska, K., Porter, J., Posik, M., Pruthi, N. K., Przybycien, M., Putschke, J., Quintero, A., Ramachandran, S., Ray, R. L., Reed, R., Rehbein, M. J., Ritter, H. G., Roberts, J. B., Rogachevskiy, O. V., Romero, J. L., Roth, J. D., Ruan, L., Rusnak, J., Rusnakova, O., Sahoo, N. R., Sahu, P. K., Salur, S., Sandweiss, J., Saur, M., Schambach, J., Schmah, A. M., Schmidke, W. B., Schmitz, N., Schweid, B. R., Seger, J., Sergeeva, M., Seto, R., Seyboth, P., Shah, N., Shahaliev, E., Shanmuganathan, P. V., Shao, M., Shen, W. Q., Shi, S. S., Shi, Z., Shou, Q. Y., Sichtermann, E. P., Sikora, R., Simko, M., Singha, S., Skoby, M. J., Smirnov, N., Smirnov, D., Solyst, W., Sorensen, P., Spinka, H. M., Srivastava, B., Stanislaus, T. D. S., Stewart, D. J., Strikhanov, M., Stringfellow, B., Suaide, A. A. P., Sugiura, T., Sumbera, M., Summa, B., Sun, X., Sun, Y., Sun, X. M., Surrow, B., Svirida, D. N., Tang, Z., Tang, A. H., Taranenko, A., Tarnowsky, T., Tawfik, A., Thäder, J., Thomas, J. H., Timmins, A. R., Tlusty, D., Todoroki, T., Tokarev, M., Trentalange, S., Tribble, R. E., Tribedy, P., Tripathy, S. K., Trzeciak, B. A., Tsai, O. D., Tu, B., Ullrich, T., Underwood, D. G., Upsal, I., Van Buren, G., van Nieuwenhuizen, G., Vasiliev, A. N., Videbæk, F., Vokal, S., Voloshin, S. A., Vossen, A., Wang, G., Wang, F., Wang, Y., Webb, G., Webb, J. C., Wen, L., Westfall, G. D., Wieman, H., Wissink, S. W., Witt, R., Wu, Y., Xiao, Z. G., Xie, G., Xie, W., Xu, Q. H., Xu, Y. F., Xu, J., Xu, N., Xu, Z., Yang, C., Yang, S., Yang, Q., Yang, Y., Ye, Z., Yi, L., Yip, K., Yoo, I. -K., Yu, N., Zbroszczyk, H., Zha, W., Zhang, J. B., Zhang, J., Zhang, S., Zhang, L., Zhang, X. P., Zhang, Z., Zhang, Y., Zhao, J., Zhong, C., Zhou, C., Zhou, L., Zhu, X., Zhu, Z., and Zyzak, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

The transversity distribution, which describes transversely polarized quarks in transversely polarized nucleons, is a fundamental component of the spin structure of the nucleon, and is only loosely constrained by global fits to existing semi-inclusive deep inelastic scattering (SIDIS) data. In transversely polarized $p^\uparrow+p$ collisions it can be accessed using transverse polarization dependent fragmentation functions which give rise to azimuthal correlations between the polarization of the struck parton and the final state scalar mesons. This letter reports on spin dependent di-hadron correlations measured by the STAR experiment. The new dataset corresponds to 25 pb$^{-1}$ integrated luminosity of $p^\uparrow+p$ collisions at $\sqrt{s}=500$ GeV, an increase of more than a factor of ten compared to our previous measurement at $\sqrt{s}=200$ GeV. Non-zero asymmetries sensitive to transversity are observed at a $Q^2$ of several hundred GeV and are found to be consistent with the former measurement and a model calculation. %we observe consistent with the former measurement are observed.} We expect that these data will enable an extraction of transversity with comparable precision to current SIDIS datasets but at much higher momentum transfers where subleading effects are suppressed., Comment: 20 pages, 7 figures, 5 tables, submitted to PLB

Published
2017
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42. Dual Fano and Lorentzian line profile poperties of autoionizing states

Author

Tu, B., Xiao, J., Yao, K., Shen, Y., Yang, Y., Lu, D., Li, W. X., Qiu, M. L., Wang, X., Chen, C. Y., Fu, Y. Q., Wei, B., Zheng, C., Huang, L. Y., Hutton, R., and Zou, Y.

Subjects
Physics - Atomic Physics
Abstract

Ott et al. (Science (340, 716 (2013)) successfully transferred Fano profile into Lorentzian lineshape using an intense infrared laser, after excitation of autoionizing states in helium by attosecond XUV pulse. This is a very important step forward of quantum phase control. However, here we show experimentally that an autoionizing state can have both Fano and Lorentzian behavior naturally, depending on the process involved. This study utilized the inverse process of photon absorption ionization, i.e. electron ion recombination with photon emission, making sure the resonant autoionizing state is not perturbed by the laser fields. Our result implies that excitation of the state through different paths can lead to different Fano profiles for the same resonant state. This allows more options for the combination of laser fields and lead to more opportunities for quantum phase control. Our result also indicates the breakdown of the classical two step picture for dielectronic recombination., Comment: 13 pages, 4 figuers

Published
2015

43. Enhanced photocatalytic activity and ferromagnetic ordering in hydrogenated Zn1−xCoxO.

Author

Petrov, Dimitar N., Dang, N. T., Co, N. D., Tu, B. D., Lam, N. D., Quang, T. V., Nguyen, V. Q., Lee, J. H., Huy, B. T., Yang, D. S., Khan, D. T., and Phan, T. L.

Subjects
PHOTOCATALYSTS, BAND gaps, X-ray powder diffraction, ELECTRONIC structure, RIETVELD refinement, SILVER, IRRADIATION, MAGNETIC entropy
Abstract

Impacts of hydrogen annealing on crystallographic characterization, electronic structure, and optical, photocatalytic, and magnetic properties of polycrystalline Zn1−xCoxO (x = 0.01–0.06) samples have been considered. Structural analyses based on powder X-ray diffraction, Rietveld refinement, and Raman spectroscopy prove all materials having the P63mc wurtzite-type structure. The Co-doping and hydrogenation changed the concentration of Zn– and O–related defects whose energy levels occupy the band gap. This also enhanced photocatalytic performance of hydrogenated samples with x > 0.02. X-ray and UV–Vis absorption analyses indicate the substitution of Co2+ for Zn2+ in the wurtzite-type ZnO lattice, leading to irregularly changed the unit-cell parameters. While all the as-prepared samples are paramagnetic, the hydrogenated ones exhibit weak ferromagnetism. Ferromagnetic (FM) ordering increases when x increases, particularly for x ≥ 0.02. According to the results achieved from studying crystalline and electronic structures, we believe that oxygen-vacancies-mediated interactions between Co2+ ions and H–Co–H exchange dimers enhanced FM ordering in hydrogenated Zn1−xCoxO. Computational investigations have also indicated that the magnetization value of H–Zn1−xCoxO is influenced by the positioning of the H dopant, meaning that the couplings between Co and H play an essential role in establishing FM order in H–Zn1−xCoxO. [ABSTRACT FROM AUTHOR]

Published
2024
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44. Large-scale RCI calculation of energy levels in W9+

Author

Qu, F.H., primary, Li, B.L., additional, Tu, B., additional, Zhang, C.Y., additional, Liu, X., additional, Xie, Y.M., additional, Lu, Q., additional, Yan, C.L., additional, Fu, N., additional, Si, R., additional, Chen, C.Y., additional, Wei, B., additional, Zou, Y., additional, and Xiao, J., additional

Published
2023
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47. Process Design Kit and Initial Demonstration of Digital Metal-Embedded Chip Assembly for High Density IO Fan-Out Packaging

Author

Nadri, Souheil, primary, Tu, B-A. Clayton, additional, Herrault, Florian, additional, Sharifi, Hasan, additional, McCue, Jamin, additional, Khan, Abdullah, additional, Schwan, David, additional, Botticello, David, additional, Das, Sanjana, additional, Kuzmenko, Daniel, additional, Wong, Joel, additional, Phan, Vu, additional, Nguyen, Jason, additional, and Wilt, Courtney, additional

Published
2023
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50. Investigating the magnetic and magnetocaloric behaviors of LiSm(PO3)4

Author

Tran, T. A., primary, Petrov, Dimitar N., additional, Phan, T. L., additional, Tu, B. D., additional, Nhat, H. N., additional, Tran, H. C., additional, Weise, B., additional, Cwik, J., additional, Koshkid'ko, Yu S., additional, Manh, T. V., additional, Hoang, T. P., additional, and Dang, N. T., additional

Published
2023
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