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1. Systemic inflammatory markers and volume of enhancing tissue on post-contrast T1w MRI images in differentiating true tumor progression from pseudoprogression in high-grade glioma

Author

Camilla Satragno, Irene Schiavetti, Eugenia Cella, Federica Picichè, Laura Falcitano, Martina Resaz, Monica Truffelli, Stefano Caneva, Pietro Mattioli, Daniela Esposito, Alessio Ginulla, Claudio Scaffidi, Pietro Fiaschi, Alessandro D’Andrea, Andrea Bianconi, Gianluigi Zona, Laura Barletta, Luca Roccatagliata, Lucio Castellan, Silvia Morbelli, Matteo Bauckneht, Isabella Donegani, Paolo Nozza, Dario Arnaldi, Giulia Vidano, Flavio Gianelli, Salvina Barra, Elisa Bennicelli, and Liliana Belgioia

Subjects
High-grade glioma, Pseudoprogression, Systemic Immune-Inflammation Index, Neutrophil-Lymphocyte Ratio, Post-contrast T1-weighted volume, Volumetric analysis, Medical physics. Medical radiology. Nuclear medicine, R895-920, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Background: High-grade glioma (HGG) patients post-radiotherapy often face challenges distinguishing true tumor progression (TTP) from pseudoprogression (PsP). This study evaluates the effectiveness of systemic inflammatory markers and volume of enhancing tissue on post-contrast T1 weighted (T1WCE) MRI images for this differentiation within the first six months after treatment. Material and Methods: We conducted a retrospective analysis on a cohort of HGG patients from 2015 to 2021, categorized per WHO 2016 and 2021 criteria. We analyzed treatment responses using modified RANO criteria and conducted volumetry on T1WCE and T2W/FLAIR images.Blood parameters assessed included neutrophil/lymphocyte ratio (NLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI). We employed Chi-square, Fisher’s exact test, and Mann-Whitney U test for statistical analyses, using log-transformed predictors due to multicollinearity. A Cox regression analysis assessed the impact of PsP- and TTP-related factors on overall survival (OS). Results: The cohort consisted of 39 patients, where 16 exhibited PsP and 23 showed TTP. Univariate analysis revealed significantly higher NLR and SII in the TTP group [NLR: 4.1 vs 7.3, p = 0.002; SII 546.5 vs 890.5p = 0.009]. T1WCE volume distinctly differentiated PsP from TTP [2.2 vs 11.7, p

Published
2024
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2. Brain metastases: Comparing clinical radiological differences in patients with lung and breast cancers treated with surgery

Author

Daniele Armocida, Giuseppa Zancana, Andrea Bianconi, Fabio Cofano, Alessandro Pesce, Brandon Matteo Ascenzi, Paola Bini, Enrico Marchioni, Diego Garbossa, and Alessandro Frati

Subjects
Brain metastases, Lung cancer, NSCLC, Breast cancer, Brain tumor, Surgery, RD1-811, Neurology. Diseases of the nervous system, RC346-429
Abstract

Purpose: Brain metastases (BMs) most frequently originate from the primary tumors of the lung and breast. Survival in patients with BM can improve if they are detected early. No studies attempt to consider all potential surgical predictive factors together by including clinical, radiological variables for their recognition. Methods: The study aims to simultaneously analyze all clinical, radiologic, and surgical variables on a cohort of 314 patients with surgically-treated BMs to recognize the main features and differences between the two histotypes. Results: The two groups consisted of 179 BM patients from lung cancer (Group A) and 135 patients from breast cancer (Group B). Analysis showed that BMs from breast carcinoma are more likely to appear in younger patients, tend to occur in the infratentorial site and are frequently found in patients who have other metastases outside of the brain (46 %, p = 0.05), particularly in bones. On the other hand, BMs from lung cancer often occur simultaneously with primitive diagnosis, are more commonly cystic, and have a larger edema volume. However, no differences were found in the extent of resection, postoperative complications or the presence of decreased postoperative performance status. Conclusion: The data presented in this study reveal that while the two most prevalent forms of BM exhibit distinctions with respect to clinical onset, age, tumor location, presence of extra-cranial metastases, and lesion morphology from a strictly surgical standpoint, they are indistinguishable with regard to outcome, demonstrating comparable resection rates and a low risk of complications.

Published
2024
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3. Laser Interstitial Thermotherapy (LITT) in Recurrent Glioblastoma: What Window of Opportunity for This Treatment?

Author

Alberto Morello MD, Andrea Bianconi MD, Francesca Rizzo MD, Jacopo Bellomo MD, PhD, Anna Cristina Meyer MS, Diego Garbossa MD, PhD, Luca Regli MD, and Fabio Cofano MD

Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
Abstract

Laser Interstitial Thermotherapy is a minimally invasive treatment option in neurosurgery for intracranial tumors, including recurrent gliomas. The technique employs the thermal ablation of target tissue to achieve tumor control with real-time monitoring of the extent by magnetic resonance thermometry, allowing targeted thermal injury to the lesion. Laser Interstitial Thermotherapy has gained interest as a treatment option for recurrent gliomas due to its minimally invasive nature, shorter recovery times, ability to be used even in patients with numerous comorbidities, and potential to provide local tumor control. It can be used as a standalone treatment or combined with other therapies, such as chemotherapy or radiation therapy. We describe the most recent updates regarding several studies and case reports that have evaluated the efficacy and safety of Laser Interstitial Thermotherapy for recurrent gliomas. These studies have reported different outcomes, with some demonstrating promising results in terms of tumor control and patient survival, while others have shown mixed outcomes. The success of Laser Interstitial Thermotherapy depends on various factors, including tumor characteristics, patient selection, and the experience of the surgical team, but the future direction of treatment of recurrent gliomas will include a combined approach, comprising Laser Interstitial Thermotherapy, particularly in deep-seated brain regions. Well-designed prospective studies will be needed to establish with certainty the role of Laser Interstitial Thermotherapy in the treatment of recurrent glioma.

Published
2024
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4. Deep Learning for MRI Segmentation and Molecular Subtyping in Glioblastoma: Critical Aspects from an Emerging Field

Author

Marta Bonada, Luca Francesco Rossi, Giovanni Carone, Flavio Panico, Fabio Cofano, Pietro Fiaschi, Diego Garbossa, Francesco Di Meco, and Andrea Bianconi

Subjects
artificial intelligence, deep learning, magnetic resonance imaging, glioblastoma, segmentation, molecular data, Biology (General), QH301-705.5
Abstract

Deep learning (DL) has been applied to glioblastoma (GBM) magnetic resonance imaging (MRI) assessment for tumor segmentation and inference of molecular, diagnostic, and prognostic information. We comprehensively overviewed the currently available DL applications, critically examining the limitations that hinder their broader adoption in clinical practice and molecular research. Technical limitations to the routine application of DL include the qualitative heterogeneity of MRI, related to different machinery and protocols, and the absence of informative sequences, possibly compensated by artificial image synthesis. Moreover, taking advantage from the available benchmarks of MRI, algorithms should be trained on large amounts of data. Additionally, the segmentation of postoperative imaging should be further addressed to limit the inaccuracies previously observed for this task. Indeed, molecular information has been promisingly integrated in the most recent DL tools, providing useful prognostic and therapeutic information. Finally, ethical concerns should be carefully addressed and standardized to allow for data protection. DL has provided reliable results for GBM assessment concerning MRI analysis and segmentation, but the routine clinical application is still limited. The current limitations could be prospectively addressed, giving particular attention to data collection, introducing new technical advancements, and carefully regulating ethical issues.

Published
2024
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5. Deep learning-based algorithm for postoperative glioblastoma MRI segmentation: a promising new tool for tumor burden assessment

Author

Andrea Bianconi, Luca Francesco Rossi, Marta Bonada, Pietro Zeppa, Elsa Nico, Raffaele De Marco, Paola Lacroce, Fabio Cofano, Francesco Bruno, Giovanni Morana, Antonio Melcarne, Roberta Ruda, Luca Mainardi, Pietro Fiaschi, Diego Garbossa, and Lia Morra

Subjects
Glioma, Glioblastoma, Magnetic resonance imaging, Deep learning, Machine learning, Segmentation, Computer applications to medicine. Medical informatics, R858-859.7, Computer software, QA76.75-76.765
Abstract

Abstract Objective Clinical and surgical decisions for glioblastoma patients depend on a tumor imaging-based evaluation. Artificial Intelligence (AI) can be applied to magnetic resonance imaging (MRI) assessment to support clinical practice, surgery planning and prognostic predictions. In a real-world context, the current obstacles for AI are low-quality imaging and postoperative reliability. The aim of this study is to train an automatic algorithm for glioblastoma segmentation on a clinical MRI dataset and to obtain reliable results both pre- and post-operatively. Methods The dataset used for this study comprises 237 (71 preoperative and 166 postoperative) MRIs from 71 patients affected by a histologically confirmed Grade IV Glioma. The implemented U-Net architecture was trained by transfer learning to perform the segmentation task on postoperative MRIs. The training was carried out first on BraTS2021 dataset for preoperative segmentation. Performance is evaluated using DICE score (DS) and Hausdorff 95% (H95). Results In preoperative scenario, overall DS is 91.09 (± 0.60) and H95 is 8.35 (± 1.12), considering tumor core, enhancing tumor and whole tumor (ET and edema). In postoperative context, overall DS is 72.31 (± 2.88) and H95 is 23.43 (± 7.24), considering resection cavity (RC), gross tumor volume (GTV) and whole tumor (WT). Remarkably, the RC segmentation obtained a mean DS of 63.52 (± 8.90) in postoperative MRIs. Conclusions The performances achieved by the algorithm are consistent with previous literature for both pre-operative and post-operative glioblastoma’s MRI evaluation. Through the proposed algorithm, it is possible to reduce the impact of low-quality images and missing sequences.

Published
2023
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6. Assessing the Relationship between Surgical Timing and Postoperative Seizure Outcomes in Cavernoma-Related Epilepsy: A Single-Institution Retrospective Analysis of 63 Patients with a Review of the Literature

Author

Elsa Nico, Christopher O. Adereti, Ashia M. Hackett, Andrea Bianconi, Anant Naik, Adam T. Eberle, Pere J. Cifre Serra, Stefan W. Koester, Samuel L. Malnik, Brandon M. Fox, Joelle N. Hartke, Ethan A. Winkler, Joshua S. Catapano, and Michael T. Lawton

Subjects
antiepileptic drugs, cavernoma, cavernoma-related epilepsy, cavernous angioma, cavernous hemangioma, cavernous malformation, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Background: Patients with supratentorial cavernous malformations (SCMs) commonly present with seizures. First-line treatments for cavernoma-related epilepsy (CRE) include conservative management (antiepileptic drugs (AEDs)) and surgery. We compared seizure outcomes of CRE patients after early (≤6 months) vs. delayed (>6 months) surgery. Methods: We compared outcomes of CRE patients with SCMs surgically treated at our large-volume cerebrovascular center (1 January 2010–31 July 2020). Patients with 1 sporadic SCM and ≥1-year follow-up were included. Primary outcomes were International League Against Epilepsy (ILAE) class 1 seizure freedom and AED independence. Results: Of 63 CRE patients (26 women, 37 men; mean ± SD age, 36.1 ± 14.6 years), 48 (76%) vs. 15 (24%) underwent early (mean ± SD, 2.1 ± 1.7 months) vs. delayed (mean ± SD, 6.2 ± 7.1 years) surgery. Most (32 (67%)) with early surgery presented after 1 seizure; all with delayed surgery had ≥2 seizures. Seven (47%) with delayed surgery had drug-resistant epilepsy. At follow-up (mean ± SD, 5.4 ± 3.3 years), CRE patients with early surgery were more likely to have ILAE class 1 seizure freedom and AED independence than those with delayed surgery (92% (44/48) vs. 53% (8/15), p = 0.002; and 65% (31/48) vs. 33% (5/15), p = 0.03, respectively). Conclusions: Early CRE surgery demonstrated better seizure outcomes than delayed surgery. Multicenter prospective studies are needed to validate these findings.

Published
2024
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7. Effects of Levetiracetam and Lacosamide on survival and seizure control in IDH-wild type glioblastoma during temozolomide plus radiation adjuvant therapy

Author

Andrea Bianconi, Emanuele Koumantakis, Andrea Gatto, Pietro Zeppa, Ayoub Saaid, Elsa Nico, Francesco Bruno, Alessia Pellerino, Francesca Rizzo, Carola Vera Junemann, Antonio Melcarne, Diego Garbossa, Paola Dalmasso, and Fabio Cofano

Subjects
Anti-Seizure medication, Brain tumor related epilepsy, Epilepsy, Glioblastoma, Lacosamide, Levetiracetam, Neurology. Diseases of the nervous system, RC346-429
Abstract

Introduction: There are no clear indications for the best choice of anti-seizure medications to control brain tumor related epilepsy. In vitro studies have shown an antitumoral effect of Levetiracetam and Lacosamide on glioblastoma IDH-wild type. Research question: This study investigates whether the use of levetiracetam and/or lacosamide impacts survival rates. The secondary aim was to evaluate the efficacy of both ASMs in controlling seizures. Materials and methods: In this observational retrospective single-cohort study, patients underwent chemoradiation protocol after GBM surgery. They were grouped as follows: (1) use of levetiracetam, (2) use of lacosamide, (3) simultaneous use of levetiracetam and lacosamide, (4) no ASM usage. Survival curves were plotted using the Kaplan-Meier method coupled with a log-rank test for difference assesments. To evaluate the pharmacological efficacy of post-operative seizure control, a negative binomial regression was conducted. Results: The study included 272 patients, 174 of which underwent adjuvant chemoradiation treatment. Patients without ASM therapy had a non-significant longer median OS (compared to the other groups (log-rank = 0.37). The IRR of seizure relapse was 2.57 (p = 0.007) times higher in lacosamide users, and MGMT promoter methylation demonstrated a protective effect against postoperative seizure onset (p = 0.05), regardless of the aforementioned confounding factors. Discussion and conclusions: In patients diagnosed with GBM IDH-WT undergoing chemoradiation therapy, the use of levetiracetam or lacosamide for controlling BTRE does not seem to modify survival. Lacosamide users exhibited a higher IRR of postoperative seizures compared to levetiracetam users, and MGMT promoter methylation appears to be a protective factor.

Published
2024
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8. Secondary Beams at High-Intensity Electron Accelerator Facilities

Author

Marco Battaglieri, Andrea Bianconi, Mariangela Bondí, Raffaella De Vita, Antonino Fulci, Giulia Gosta, Stefano Grazzi, Hyon-Suk Jo, Changhui Lee, Giuseppe Mandaglio, Valerio Mascagna, Tetiana Nagorna, Alessandro Pilloni, Marco Spreafico, Luca J. Tagliapietra, Luca Venturelli, and Tommaso Vittorini

Subjects
intensity frontier, neutrino interaction, dark matter, BSM physics, muon beam, Physics, QC1-999, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The interaction of a high-current O(100 µA), medium energy O(10 GeV) electron beam with a thick target O(1m) produces an overwhelming shower of standard model particles in addition to hypothetical light dark matter particles. While most of the radiation (gamma, electron/positron) is contained in the thick target, deep penetrating particles (muons, neutrinos, and light dark matter particles) propagate over a long distance, producing high-intensity secondary beams. Using sophisticated Monte Carlo simulations based on FLUKA and GEANT4, we explored the characteristics of secondary muons and neutrinos and (hypothetical) dark scalar particles produced by the interaction of the Jefferson Lab 11 GeV intense electron beam with the experimental Hall-A beam dump. Considering the possible beam energy upgrade, this study was repeated for a 22 GeV CEBAF beam.

Published
2024
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14. Updates in Glioblastoma Immunotherapy: An Overview of the Current Clinical and Translational Scenario

Author

Andrea Bianconi, Giuseppe Palmieri, Gelsomina Aruta, Matteo Monticelli, Pietro Zeppa, Fulvio Tartara, Antonio Melcarne, Diego Garbossa, and Fabio Cofano

Subjects
glioma, glioblastoma, immunotherapy, peptide vaccines, CAR-T therapy, oncolytic virus, Biology (General), QH301-705.5
Abstract

Glioblastoma (GBM) is the most common and aggressive central nervous system tumor, requiring multimodal management. Due to its malignant behavior and infiltrative growth pattern, GBM is one of the most difficult tumors to treat and gross total resection is still considered to be the first crucial step. The deep understanding of GBM microenvironment and the possibility of manipulating the patient’s innate and adaptive immune system to fight the neoplasm represent the base of immunotherapeutic strategies that currently express the future for the fight against GBM. Despite the immunotherapeutic approach having been successfully adopted in several solid and haematologic neoplasms, immune resistance and the immunosuppressive environment make the use of these strategies challenging in GBM treatment. We describe the most recent updates regarding new therapeutic strategies that target the immune system, immune checkpoint inhibitors, chimeric antigen receptor T cell therapy, peptide and oncolytic vaccines, and the relevant mechanism of immune resistance. However, no significant results have yet been obtained in studies targeting single molecules/pathways. The future direction of GBM therapy will include a combined approach that, in contrast to the inescapable current treatment modality of maximal resection followed by chemo- and radiotherapy, may combine a multifaceted immunotherapy treatment with the dual goals of directly killing tumor cells and activating the innate and adaptive immune response.

Published
2023
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15. Radiofrequency Ablation in Vertebral Body Metastasis with and without Percutaneous Cement Augmentation: A Systematic Review Addressing the Need for SPINE Stability Evaluation

Author

Stefano Colonna, Andrea Bianconi, Fabio Cofano, Alessandro Prior, Giuseppe Di Perna, Giuseppe Palmieri, Gianluigi Zona, Diego Garbossa, and Pietro Fiaschi

Subjects
vertebral metastases, spine stability, radiofrequency ablation, thermal ablation, vertebroplasty, kyphoplasty, Medicine (General), R5-920
Abstract

Vertebral body metastases (VBM) are one of the most frequent sites of bone metastasis, and their adequate therapeutic management still represents an insidious challenge for both oncologists and surgeons. A possible alternative treatment for VBM is radiofrequency ablation (RFA), a percutaneous technique in which an alternating current is delivered to the tumor lesion producing local heating and consequent necrosis. However, RFA alone could alter the biomechanics and microanatomy of the vertebral body, thus increasing the risk of post-procedure vertebral fractures and spine instability, and indeed the aim of the present study is to investigate the effects of RFA on spine stability. A systematic review according to PRISMA-P guidelines was performed, and 17 papers were selected for the systematic review. The results show how RFA is an effective, safe, and feasible alternative to conventional radiotherapy for the treatment of VBM without indication for surgery, but spine stability is a major issue in this context. Although exerting undeniable benefits on pain control and local tumor recurrence, RFA alone increases the risk of spine instability and consequent vertebral body fractures and collapses. Concomitant safe and feasible therapeutic strategies such as percutaneous vertebroplasty and kyphoplasty have shown synergic positive effects on back pain and improvement in spine stability.

Published
2023
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16. Optical Channeling of Low Energy Antiprotons in Thin Crystal Targets

Author

Andrea Bianconi, Giovanni Costantini, Giulia Gosta, Marco Leali, Valerio Mascagna, Stefano Migliorati, and Luca Venturelli

Subjects
antiproton, channeling, thin targets, coherence, Mathematics, QA1-939
Abstract

A relevant aspect of the interactions between charged fermions and crystal targets is coherence, which can exist at both classical and quantum levels. In the case of antiprotons crossing crystal targets, there are theories and measurements of classical-level coherence effects, in particular, channeling effects. For the present study, we assume the existence of a low-energy regime where the electrostatic interactions between an antiproton and the crystal atoms lead to a local loss in the beam flux as their leading effect. We expect this assumption to be well-justified for antiproton (p¯) energies below 100 eV, with a progressive transition to a standard “Rutherford regime” in the energy range 100–1000 eV. Under these conditions, the target can be treated as an optical absorber with a periodical structure, which can be simplified by considering a multi-layer planar structure only. As in standard optics, wave absorption is accompanied by interference and diffraction. Assuming sub-nanometer ranges for the relevant parameters and a realistic angular spread for the antiproton beam, we find narrow-angle focusing effects that reproduce the classical channeling effect at a qualitative level. We also find that diffraction dominates over interference, although this may strongly depend on the target details.

Published
2023
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17. Elderly Gliobastoma Patients: The Impact of Surgery and Adjuvant Treatments on Survival: A Single Institution Experience

Author

Francesco Bruno, Alessia Pellerino, Edoardo Pronello, Rosa Palmiero, Luca Bertero, Cristina Mantovani, Andrea Bianconi, Antonio Melcarne, Diego Garbossa, and Roberta Rudà

Subjects
glioblastoma, elderly patients, extent of resection, gross-total resection, MGMTp methylation, adjuvant treatments, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Introduction. Elderly glioblastoma (GBM) patients often show limited response to treatment and poor outcome. Here, we provide a case series of elderly GBM patients from our Institution, in whom we assessed the clinical characteristics, feasibility of surgical resection, response to adjuvant treatments, and outcome, along with the impact of comorbidities and clinical status on survival. Patients and Methods. We included patients ≥ 65-year-old. We collected information about clinical and molecular features, extent of resection, adjuvant treatments, treatment-related complications, and outcome. Results. We included 135 patients. Median age was 71 years. In total, 127 patients (94.0%) had a Karnofsky Performance Status (KPS) ≥70 and 61/135 (45.2%) a Charlson Comorbidity Score (CCI) > 3. MGMTp methylation was found in 70/135 (51.9%). Subtotal resections (STRs), gross-total resections (GTRs), and biopsies were 102 (75.6%), 10 (7.4%) and 23 (17.0%), respectively. Median progression-free survival and overall survival (mOS) were 8.0 and 10.5 months for the whole cohort. Notably, GTR and radio-chemotherapy with temozolomide in patients with MGMTp methylation were associated with significantly longer mOS (32.8 and 44.8 months, respectively). In a multivariable analysis, risk of death was affected by STR vs. GTR (HR 2.8, p = 0.002), MGMTp methylation (HR 0.55, p = 0.007), and KPS at baseline ≥70 (HR 0.43, p = 0.031). Conversely, CCI and post-surgical complications were not significant. Conclusions. Elderly GBM patients often have a dismal prognosis. However, it is possible to identify a subgroup with favourable clinical and molecular features, who benefit from GTR and radio-chemotherapy with temozolomide. A comprehensive prognostic score is needed to guide treatment modality and predict the outcome.

Published
2022
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18. Management of Extramedullary Intradural Spinal Tumors: The Impact of Clinical Status, Intraoperative Neurophysiological Monitoring and Surgical Approach on Outcomes in a 12-Year Double-Center Experience

Author

Fabio Cofano, Carlotta Giambra, Paolo Costa, Pietro Zeppa, Andrea Bianconi, Marco Mammi, Matteo Monticelli, Giuseppe Di Perna, Carola Vera Junemann, Antonio Melcarne, Fulvio Massaro, Alessandro Ducati, Fulvio Tartara, Francesco Zenga, and Diego Garbossa

Subjects
intradural extramedullary spinal tumors, intraoperative neurophysiological monitoring (IONM), D-wave, minimally invasive approaches, CUSA, Neurology. Diseases of the nervous system, RC346-429
Abstract

Objective: Intradural Extramedullary (IDEM) tumors are usually treated with surgical excision. The aim of this study was to investigate the impact on clinical outcomes of pre-surgical clinical conditions, intraoperative neurophysiological monitoring (IONM), surgical access to the spinal canal, histology, degree of resection and intra/postoperative complications.Methods: This is a retrospective observational study analyzing data of patients suffering from IDEM tumors who underwent surgical treatment over a 12 year period in a double-center experience. Data were extracted from a prospectively maintained database and included: sex, age at diagnosis, clinical status according to the modified McCormick Scale (Grades I-V) at admission, discharge, and follow-up, tumor histology, type of surgical access to the spinal canal (bilateral laminectomy vs. monolateral laminectomy vs. laminoplasty), degree of surgical removal, use and type of IONM, occurrence and type of intraoperative complications, use of Ultrasonic Aspirator (CUSA), radiological follow-up.Results: A total number of 249 patients was included with a mean follow-up of 48.3 months. Gross total resection was achieved in 210 patients (84.3%) mostly in Schwannomas (45.2%) and Meningiomas (40.4%). IONM was performed in 162 procedures (65%) and D-wave was recorded in 64.2% of all cervical and thoracic locations (99 patients). The linear regression diagram for McCormick grades before and after surgery (follow-up) showed a correlation between preoperative and postoperative clinical status. A statistically significant correlation was found between absence of worsening of clinical condition at follow-up and use of IONM at follow-up (p = 0.01) but not at discharge. No associations were found between the choice of surgical approach and the extent of resection (p = 0.79), the presence of recurrence or residual tumor (p = 0.14) or CSF leakage (p = 0.25). The extent of resection was not associated with the use of IONM (p = 0.91) or CUSA (p = 0.19).Conclusion: A reliable prediction of clinical improvement could be made based on pre-operative clinical status. The use of IONM resulted in better clinical outcomes at follow-up (not at discharge), but no associations were found with the extent of resection. The use of minimally invasive approaches such as monolateral laminectomy showed to be effective and not associated with worse outcomes or increased complications.

Published
2020
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19. Fluorescence-Guided Surgery in Glioblastoma: 5-ALA, SF or Both? Differences between Fluorescent Dyes in 99 Consecutive Cases

Author

Pietro Zeppa, Raffaele De Marco, Matteo Monticelli, Armando Massara, Andrea Bianconi, Giuseppe Di Perna, Stefania Greco Crasto, Fabio Cofano, Antonio Melcarne, Michele Maria Lanotte, and Diego Garbossa

Subjects
glioblastoma, high-grade glioma, fluorescence-guided surgery, 5-ALA, sodium fluorescein, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Background: Glioblastoma (GBM) is the most common primary brain tumor. The extent of resection (EOR) has been claimed as one of the most important prognostic factors. Fluorescent dyes aid surgeons in detecting a tumor’s borders. 5-aminolevulinic acid (5-ALA) and sodium fluorescein (SF) are the most used. Only a few studies have directly compared these two fluorophores. Methods: A single center retrospective analysis of patients treated for GBM in the period between January 2018 and January 2021 was built to find any differences in terms of EOR, Karnofsky Performance Status (KPS), and overall survival (OS) on the use of 5-ALA, SF, or both. Results: Overall, 99 patients affected by isocitrate dehydrogenase (IDH) wild-type Glioblastoma were included. 5-ALA was administered to 40 patients, SF to 44, and both to 15. No statistically significant associations were identified between the fluorophore and EOR (p = 0.783) or postoperative KPS (p = 0.270). Survival analyses did not show a selective advantage for the use of a given fluorophore (p = 0.184), although there appears to be an advantageous trend associated with the concomitant use of both dyes, particularly after stratification by MGMT (p = 0.071). Conclusions: 5-Ala and SF are equally useful in achieving gross total resection of the enhancing tumor volume. The combination of both fluorophores could lead to an OS advantage.

Published
2022
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20. Dynamical Properties of Baryons

Author

Egle Tomasi-Gustafsson, Andrea Bianconi, and Simone Pacetti

Subjects
hadron structure, form factors, annihilation and scattering reactions, Mathematics, QA1-939
Abstract

The internal structure of composite particles is conveniently described in terms of form factors (FFs)—these are experimentally accessible in annihilation and scattering of elementary reactions, and are theoretically calculable by all models that describe the properties of particles. FFs depend only on one kinematical variable, q2. This is the four-momentum transferred by the virtual photon that carries the interaction. Important developments in accelerator and detector techniques have brought impressive advances, both by extending the kinematical region and by reaching a higher precision. A critical review on the underlying methods and findings in polarized and unpolarized experiments is presented. The unique role played by polarization in determining the ratio of electric to magnetic form factors in the space-like region, and the extraction of individual form factors in the whole kinematical region, are described. Recent results at electron accelerators and electron–positron colliders confirm the existence of periodical structure in the annihilation cross section. We suggest a global framework which describes the dynamical structure of charge distribution in baryons, in order to build a coherent view of the creation and annihilation of baryonic matter.

Published
2021
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21. Let Me See: Correlation between 5-ALA Fluorescence and Molecular Pathways in Glioblastoma: A Single Center Experience

Author

Francesco Maria Calamo Specchia, Matteo Monticelli, Pietro Zeppa, Andrea Bianconi, Francesco Zenga, Roberto Altieri, Beatrice Pugliese, Giuseppe Di Perna, Fabio Cofano, Fulvio Tartara, Luca Bertero, Paola Cassoni, Antonio Melcarne, Michele Maria Lanotte, and Diego Garbossa

Subjects
glioblastoma, 5-ALA, fluorescence, molecular pathways, extent of resection, IDH1, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
Abstract

Background: Despite the aggressiveness of multimodal treatment, glioblastoma (GBM) is still a challenge for neurosurgeons, neurooncologists, and radiotherapists. A surgical approach is still a cornerstone in GBM therapeutic management, as the extent of resection is strongly related both to overall survival and progression-free survival. From this perspective, the use of photodynamic molecules could represent an interesting tool to achieve maximal and safe resection. Being able to trace the lesion’s edges, indeed, could allow to improve the extent of resection and to minimize residual tumor while sparing normal tissue. The use of 5-aminolevulinic acid (5-ALA) as a photodynamic tracer is well established due to its strict correlation both with cellularity and metabolic activity of the GBM cell clones. Objective: Our study aims to define whether a different molecular asset of GBM (especially investigating IDH 1/2 mutation, proliferation index, and MGMT promoter methylation) results in different fluorescence expression, possibly because of differences in metabolic pathways due to different genotypes. Methods: Patients undergoing surgery for GBM removal at our Institute (Dep. Of Neurosurgery, Ospedale Città della Salute e della Scienza, University of Turin, Italy) were retrospectively reviewed. Patients with histological diagnosis confirmation and to whom 5-ALA was given before surgery were included. The whole surgical procedure was recorded and then analyzed by three different people (a medical student, a resident, and a senior surgeon with an interest in neurooncology and experience in using 5-ALA) and a score was assigned to the different degrees of intraoperative fluorescence. The degree of fluorescence was then matched with the genotype. Results: A trend of grade 2 fluorescence (i.e., ”strong”) was observed in the IDH 1/2 wild-type (WT) genotype, suggesting a more intense metabolic activity in this particular subgroup, while, no or weak fluorescence was observed more often in the IDH 1/2 mutated tumors, suggesting a lower metabolic activity. No relations were found between fluorescence grade and MGMT promoter methylation or, interestingly, cellularity. As a secondary analysis, more epileptogenicity of the IDH 1/2 mutated GBM was noticed, similarly to other recent literature. Conclusion: Our results do not support the use of 5-ALA as a diagnostic tool, or a way to substitute the molecular profiling, but confirm 5-ALA as a powerful metabolic tracer, able to easily detect the pathological cells, especially in the IDH WT genotype, and in this perspective, further studies will be necessary to better describe the metabolic activity of GBM cells.

Published
2021
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22. Practical Algorithm for the management of multisutural craniosynostosis with associated Chiari malformation and/or hydrocephalus

Author

Gelsomina Aruta, Pietro Fiaschi, Marco Ceraudo, Gianluca Piatelli, Valeria Capra, Andrea Bianconi, Andrea Rossi, Francesca Secci, and Marco Pavanello

Subjects
Pediatrics, Perinatology and Child Health, Surgery, Neurology (clinical), General Medicine
Abstract

The association between multisutural craniosynostosis with Chiari malformation (CM), venous hypertension and hydrocephalus is widely described in the literature, especially in children with pediatric craniofacial syndromes. Some efforts have been done in the last years to understand the complex pathogenetic mechanisms underlying this association and several theories have been proposed. However, whatever the pathophysiological mechanism, it is still unclear what is the best management and treatment of CM and hydrocephalus in multisutural craniosynostosis patients. The aim of this study is to report our twenty-five years’experience in treating pediatric patients affected by these rare pathologies, in order to propose a simple and effective therapeutic flow-chart for their management. We collected data of each patient that underwent a cranial vault remodelling for a complex craniosynostosis in our institution in the last 25 years. We recorded data concerning type of craniosynostosis and craniofacial syndromes, presence of ventriculomegaly and Chiari Malformation (CM) at presentation and clinical and radiological follow-up. Therefore, we evaluated the final outcomes (improved, stable, deteriorated) of these patients and created a practical flow-chart that could help physicians to choose the best surgical treatment when different pathological conditions, as CM I or hydrocephalus, affect complex craniosynostosis children. Despite the proposed algorithm comes from a clinical experience on 85% successfully treated patients with multiple craniosynostosis, more extensive and deep studies are needed to better understand CM and hydrocephalus development in such conditions.

Published
2023
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23. A Systematic Review of Amino Acid PET Imaging in Adult-Type High-Grade Glioma Surgery: A Neurosurgeon's Perspective

Author

Raffaele De Marco, Alessandro Pesaresi, Andrea Bianconi, Michela Zotta, Désirée Deandreis, Giovanni Morana, Pietro Zeppa, Antonio Melcarne, Diego Garbossa, and Fabio Cofano

Subjects
supramaximal resection, Cancer Research, Oncology, glioma, glioblastoma, amino acid PET imaging, PET-integrated resection
Abstract

Amino acid PET imaging has been used for a few years in the clinical and surgical management of gliomas with satisfactory results in diagnosis and grading for surgical and radiotherapy planning and to differentiate recurrences. Biological tumor volume (BTV) provides more meaningful information than standard MR imaging alone and often exceeds the boundary of the contrast-enhanced nodule seen in MRI. Since a gross total resection reflects the resection of the contrast-enhanced nodule and the majority of recurrences are at a tumor’s margins, an integration of PET imaging during resection could increase PFS and OS. A systematic review of the literature searching for “PET” [All fields] AND “glioma” [All fields] AND “resection” [All fields] was performed in order to investigate the diffusion of integration of PET imaging in surgical practice. Integration in a neuronavigation system and intraoperative use of PET imaging in the primary diagnosis of adult high-grade gliomas were among the criteria for article selection. Only one study has satisfied the inclusion criteria, and a few more (13) have declared to use multimodal imaging techniques with the integration of PET imaging to intentionally perform a biopsy of the PET uptake area. Despite few pieces of evidence, targeting a biologically active area in addition to other tools, which can help intraoperatively the neurosurgeon to increase the amount of resected tumor, has the potential to provide incremental and complementary information in the management of brain gliomas. Since supramaximal resection based on the extent of MRI FLAIR hyperintensity resulted in an advantage in terms of PFS and OS, PET-based biological tumor volume, avoiding new neurological deficits, deserves further investigation.

Published
2022

24. Foramen Caecum Vein Involved in Dural Arteriovenous Fistula Fed by Sphenopalatine Arteries: A Case Report

Author

Massimiliano Minardi, Luca Francesco Salvati, Diego Garbossa, Andrea Bianconi, Antonio Melcarne, and Giuseppe Palmieri

Subjects
business.industry, Arteriovenous fistula, Case Report, Anatomy, medicine.disease, frontal, medicine.anatomical_structure, Anterior cranial fossa, anterior cranial fossa, Medicine, foramen caecum, business, Vein, foramen caecum vein, Foramen caecum, dural arteriovenous fistula
Abstract

Anterior cranial fossa (ACF) dural arteriovenous fistulas (ACF DAVFs) are an infrequent subtype of cranial DAVFs that are usually fed by the anterior ethmoidal artery (AEA) and ophthalmic artery (OA) branches. Due to the lack of dural venous sinus in the ACF, they directly drain into cortical veins, resulting in high bleeding tendency. For this reason, ACF DAVFs have to be treated regardless of whether they are symptomatic or not. A 74-year-old man, with hypertension history, came to our attention because of ear pain, dizziness, and impaired hearing for 2 months. No other pathological conditions have been found in his medical history. The patient underwent brain magnetic resonance imaging (MRI) scan and subsequently second level diagnostic investigations with digital subtraction angiography (DSA), showing a foramen caecum (FC) patency and a persistent, enlarged, arterialized FC vein (FCV) involved in an incidental ACF DAVF (Cognard IV), fed mainly by sphenopalatine arteries (SPAs) branches bilaterally. The patient underwent open surgery performed by small high frontal craniotomy with DAVFs complete closure and without any complications. To the best of our knowledge, this is the first case ever described of FCV persistence with involvement in an intracranial vascular malformation. It has been managed by surgical intervention that can be considered, despite the large skin incision, a minimally invasive approach with an excellent cosmetic result and minimal risk of complications.

Published
2021

25. Comparative analysis of time-like hyperon form factors

Author

Andrea Bianconi, Egle Tomasi-Gustafsson, Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
baryon, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), annihilation, kinematics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Nuclear Theory, FOS: Physical sciences, structure, hyperon: form factor, Nuclear Experiment, n: form factor
Abstract

Data on hyperon form factors recently obtained from annihilation reactions are compared each other, and to proton and neutron form factors, in terms of two kinematical variables: the transferred momentum square, $q^2$, and the modulus $P$ of the relative momentum between the outgoing baryons. They are critically discussed in terms of possible correlated structures. The present status of the time-like form factor data for baryons is described and suggestions are given on the reactions and the kinematical range where data are desirable in order to clarify the arisen questions., 20 pages, 10 figures

Published
2022
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26. Systematic Review on Tumor Microenvironment in Glial Neoplasm: From Understanding Pathogenesis to Future Therapeutic Perspectives

Author

Andrea Bianconi, Gelsomina Aruta, Francesca Rizzo, Luca Francesco Salvati, Pietro Zeppa, Diego Garbossa, and Fabio Cofano

Subjects
Brain Neoplasms, Macrophages, Organic Chemistry, General Medicine, Glioma, microenvironment, Catalysis, Computer Science Applications, Inorganic Chemistry, Tumor Microenvironment, Humans, GAMs, extracellular vesicles, glioma, microglia, Microglia, Physical and Theoretical Chemistry, Glioblastoma, Molecular Biology, Spectroscopy
Abstract

Despite the multidisciplinary management in the treatment of glioblastomas, the average survival of GBM patients is still 15 months. In recent years, molecular biomarkers have gained more and more importance both in the diagnosis and therapy of glial tumors. At the same time, it has become clear that non neoplastic cells, which constitute about 30% of glioma mass, dramatically influence tumor growth, spread, and recurrence. This is the main reason why, in recent years, scientific research has been focused on understanding the function and the composition of tumor microenvironment and its role in gliomagenesis and recurrence. The aim of this review is to summarize the most recent discovery about resident microglia, tumor-associated macrophages, lymphocytes, and the role of extracellular vesicles and their bijective interaction with glioma cells. Moreover, we reported the most recent updates about new therapeutic strategies targeting immune system receptors and soluble factors. Understanding how glioma cells interact with non-neoplastic cells in tumor microenvironment is an essential step to comprehend mechanisms at the base of disease progression and to find new therapeutic strategies for GBM patients. However, no significant results have yet been obtained in studies targeting single molecules/pathways; considering the complex microenvironment, it is likely that only by using multiple therapeutic agents acting on multiple molecular targets can significant results be achieved.

Published
2022

28. Antiproton-nuclei cross sections with Woods-Saxon potential at low energies

Author

Andrea Bianconi, Giovanni Costantini, Giulia Gosta, Marco Leali, Valerio Mascagna, Stefano Migliorati, and Luca Venturelli

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

The present knowledge of the antinucleons elastic scattering and annihilation processes in matter at low energies is limited to a few nuclei data in a small phase-space. Optical potential models are useful tools for modelling nuclear strong interaction of antinucleons with matter providing predictions at very low energies where data are missing. New calculations of elastic and annihilation cross sections for antiproton with nuclei using an optical potential of Woods-Saxon (WS) shape are presented. Preliminary predictions at low energies for carbon and calcium show clearly-measurable nuclear effects for nuclear elastic cross sections at large angles and momenta greater than 50 MeV/c. Some discrepancies in annihilation cross section comparing predictions and data are present using the same fitting parameters.

Published
2022

29. Anticoagulant therapy in high grade gliomas: a systematic review on state of the art and future perspectives

Author

Pietro Fiaschi, Alessandro Prior, Gianluigi Zona, and Andrea Bianconi

Subjects
medicine.medical_specialty, business.industry, medicine.drug_class, Incidence (epidemiology), Anticoagulant, Heparin, Anticoagulant therapy, Internal medicine, Antithrombotic, medicine, Surgery, In patient, Observational study, Neurology (clinical), business, Evidence synthesis, medicine.drug
Abstract

INTRODUCTION Anticoagulation management in high-grade gliomas is a widely studied but still debated topic, since the increased thrombotic risk is accompanied by the high background rate of intralesional bleeding. Currently, the main challenge when prescribing anticoagulants to HGG patients is to balance the risk between ICH and VTE both in the peri-operative period and in the post-operative follow up during adjuvant chemo and radiotherapic treatment. EVIDENCE ACQUISITION A systematic review according to PRISMA-P guidelines was performed: 12 observational studies were selected, eight retrospective and four prospective Regarding the reviews, 3 were selected, two of which analyzed bleeding complications of anticoagulation therapy and one on thrombotic events. EVIDENCE SYNTHESIS In the selected studies, the risk of VTEs was between 4 and 33%, while in patients with VTEs subsequently subjected to anticoagulant therapy the cases of ICH ranged from 0% to 15.4%. Regarding the reviews, two meta-analysis have evaluated the incidence of ICH in patients undergoing anticoagulation therapy following thromboembolic events, they agree in quantifying the increased risk of bleeding. CONCLUSIONS The results of our review are generally consistent in stating that the thrombotic risk is increased in patients with HGG, suggesting that more extensive antithrombotic prophylaxis could positively impact the outcome of these patients, even if currently there are no conclusive elements in indicating or contraindicating prolonged antithrombotic prophylaxis considering that anticoagulant administration in these patients involves an increased risk of ICH. All the studies examined have considered a prolonged heparin treatment without considering the new oral anticoagulants, so further studies about this topic is needed.

Published
2021

30. Distant Recurrence of a Cerebral Cavernous Malformation in the Vicinity of a Developmental Venous Anomaly: Case Report of Local Oxy-Inflammatory Events

Author

Andrea Bianconi, Luca Francesco Salvati, Andrea Perrelli, Chiara Ferraris, Armando Massara, Massimiliano Minardi, Gelsomina Aruta, Miriam Rosso, Barbara Massa Micon, Diego Garbossa, and Saverio Francesco Retta

Subjects
Organic Chemistry, General Medicine, developmental venous anomaly (DVA), Catalysis, Computer Science Applications, Inorganic Chemistry, sterile inflammation, cerebral cavernous malformation (CCM), cerebrovascular diseases, oxidative stress, Physical and Theoretical Chemistry, Molecular Biology, Spectroscopy
Abstract

Background: Cerebral cavernous malformations (CCMs) are a major type of cerebrovascular lesions of proven genetic origin that occur in either sporadic (sCCM) or familial (fCCM) forms, the latter being inherited as an autosomal dominant condition linked to loss-of-function mutations in three known CCM genes. In contrast to fCCMs, sCCMs are rarely linked to mutations in CCM genes and are instead commonly and peculiarly associated with developmental venous anomalies (DVAs), suggesting distinct origins and common pathogenic mechanisms. Case report: A hemorrhagic sCCM in the right frontal lobe of the brain was surgically excised from a symptomatic 3 year old patient, preserving intact and pervious the associated DVA. MRI follow-up examination performed periodically up to 15 years after neurosurgery intervention demonstrated complete removal of the CCM lesion and no residual or relapse signs. However, 18 years after surgery, the patient experienced acute episodes of paresthesia due to a distant recurrence of a new hemorrhagic CCM lesion located within the same area as the previous one. A new surgical intervention was, therefore, necessary, which was again limited to the CCM without affecting the pre-existing DVA. Subsequent follow-up examination by contrast-enhanced MRI evidenced a persistent pattern of signal-intensity abnormalities in the bed of the DVA, including hyperintense gliotic areas, suggesting chronic inflammatory conditions. Conclusions: This case report highlights the possibility of long-term distant recurrence of hemorrhagic sCCMs associated with a DVA, suggesting that such recurrence is secondary to focal sterile inflammatory conditions generated by the DVA.

Published
2022
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31. Measurement of deeply virtual Compton scattering off He4 with the CEBAF Large Acceptance Spectrometer at Jefferson Lab

Author

T. A. Forest, D. P. Watts, H. Egiyan, F. Sabatié, D. Bulumulla, A. Filippi, Aditya R. Khanal, M. Khandaker, G. Rosner, Andrea Bianconi, D. Payette, Jo H. S., Y. Ghandilyan, H. Voskanyan, W. Kim, R. A. Schumacher, P. Lenisa, S. Bültmann, W. J. Briscoe, E. Pasyuk, Maxime Defurne, N. Markov, B. Torayev, R. Dupre, D. G. Ireland, Carlos A. Salgado, V. Crede, B. A. Clary, M. Contalbrigo, K. Livingston, M. Battaglieri, M. J. Amaryan, B. Yale, G. Costantini, S. Stepanyan, V. P. Kubarovsky, A. Kim, R. De Vita, J. Rowley, Whitney Armstrong, Simonetta Liuti, Krishna Neupane, J. Poudel, O. Pogorelko, K. Wei, S. Fegan, P. Eugenio, Dustin Keller, R. Paremuzyan, G. Khachatryan, Volker D. Burkert, M. L. Kabir, H. Atac, T. B. Hayward, Paolo Rossi, A. S. Biselli, R. Wishart, A. Celentano, R. W. Gothe, M. Guidal, K. Hafidi, V. Mokeev, Larry Weinstein, Gerard Gilfoyle, L. Venturelli, Michael Paolone, E. L. Isupov, D. Sokhan, M. Ehrhart, M. Caudron, M. Osipenko, S. Boiarinov, I. J. D. MacGregor, F. Bossu, A. Vossen, G. Ciullo, Fatiha Benmokhtar, Y. Prok, D. S. Carman, M. Holtrop, O. Soto, N. A. Baltzell, Nikos Sparveris, X. Wei, H. Hakobyan, M. H. Wood, E. Voutier, J. Ritman, S. Diehl, N. Dashyan, A. El Alaoui, B. McKinnon, Luciano Pappalardo, M. Bondì, K. A. Griffioen, Yordanka Ilieva, C. Ayerbe Gayoso, Nicholas Zachariou, J. C. Carvajal, Y. Perrin, V. Chesnokov, L. Barion, U. Shrestha, M. Mirazita, L. Lanza, K. Hicks, W. Phelps, V. Mascagna, D. Marchand, S. Niccolai, Alessandro Rizzo, Alexander Schmidt, I. Bedlinskiy, M. Ripani, P. Chatagnon, M. Ungaro, K. Joo, V. Sergeyeva, J. Zhang, F. X. Girod, N. Tyler, C. Djalali, T. Chetry, S. Strauch, L. Elouadrhiri, S. Joosten, I. I. Strakovsky, A. Deur, D. G. Jenkins, A. Hobart, M. Leali, T. R. O'Connell, N. Pivnyuk, A. D'Angelo, L. El Fassi, S. E. Kuhn, M. Hattawy, P. L. Cole, Martin K. Mayer, A. Kripko, and Y. G. Sharabian

Subjects
Nuclear physics, Physics, Spectrometer, 010308 nuclear & particles physics, 0103 physical sciences, Compton scattering, Perturbative QCD, 010306 general physics, 01 natural sciences
Published
2021
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32. Light dark matter searches with positrons

Author

M. Ungaro, Andrea Bianconi, Michael Wood, A. Italiano, L. Venturelli, Elton Smith, M. Leali, M. Bondì, L. El Fassi, R. De Vita, Enrico Nardi, S. Migliorati, S. Stepanyan, G. Costantini, Paolo Valente, P. L. Cole, Nunzio Randazzo, M. Battaglieri, P. Bisio, Andrea Celentano, M. Spreafico, L. Lanza, V. Mascagna, A. D'Angelo, Luc Darmé, M. De Napoli, Gordan Krnjaic, Elena Santopinto, L. Marsicano, V. Kozhuharov, and Mauro Raggi

Subjects
Dark Photon, dark sector, Physics, Nuclear and High Energy Physics, Particle physics, Dark Photon, Settore FIS/04, Dark matter, FOS: Physical sciences, Electron, High Energy Physics - Experiment, Standard Model, radiation, Hidden sector, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), Positron, Physics::Accelerator Physics, Nuclear fusion, Light dark matter, dark sector, performance, Beam (structure)
Abstract

We discuss two complementary strategies to search for light dark matter (LDM) exploiting the positron beam possibly available in the future at Jefferson Laboratory. LDM is a new compelling hypothesis that identifies dark matter with new sub-GeV "hidden sector" states, neutral under standard model interactions and interacting with our world through a new force. Accelerator-based searches at the intensity frontier are uniquely suited to explore it. Thanks to the high intensity and the high energy of the CEBAF (Continuous Electron Beam Accelerator Facility) beam, and relying on a novel LDM production mechanism via positron annihilation on target atomic electrons, the proposed strategies will allow us to explore new regions in the LDM parameters space, thoroughly probing the LDM hypothesis as well as more general hidden sector scenarios., 11 pages, 8 figures. Prepared for submission in EPJA. This work supersedes the corresponding contribution in arXiv:2007.15081. Added aknowledgement to Jefferson Lab

Published
2021
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33. Prognostic Analysis of the IDH1 G105G (rs11554137) SNP in IDH-Wildtype Glioblastoma

Author

Ayoub Saaid, Matteo Monticelli, Alessia Andrea Ricci, Giulia Orlando, Cristina Botta, Pietro Zeppa, Andrea Bianconi, Simona Osella-Abate, Francesco Bruno, Alessia Pellerino, Roberta Rudà, Paola Cassoni, Diego Garbossa, Fabio Cofano, and Luca Bertero

Subjects
Brain Neoplasms, Mutation, Genetics, Humans, Glioma, IDH1, glioblastoma, rs11554137, SNP, prognosis, Glioblastoma, Prognosis, Polymorphism, Single Nucleotide, Isocitrate Dehydrogenase, Genetics (clinical)
Abstract

The G105G SNP (rs11554137) in the IDH1 gene is observed in about 10–15% of patients with a diffuse glioma. Data regarding its impact on gliomas are poor and partially conflicting, possibly due to the evolving classification of CNS tumors. The aim of this study was to investigate the G105G SNP prognostic significance in a homogenous cohort of IDH-wildtype glioblastomas, in agreement with the 2021 WHO classification. The study analyzed 211 patients by collecting several clinico-pathological and molecular characteristics, including the age, lesion localization, number of involved lobes, type of surgical treatment, disease outcome and MGMT promoter methylation status. PFS and DSS curves were plotted according to the Kaplan–Meier method and statistical analyses were performed using parametric and non-parametric tests. A total of 32 patients out of 211 (15.2%) were found to be G105G SNP carriers. No significant impact of the IDH1 G105G SNP on patients’ outcomes was observed in terms of PFS and DSS, while MGMT promoter methylation and gross total resection resulted as key prognostic factors in our cohort as expected. No prognostic impact of the IDH1 G105G SNP was detected in this strict cohort of IDH-wildtype glioblastomas. Analysis of larger cohorts is warranted to address the sample size limitations.

Published
2022
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34. Long-term functional recovery in C5-C6 avulsions treated with distal nerve transfers

Author

Andrea Bianconi, Crescenzo Capone, Carlo Sacco, Irene Fasce, Pietro Fiaschi, and Guido Staffa

Subjects
Surgical repair, medicine.medical_specialty, brachial plexus lesions, business.industry, Elbow, nerve repair, General Medicine, arm function restoration, cervical avulsion, Nerve transfer, Biceps, Surgery, body regions, Avulsion, medicine.anatomical_structure, Neurology, Nerve Transfer, Medicine, Supinator muscle, Neurology (clinical), business, Brachial plexus, Reinnervation
Abstract

Background In patients suffering from traction lesions of the brachial plexus, complete C5 and/or C6 root avulsion patients with C7 root preservation are relatively uncommon occurrences, but represent excellent candidates for surgical treatment, with satisfactory results. Shoulder abduction and extra-rotation, elbow flexion and forearm supination are lost functions restorable with surgical treatment. Methods This single-center, prospective observational study involved a series of 27 young adults with C5 and/or C6 root complete avulsion and C7 preservation, which underwent surgical repair with double or triple nerve transfer. Results Patients recovered a useful elbow flexion. Electromyographic and clinical signs of biceps reinnervation were observed in each UN-MC nerve transfer. The abduction strength recovery was M5 in 10 patients, M4 in 14 patients and M3 in 3 patients. The external rotation strength recovery was M5 in 4 patients, M4 in 18 patients, M3 in 3 patients and M2 in 2 patients. The elbow flection strength was M5 in 5 patients, M4 in 15 patients and M3 in 7 patients. Elbow extension was preserved in all cases. Conclusions The concept of 'peripheral rewiring procedures' represents an advance in the repair of the peripheral nerve injuries. Triple nerve transfer can be nowadays considered a standard treatment for isolated C5-C6 avulsions. We report our experience with the second-biggest casuistry in the literature on patients treated with this technique. We consider our outcome concerning functional recovery to be satisfying and comparable to data reported in the literature.

Published
2021

35. Observation of Beam Spin Asymmetries in the Process ep→e′π+π−X with CLAS12

Author

G. Niculescu, D. Bulumulla, G. Ciullo, Aditya R. Khanal, A. El Alaoui, S. Niccolai, E. L. Isupov, D. S. Carman, F. X. Girod, Nikos Sparveris, K. A. Griffioen, D. G. Ireland, V. I. Mokeev, M. Contalbrigo, V. Crede, Nicholas Zachariou, J. C. Carvajal, Sung-Sik Lee, X. Wei, S. Boiarinov, Andrea Bianconi, P. Lenisa, C. Dilks, Fatiha Benmokhtar, O. Soto, T. B. Hayward, M. Osipenko, R. Paremuzyan, L. Marsicano, Maxime Defurne, B. A. Clary, Latifa Elouadrhiri, A. Movsisyan, N. Tyler, N. Markov, P. L. Cole, N. Dashyan, K. Hicks, I. J. D. MacGregor, S. Strauch, D. I. Glazier, V. P. Kubarovsky, Michael Paolone, Krishna Neupane, H. Hakobyan, F. Bossu, R. Tyson, J. Ritman, Eugene Pasyuk, R. De Vita, D. Marchand, H. S. Jo, H. Avakian, Eric Voutier, L. Lanza, S. Diehl, C. Salgado, A. A. Golubenko, H. Atac, H. Voskanyan, G. Costantini, W. J. Briscoe, L. Barion, S. E. Kuhn, M. Hattawy, A. Vossen, M. Guidal, A. D'Angelo, Dustin Keller, M Ehrhart, P. Naidoo, T. Chetry, D. P. Watts, P. Chatagnon, Y. Prok, U. Shrestha, Michael Wood, F. Sabatié, M. Holtrop, Chaden Djalali, L. El Fassi, V. Mascagna, G. Gavalian, K. Hafidi, A. Filippi, B. A. Raue, Luciano Pappalardo, C. Ayerbe Gayoso, I. Bedlinskiy, Michael Dugger, W. Phelps, G. Angelini, P. Rossi, K. Wei, S. Joosten, S. Fegan, M. Leali, A. Celentano, R. W. Gothe, P. Nadel-Turonski, M. Khachatryan, N. A. Baltzell, K. Livingston, Alessandro Rizzo, Axel Schmidt, T. R. O'Connell, William Brooks, I. I. Strakovsky, F. Hauenstein, A. Kim, L. Venturelli, Jie Zhang, Y. Gotra, Z. E. Meziani, A. Deur, B. Yale, E.P. Segarra, S. Nanda, A. Kripko, T. A. Forest, S. Stepanyan, Y. G. Sharabian, M. Ripani, R. Dupré, M. Bondì, M. Battaglieri, O. Pogorelko, J. Rowley, Volker D. Burkert, A. S. Biselli, A. Hobart, S. Adhikari, B. McKinnon, M. Mirazita, Gerard Gilfoyle, D. Sokhan, M. Arratia, Hovanes Egiyan, C. Munoz Camacho, M. Ungaro, K. Joo, A. Thornton, and W. Kim

Subjects
Quark, Physics, Spectrometer, Proton, Nuclear Theory, General Physics and Astronomy, Deep inelastic scattering, 01 natural sciences, Gluon, Nuclear physics, 0103 physical sciences, Cathode ray, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Beam (structure), Spin-½
Abstract

The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported for the first time. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first observation of a signal that can be used to extract the PDF $e(x)$ in a collinear framework and the helicity-dependent two-pion fragmentation function $G_1^\perp$.

Published
2021
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36. Photoproduction of the f2(1270) Meson Using the CLAS Detector

Author

V. Mokeev, P. Eugenio, Vincent Mathieu, D. Heddle, R. A. Schumacher, M. Battaglieri, K. A. Griffioen, R. Paremuzyan, Laura Clark, L. Marsicano, L. Lanza, M. J. Amaryan, M Carver, G. Angelini, D. P. Watts, Gerard Gilfoyle, M. Osipenko, N. Gevorgyan, P. Lenisa, M. Contalbrigo, H. Egiyan, K. Livingston, R. Tyson, D. Sokhan, S. Stepanyan, I. J. D. MacGregor, F. X. Girod, S. Adhikari, Dustin Keller, F. Sabatié, B. McKinnon, G. Niculescu, G. Rosner, B. A. Clary, D. G. Ireland, V. Crede, D. Bulumulla, William Brooks, E. Munevar, Jie Zhang, T. B. Hayward, K. Hafidi, A. Filippi, W. Phelps, Z. E. Meziani, B. Yale, Aditya R. Khanal, L. Venturelli, M. Ehrhart, M. Khandaker, E. L. Isupov, Friedrich Klein, Alessandro Rizzo, A. Kim, Michael Paolone, S. Boiarinov, Andrea Bianconi, G. Ciullo, A. Pilloni, C. W. Kim, A. Celentano, R. W. Gothe, Y. Prok, C. E. Hyde, I. Bedlinskiy, A. El Alaoui, N. A. Baltzell, F. Bossu, T. Chetry, D. S. Carman, Nicholas Zachariou, H. S. Jo, U. Shrestha, J. C. Carvajal, H. Voskanyan, Z. W. Zhao, Fatiha Benmokhtar, Nikos Sparveris, X. Wei, W. J. Briscoe, O. Soto, V. Mascagna, Maxime Defurne, M. Holtrop, S. Joosten, S. Niccolai, D. Protopopescu, E. Voutier, Luciano Pappalardo, A. Movsisyan, R. De Vita, H. Hakobyan, O. Pogorelko, S. Strauch, J. Ritman, J. Rowley, A. I. Ostrovidov, P. Chatagnon, K. Wei, S. Diehl, C. Salgado, S. Fegan, H. Atac, Volker D. Burkert, C. Munoz Camacho, Eugene Pasyuk, A. S. Biselli, G. Gavalian, V. P. Kubarovsky, Krishna Neupane, M. Ripani, M. Hattawy, K. Hicks, N. Dashyan, Michael Dugger, Yordanka Ilieva, L. Barion, Barry Ritchie, R. Dupre, D. Marchand, M. Ungaro, G. V. Fedotov, Q. Huang, K. P. Adhikari, K. Joo, D. G. Jenkins, M. Leali, Axel Schmidt, I. I. Strakovsky, P. Nadel-Turonski, A. Deur, Mark W. Bondi, M. E. McCracken, N. Tyler, C. Djalali, A. D'Angelo, L. El Fassi, A. Kripko, Y. G. Sharabian, and P. L. Cole

Subjects
Quark, Physics, Spectrometer, Meson, High Energy Physics::Lattice, Nuclear Theory, Quark model, Detector, General Physics and Astronomy, Quantum number, 01 natural sciences, 7. Clean energy, Resonance (particle physics), Nuclear physics, Pion, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics
Abstract

The quark structure of the f2(1270) meson has, for many years, been assumed to be a pure quark-antiquark (qq¯) resonance with quantum numbers JPC=2++. Recently, it was proposed that the f2(1270) is a molecular state made from the attractive interaction of two ρ mesons. Such a state would be expected to decay strongly to final states with charged pions due to the dominant decay ρ→π+π-, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction γp→π0π0p, using the CEBAF Large Acceptance Spectrometer detector at Jefferson Lab for incident beam energies between 3.6 and 5.4 GeV. Differential cross sections, dσ/dt, for f2(1270) photoproduction are extracted with good precision due to low backgrounds and are compared to theoretical calculations.

Published
2021
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37. Beam Spin Asymmetry in Semi-Inclusive Electroproduction of Hadron Pairs

Author

K. Park, V. P. Kubarovsky, Krishna Neupane, C. W. Kim, H. Avakian, H. Voskanyan, W. J. Briscoe, Dustin Keller, P. Eugenio, Michael Wood, K. Hafidi, G. Gavalian, L. Marsicano, A Hobart, V. Mokeev, F. X. Girod, R. A. Schumacher, M. Battaglieri, I. I. Strakovsky, R. W. Gothe, T. Chetry, M. J. Amaryan, F. Sabatié, K. Wei, S. Fegan, N. Markov, L. Guo, Alessandro Rizzo, K. A. Griffioen, Fatiha Benmokhtar, Gerard Gilfoyle, R. Paremuzyan, E. L. Isupov, A. Deur, S. Pisano, V. Crede, Ross Milner, O. Soto, P. Lenisa, M. Contalbrigo, C. Dilks, L. Lanza, M. Ungaro, T. A. Forest, C. Mullen, W. K. Brooks, M. Guidal, Z. W. Zhao, S. Stepanyan, N. A. Baltzell, M. Holtrop, T. B. Hayward, Friedrich Klein, Andrea Celentano, O. Pogorelko, J. Poudel, A. Filippi, Brian Raue, K. Hicks, K. Joo, D. Marchand, M. Osipenko, Luciano Pappalardo, K. L. Giovanetti, Hovanes Egiyan, M. Ripani, C. Munoz Camacho, A. D'Angelo, B. Yale, S. Adhikari, L. Venturelli, B. McKinnon, M. Ehrhart, D. G. Ireland, Tim O'Connell, I. Bedlinskiy, D. I. Glazier, W. Phelps, D. G. Jenkins, N. Tyler, M. Leali, L. El Fassi, C. Djalali, Volker D. Burkert, W. Kim, T. Mineeva, D. Heddle, R. De Vita, G. Ciullo, V. Mascagna, H. S. Jo, A. S. Biselli, M. Mirazita, D. Bulumulla, Y. Prok, D. S. Carman, G. Niculescu, B. S. Ishkhanov, E. Pasyuk, Aditya R. Khanal, X. Wei, R. G. Fersch, Andrea Bianconi, H. Atac, P. L. Cole, N. Dashyan, G. Angelini, P. Chatagnon, B. A. Clary, P. Rossi, M. Defurne, Michael Paolone, L. Barion, Axel Schmidt, Aurore Courtoy, K. Livingston, M. Khandaker, Jie Zhang, I. J. D. MacGregor, E. Golovatch, R. Dupre, Y. Ghandilyan, Q. Huang, E. Voutier, A. Vossen, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, J. C. Carvajal, S. Strauch, D. P. Watts, F. Bossu, Nikolaos Sparveris, Dinko Pocanic, S. E. Kuhn, M. Hattawy, Y. G. Sharabian, S. Boiarinov, H. Hakobyan, J. Ritman, S. Diehl, C. Salgado, U. Shrestha, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS

Subjects
High Energy Physics::Lattice, Nuclear Theory, Hadron, parton: distribution function, General Physics and Astronomy, Parton, 01 natural sciences, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), Economica, higher-twist, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), electron: beam, Nuclear Experiment, dimension: 1, Physics, Quantum chromodynamics, deep inelastic scattering: semi-inclusive reaction, Settore FIS/04, nucleon, kinematics, Quarks and Gluons, helicity distributions, quark: valence, Nucleon, Jefferson Lab, Quark, Particle physics, polarization: longitudinal, FOS: Physical sciences, Socio-culturale, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Transversity Distributions, hadron: electroproduction, hadron: pair production, Pion, CLAS, Hadron Physics, quantum chromodynamics, 0103 physical sciences, ddc:530, 010306 general physics, High Energy Physics::Phenomenology, Ambientale, Deep inelastic scattering, spin: asymmetry: measured, Distribution function, Elementary Particles and Fields, QCD Dynamics, High Energy Physics::Experiment, pi: pair production, experimental results
Abstract

Physical review letters 126(6), 062002 (2021). doi:10.1103/PhysRevLett.126.062002, Published by APS, College Park, Md.

Published
2021
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38. The potential of $\varLambda $ and $\varXi ^-$ studies with PANDA at FAIR

Author

M. Sachs, I. K. Keshk, Xi-Guang Cao, M. Traxler, Yan Liang, G. Mazza, C. Fritzsch, T. Holtmann, S. Godre, A. N. Skachkova, Edward Lisowski, E. Rosenthal, S. Yogesh, Y. K. Sun, H. Pace, D. A. Morozov, H. Deppe, J. Pütz, A. G. Denig, S. Ryzhikov, Hans-Georg Zaunick, Dirk Grunwald, A. Kantsyrev, Paolo Mengucci, Christoph Herold, P. Eugenio, Grzegorz Filo, A. Boukharov, M. Kesselkaul, Concettina Sfienti, A. Kulkarni, M. Lattery, J. Frech, A. Hayrapetyan, W. Zhu, A. A. Piskun, Zbigniew Rudy, V. E. Blinov, S. Spataro, Jens Hartmann, S. Schlimme, D. Branford, C. Schwarz, Michaela Thiel, G. Golovanov, T. Wasem, J. Schwiening, P. Wieczorek, E. Pyata, Ch. Hammann, D. Lehmann, Chinorat Kobdaj, V. Moiseev, P. Balanutsa, B. J. Liu, S. Bodenschatz, F. E. Maas, N. Wongprachanukul, Lorenzo Scalise, M. Hoek, A. K. Saxena, M. Virius, M. Steinke, N. Rathod, A.A. Efremov, A. Samartsev, I. Shein, Alexander Olshevskiy, Herbert Koch, V. Panjushkin, K. Nowakowski, S. Belostotski, S. Bukreeva, Ulrich Wiedner, U. Thöring, A.S. Vodopianov, J. Kellers, L. Robison, Ting Xiao, V. Crede, Egle Tomasi-Gustafsson, R. Karabowicz, P. Srisawad, F. Feldbauer, J. Reher, D. Kazlou, M. Yu. Barabanov, W. Kühn, M. Steinen, P. Wintz, D. Wölbing, A. Dbeyssi, M. Kunze, C. Hargens, A. Pitka, A. Lehmann, I. Augustin, Mathias Fink, P. Terlecki, A. E. Yakutin, Magnus Wolke, I. Kisel, V. Varentsov, U. Thoma, Nicola Bianchi, D. Bettoni, Antoni Szczurek, Dan Pantea, M. Slunecka, D. I. Glazier, H. H. Leithoff, Genady Gavrilov, P. Jiang, T. Simantathammakul, Felice Iazzi, E. Widmann, D. G. Ireland, C. Motzko, K.-T. Brinkmann, M. Schmidt, Johann Marton, J. Tao, W. Eyrich, M. Straube, Krzysztof Swientek, B. Krusche, N. K. Walford, S. Vejdani, G. Perez Andrade, Richard Wheadon, N. Kratochwil, H. Li, L. Jokhovets, S.G. Pivovarov, W. Ikegami Andersson, S. Grieser, A. Gerhardt, H. Qi, W. Lauth, S. Diehl, R. Beck, Krzysztof Korcyl, Angelo Rivetti, K. Makonyi, Yupeng Yan, P. P. Natali, G. Kesik, K. N. Basant, I. Lehmann, A. V. Stavinskiy, W. Esmail, M. Preston, A. Gillitzer, D. Calvo, Ayut Limphirat, A. Demekhin, J. Müllers, M. Pelizäus, Andrew Levin, Gianangelo Bracco, N. Quin, D. Lersch, V. Chernetsky, M. Domagala, N. Minaev, A. Balashoff, U. Müller, N. Hüsken, V. Abramov, Torbjörn Bäck, A. Ali, S. Pflüger, C. Yu, G. Boca, R. Klasen, N. Kristi, J. Zmeskal, T. Nasawad, A. Dolgolenko, A. Belousov, B. Wohlfahrt, H. Xu, R. Dosdall, E. Maslova, Gianni Barucca, M.P. Bussa, B. Seitz, J. S. Díaz, G. Hunter, M. Volf, V.Kh. Dodokhov, Piotr Lebiedowicz, A. Scholl, Grzegorz Korcyl, H. Loehner, Mohammed Al-Turany, Andrzej Kupsc, R. W. Novotny, L. Montalto, A. E. Blinov, J. Kannika, Andrey Uzunian, R. Lalik, P. N. Deepak, P.-E. Tegnér, E. Antokhin, A. Gerasimov, P. De Remigis, X. Zhou, Petr Gallus, P. Orsich, I. Prochazka, Valentino Rigato, S. Maldaner, M. Himmelreich, V. M. Abazov, J. Płażek, Kazem Azizi, James Ritman, S. Wolff, Andrea Bianconi, Nicola Paone, W. Nalti, S. Kegel, I. A. Kuyanov, M. Steinacher, A. Chlopik, V. Lucherini, A. Belias, K. K. Seth, Mario Bragadireanu, C. J. Schmidt, V. Freudenreich, A. Ehret, G. V. Fedotov, J. Li, A. Galoyan, G. Neue, P. Schakel, M. Wojciechowski, B. Kopf, C. Liu, P. Gianotti, X. Ma, R. Kappert, Oleg V. Missevitch, J. Pereira-de-Lira, X. Zhang, D. Melnychuk, Paweł Moskal, I. Köseoglu, Bo Cederwall, K. Götzen, M. Finger, M. Marcisovsky, A. Derevschikov, V. Goryachev, V. Jary, R. Kunne, Y. Zhou, G. Reicherz, C. Schnier, J. G. Messchendorp, M. Michałek, T. Erlen, D. Miehling, G. D. Alexeev, Hasko Stenzel, A. Fechtchenko, L. Schmitt, J. Rieger, M. Zyzak, Michael Papenbrock, F. Schupp, Sean A Dobbs, J. Pochodzalla, S. Chernichenko, S. Shimanski, A. Mustafa, K. Dutta, M. Kümmel, S. Bökelmann, S. Sun, Bruce Yabsley, I. Zimmermann, E.K. Koshurnikov, B. Zwieglinski, O. Malyshev, H. Flemming, O. Korchak, U. Kurilla, F. Nerling, M. Pugach, Claude Amsler, G. Huang, A. Akram, L. Sohl, B. J. Roy, S. Wronka, Andrey V. Izotov, Vaclav Vrba, A. Malige, M. Kuhlmann, E. Prencipe, R. Böhm, R. Schubert, Matthias Richter, M. Krebs, L. Nogach, Frank Goldenbaum, B. Ramstein, X. Y. Shen, Paul Alois Buhler, S. I. Manaenkov, A. Aycock, M. Küßner, A. Khoukaz, E. Luschevskaya, K. Khosonthongkee, C. Wenzel, M. Pfaffinger, J. Lühning, P. Poznański, Fabrizio Daví, S. Koch, O. Corell, M. Kavatsyuk, Bernd Voss, B. Hetz, Daniele Rinaldi, J. Regina, L. Capozza, J. Novy, V. Ferapontov, A. Kozela, D. Y. Kirin, U. Lynen, T. Johansson, S. Orfanitski, M. Tomasek, A. Derichs, Andrea Lavagno, Krisztian Peters, A. Ryazantsev, Daniel Duda, Valery Dormenev, M. Peskova, X. A. Xiong, O. Noll, M. Rossbach, M. Fritsch, N. I. Zhuravlev, Tomasz Fiutowski, S. Zimmermann, Y. Melnik, V. A. Matveev, A. Täschner, P. Salabura, S.A. Kononov, T. Triffterer, J. S. Lange, K. Pysz, K. Kalita, W. Erni, Ajay Kumar Rai, D. P. Watts, Lennart Isaksson, Utpal N. Roy, M. Strickert, M. Böhm, M. Albrecht, Y. Bettner, Boris Batyunya, A. Hamdi, J. Hofmann, Jize Zhao, R. Dzhygadlo, T. Held, V. V. Tokmenin, K. Manasatitpong, Andrei Fedorov, H. Orth, Hans Calén, M. Urban, G. Zhao, F. Lisowski, Witold Przygoda, D. Prasuhn, M. Zambrana, W. Schäfer, S. Bleser, A. K. Hergemöller, M. Pesek, Y. A. Tikhonov, A. Filippi, M. Peter, Volker Metag, M. Moritz, A. Kripko, J. Tarasiuk, S. Schadmand, G. Schepers, S. Poslavskiy, Andreas Martin Heinz, Anne-Laure Martin, L. Brück, Antonin Kveton, V. Mochalov, D. Steinschaden, M. Bölting, N. Er, Ch. Schmidt, Mikhail Korzhik, V. Astakhov, Konstantin Beloborodov, H. Denizli, T. Saito, R. Hagdorn, Pawel Marciniewski, D. Veretennikov, C. Morales Morales, Harphool Kumawat, Karin Schönning, Marek Idzik, M. O. Distler, A. Golubev, E. Ladygina, G. Kozlov, Tobias Stockmanns, C. Hahn, N. Cao, T. Sefzick, Giovanni Lancioni, V. Serdyuk, B. Ketzer, Jerzy Smyrski, D. Bonaventura, P. Wüstner, Yu. Yu. Lobanov, V. Pothodi Chackara, Mariana Nanova, B. Salisbury, E. A. Kravchenko, L. Tomasek, D. Bumrungkoh, Patrick Achenbach, W. Alkakhi, V. Uzhinsky, Y. Goncharenko, Harald Merkel, A. Atac, D. Rodríguez Piñeiro, A. Verkheev, P. Fedorets, S. Nakhoul, F. H. Heinsius, Q. Hu, N. B. Skachkov, S. Pongampai, R. Schmitz, E. A. Strokovsky, Zhiyong Liu, H. Peng, V. Arefiev, K. Föhl, D. Liu, P. Semenov, V. Rodin, Keval Gandhi, P. Kulessa, O. Miklukho, A. Vasiliev, P. Brand, A. A. Zhdanov, R. Kliemt, P. Grasemann, A. Yu. Barnyakov, Z. Li, A. Meschanin, Michael Düren, S. Ahmed, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), PANDA, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), BAİBÜ, Fen Edebiyat Fakültesi, Fizik Bölümü, Denizli, Haluk, and 0-Belirlenecek

Subjects
+Antixi+Xi%22">anti-p p --> Antixi Xi, Hadron, hyperon: pair production, correction: efficiency, 01 natural sciences, 13.30.-a, symmetry: CP, High Energy Physics - Experiment, Subatomär fysik, benchmark, Subatomic Physics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Electromagnetic Form-Factors, Nuclear Experiment, Spin-½, Physics, Antihyperon Production, Hyperon, PANDA, strong interaction, Observable, hyperon: production, 13.88.+, +Antilambda+Lambda%22">anti-p p --> Antilambda Lambda, Production (computer science), Low-Energy, Nuclear and High Energy Physics, Particle physics, Cp-Violation, +Lambda+pi%22">Xi- --> Lambda pi, Bar (music), spin: correlation, Strong interaction, Hyperons, nonperturbative, 13.60.R, hyperon: decay, 0103 physical sciences, anti-p p: scattering, ddc:530, anti-p: beam, 010306 general physics, polarization, 010308 nuclear & particles physics, background, High Energy Physics::Phenomenology, antihyperon, [No Keywords], Exchange, 13.75.-n, Decay, hyperon: ground state, Antiproton, High Energy Physics::Experiment
Abstract

The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: $\bar{p}p \to \bar{\Lambda}\Lambda$ and $\bar{p}p \to \bar{\Xi}^+\Xi^-$. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA., Comment: 26 pages, 16 figures. Changes: Revised title and abstract and corrections/clarifications in the text according to suggestions by journal referees

Published
2021
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39. An experimental program with high duty-cycle polarized and unpolarized positron beams at Jefferson Lab

Author

Anthony W. Thomas, M. Battaglieri, R. De Vita, D. Marchand, Latifa Elouadrhiri, S. Habet, Hubert Spiesberger, P. Gueye, David Hamilton, Giovanni Salmè, A. Filippi, Pete Markowitz, D. Perera, G. Kalicy, M. Muhoza, N. Kalantarians, H. Atac, M. Khandaker, J. Xie, F. Sabatié, M. Mazouz, Ashot Gasparian, I.P. Fernando, V. Klimenko, T. A. Forest, D. McNulty, Z. E. Meziani, M. Boer, M. McCaughan, A. Asaturyan, J. P. Chen, V. Kozhuharov, S. Stepanyan, Simonetta Liuti, T. Patel, Alberto Accardi, M. Spata, Andrew Puckett, Andreas Metz, Salina Ali, V. Bellini, L. Barion, V. V. Berdnikov, Alexandre Camsonne, P. E. Reimer, M. Shabestari, P. Bisio, Simon Širca, T. Averett, J. Kim, Nikolaos Sparveris, M. Poelker, M. Spreafico, H. F. Ibrahim, Dipangkar Dutta, V. Bertone, Bogdan Wojtsekhowski, Ross Milner, H. Avakian, C. E. Hyde, P. M. King, Marc Vanderhaeghen, A. Somov, Yulia Furletova, Miha Mihovilovič, V. Tadevosyan, P. Sznajder, S. Migliorati, R. S. Beminiwattha, T. Chetry, M. Guidal, Olfred Hansen, T. Kutz, Z. W. Zhao, Barbara Pasquini, Eric Voutier, L. Lanza, M. J. Amaryan, J. R. M. Annand, Fatiha Benmokhtar, T. Gautam, H. Voskanyan, Richard Trotta, Ian L. Pegg, J. F. Owens, W. J. Briscoe, Jingyi Zhou, P. Valente, M. N. H. Rashad, Gordan Krnjaic, P. Lenisa, Elena Santopinto, Joseph Grames, M. Leali, S. Zhamkochyan, M. Caudron, Kai-Thomas Brinkmann, Elton Smith, L. Marsicano, Andrei Afanasev, Luciano Pappalardo, M. Carmignotto, Donal Day, L. Venturelli, Eugene Pasyuk, M. Ungaro, C. Peng, L. Causse, D. Hasell, G. Costantini, Douglas Higinbotham, N. D’Hose, J. Murphy, P. Chatagnon, R. Dupré, M. Bondì, Alexander Ilyichev, Matteo Rinaldi, P. Stoler, Brian Raue, G. N. Grauvogel, R. Santos Estrada, Kondo Gnanvo, K. Price, Q. Liu, S. Diehl, J. Nazeer, Y. G. Sharabian, X. Zheng, S. Niccolai, P. G. Blunden, J. Arrington, Riad Suleiman, J. Erler, S. Joosten, Andrea Bianconi, H.-S. Ko, P. L. Cole, Nilanga Liyanage, I. Albayrak, K. Joo, Jan C. Bernauer, F.-X. Girod, D. Gaskell, A. Kim, Juliette Mammei, A. Italiano, M. Hattawy, C. Ayerbe Gayoso, I. I. Strakovsky, M. Yurov, N. Randazzo, A. Deur, Wally Melnitchouk, H.-G. Zaunick, Michael Kohl, A. D'Angelo, E. Nardi, M. Paolone, C. Zorn, L. El Fassi, B. T. Kriesten, L. Darmé, M. Rathnayake, A. Shahinyan, Jie Zhang, Alessandro Rizzo, D. Flay, W. Xiong, H. Dutrieux, V. Sergeyeva, S. Zhang, E. R. Kinney, Hervé Moutarde, B. Dongwi, Axel Schmidt, Rolf Ent, S. Zhao, Volker D. Burkert, A. S. Tadepalli, A. S. Biselli, Tanja Horn, G. Niculescu, T. Cao, A. Celentano, P. Nadel-Turonski, Ethan Cline, J. Roche, B. Karky, M. Contalbrigo, H. Szumila-Vance, S. Fucini, O. Rondon-Aramayo, M. De Napoli, V. Mascagna, E. Fuchey, L. Cardman, G. Ciullo, Haiyan Gao, Cynthia Keppel, M. Ehrhart, A. Movsisyan, R. Novotny, A. Hobart, Sergio Scopetta, B. McKinnon, S. A. Wood, H. Mkrtchyan, M. Tiefenback, C. Munoz Camacho, Xinzhan Bai, R. Paremuzyan, B. Sawatzky, D. Sokhan, M. Suresh, Markus Diefenthaler, Z. Ye, Mauro Raggi, M. Kerver, Y. Roblin, A. Mkrtchyan, V. P. Kubarovsky, R. Capobianco, T. J. Hague, Dustin Keller, Sonny Mantry, Vladimir Khachatryan, Peter Schweitzer, Michael Wood, Maxime Defurne, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
cross-section, ratio, Photon, parton distributions, elastic scattering, Parton, polarized beam, Electron, Leptons Accelerators, Structure of Nucleons, 7. Clean energy, 01 natural sciences, Dark photon, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), Positron, Economica, electromagnetic form-factors, virtual compton-scattering, generalized, squared 4-momentum transfers, lepton-flavor, violation, electron-proton, parity violation, pair production, Physics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Experiment (nucl-ex), Nuclear Experiment, Elastic scattering, Dark sector, JLab, dark photon, Settore FIS/04, lepton: flavor: violation, nucleon: generalized parton distribution, 3. Good health, High Energy Physics - Phenomenology, Elastic and deep inelastic Scattering, Nucleon, Jefferson Lab, Nuclear and High Energy Physics, nucleon: form factor: electromagnetic, FOS: Physical sciences, Socio-culturale, helium: target, Context (language use), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Nuclear physics, PE2_2, PE2_1, deeply virtual Compton scattering, 0103 physical sciences, quantum chromodynamics, 010306 general physics, PE2_3, activity report, exchange: two-photon, electroweak interaction, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Ambientale, positron: beam, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], charge: asymmetry, Positron Beams, Physics::Accelerator Physics, proposal, High Energy Physics::Experiment
Abstract

Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental programs at the next generation of lepton accelerators. In the context of the hadronic physics program at Jefferson Lab (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of nucleons and nuclei, in both the elastic and deep-inelastic regimes. For instance, elastic scattering of polarized and unpolarized electrons and positrons from the nucleon enables a model independent determination of its electromagnetic form factors. Also, the deeply-virtual scattering of polarized and unpolarized electrons and positrons allows unambiguous separation of the different contributions to the cross section of the lepto-production of photons and of lepton-pairs, enabling an accurate determination of the nucleons and nuclei generalized parton distributions, and providing an access to the gravitational form factors. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model of particle physics through the search of a dark photon, the precise measurement of electroweak couplings, and the investigation of charged lepton flavor violation. This document discusses the perspectives of an experimental program with high duty-cycle positron beams at JLab., Comment: 18 pages, 7 figures This version superseeds the previous version which scientific content was decomposed into several more elaborated articles. All of these articles will be collected in the EPJ A Topical Issue about "Positron beam and physics at Jefferson Lab (e+@Jlab)"

Published
2021
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40. Study of excited $$arvec{arXi }$$ baryons with the $$overline{ ext{ P }}$$ANDA detector

Author

Egle Tomasi-Gustafsson, R. Karabowicz, A. Kripko, M. Domagala, U. Müller, Pawel Marciniewski, D. Veretennikov, Xuan Zhang, Y. A. Tikhonov, A. Hamdi, J. Hofmann, A. Filippi, A. Golubev, Tobias Stockmanns, V. Abramov, C. Hahn, A. Belias, K. Nowakowski, V. Serdyuk, M. Pelizä, Z. Tavukoglu, B. Ketzer, Jerzy Smyrski, J. Pütz, O. Malyshev, U. Kurilla, Konstantin Beloborodov, V. Chauhan, R. W. Novotny, A. Kantsyrev, P. Balanutsa, B. J. Liu, D. G. Ireland, Petr Gallus, G. D. Alexeev, D. Bonaventura, A. V. Stavinskiy, C. Motzko, K.-T. Brinkmann, H. Denizli, V. Crede, I. Zimmermann, E.K. Koshurnikov, Jize Zhao, R. Dzhygadlo, Kazem Azizi, A. Chlopik, Fabrizio Daví, V. Ferapontov, D. Y. Kirin, P. Wüstner, M. Fritsch, N. I. Zhuravlev, D. Rodríguez Piñeiro, Dan Pantea, A. Täschner, W. Eyrich, T. Held, W. Esmail, T. Triffterer, V. V. Tokmenin, K. Manasatitpong, W. Kühn, A. Khoukaz, A. Ali, Alexander Olshevskiy, S. Koch, J. Rieger, R. Hagdorn, S. Godre, V. Lucherini, T. Erlen, Herbert Koch, Y. K. Sun, Mariana Nanova, A. Verkheev, M. Marcisovsky, P. Fedorets, Yan Liang, Claude Amsler, M. Slunecka, S. Nakhoul, J. Müllers, Krisztian Peters, J. Oppotsch, A. Malige, N. Hüsken, B. Salisbury, G. Huang, S. Sun, F. Nerling, A. A. Piskun, F. H. Heinsius, G. Mazza, S. I. Manaenkov, O. Noll, A. T. Olgun, E. Antokhin, A. Gerasimov, S. Spataro, P. Salabura, D. Bumrungkoh, Q. Hu, Kamal K. Seth, D. P. Watts, S. Shimanski, V. Uzhinsky, M. Krebs, S. Bodenschatz, Karin Schönning, C. Yu, G. Perez-Andrade, G. Boca, Krzysztof Swientek, V. E. Blinov, P. De Remigis, C. J. Schmidt, Paolo Mengucci, Christoph Herold, F. Lisowski, E. A. Strokovsky, N. B. Skachkov, Y. Goncharenko, Harald Merkel, Lennart Isaksson, S. Maldaner, S. Pongampai, F. Khalid, W. Lauth, F. Feldbauer, G. Reicherz, Volker Metag, C. Mannweiler, M. Moritz, L. Montalto, Piotr Lebiedowicz, D. Prasuhn, A. Scholl, Michaela Thiel, R. Schmitz, S. Pflüger, J. Kannika, M. Albrecht, M. Volf, V.Kh. Dodokhov, P. Poznański, Marek Idzik, M. O. Distler, I. Shein, T. Wasem, J. Schwiening, T. Sefzick, Giovanni Lancioni, J. Tarasiuk, E. Ladygina, Hans-Georg Zaunick, A. E. Blinov, N. Wongprachanukul, W. Schäfer, S. Schadmand, G. Schepers, Yu. Yu. Lobanov, I. Augustin, Mathias Fink, D. Lehmann, P. Terlecki, P. Eugenio, Concettina Sfienti, S. Poslavskiy, M. Virius, S. Schlimme, C. Schwarz, Andreas Martin Heinz, Andrey Uzunian, B. Zwieglinski, M. Lattery, A. E. Yakutin, P.-E. Tegnér, H. Peng, J. Pereira-de-Lira, Ting Xiao, A.A. Efremov, James Ritman, L. Brück, Antonin Kveton, V. Mochalov, V. M. Abazov, S. Wolff, E. A. Kravchenko, E. Prencipe, F. E. Maas, R. Beck, Krzysztof Korcyl, Lorenzo Scalise, Gianangelo Bracco, L. Tomasek, Patrick Achenbach, A. Derevschikov, E. Vishnevsky, D. Melnychuk, M. Firlej, P. Srisawad, A. Dbeyssi, J. Petersen, I. Köseoglu, D. Miehling, M. Bölting, J. Regina, P. Wintz, J. Reher, W. Alkakhi, H. H. Leithoff, S. Bleser, S. Kegel, N. Er, S. Pankonin, Antoni Szczurek, D. Kazlou, M. Yu. Barabanov, Dirk Grunwald, L. Capozza, L. Linzen, D. Liu, V. Freudenreich, A. Ehret, C. Liu, Yupeng Yan, P. Gianotti, R. Dosdall, Ch. Schmidt, M. Steinen, Y. Zhou, A. Demekhin, A. Galoyan, M. Preston, Zhengtai Liu, T. Holtmann, Paweł Moskal, Mikhail Korzhik, A. Boukharov, D. Klostermann, S. Orfanitski, E. Pyata, P. P. Natali, G. Golovanov, M. Pesek, Ch. Hammann, C. Schnier, J. G. Messchendorp, P. Semenov, V. Rodin, Valentino Rigato, B. Kopf, Keval Gandhi, Daniel Duda, Andrea Bianconi, D. I. Glazier, A. Gillitzer, A. Akram, H. Flemming, M. Kümmel, M. Steinke, I. A. Kuyanov, N. Rathod, D. Calvo, D. Wölbing, R. Böhm, Ali Yilmaz, F. Schupp, Sean A Dobbs, J. Pochodzalla, U. Lynen, S. Chernichenko, B. Krusche, Felice Iazzi, Richard Wheadon, X. Y. Shen, L. Jokhovets, S.G. Pivovarov, R. Kappert, A. Lehmann, Ayut Limphirat, P. Kulessa, I. Lehmann, Andrea Lavagno, N. Kristi, T. Nasawad, A. Dolgolenko, M. Peskova, J. Płażek, Tomasz Fiutowski, L. Nogach, G. V. Fedotov, E. Luschevskaya, E. Maslova, R. Lalik, K. Khosonthongkee, C. Wenzel, M. Pfaffinger, Grzegorz Korcyl, O. Miklukho, A. N. Skachkova, Edward Lisowski, V. Jary, M. Kavatsyuk, M. Himmelreich, H. Deppe, A. G. Denig, A. Vasiliev, A. Derichs, J. Frech, A. Hayrapetyan, W. Zhu, Chinorat Kobdaj, P. Brand, E. Rosenthal, S. Belostotski, Ulrich Wiedner, A.S. Vodopianov, J. Kellers, U. Keskin, U. Thoma, R. Kliemt, A. Yu. Barnyakov, Bo Cederwall, K. Götzen, A. Meschanin, Michael Düren, Johann Marton, V. Chernetsky, Gianni Barucca, H. Loehner, Vaclav Vrba, M. Sachs, I. K. Keshk, Xi-Guang Cao, M. Traxler, S. Diehl, Andrew Levin, M.P. Bussa, S. Yerlikaya, Nicola Paone, A. Samartsev, P. Jiang, A. Fechtchenko, L. Schmitt, Michael Papenbrock, Bernd Voss, B. Hetz, Daniele Rinaldi, V. Moiseev, Magnus Wolke, V. Varentsov, M. Schmidt, N. Minaev, A. Balashoff, Mohammed Al-Turany, Andrzej Kupsc, P. Orsich, M. Steinacher, M. Finger, V. Panjushkin, H. Xu, M. Michałek, S. Bökelmann, S. Wronka, Andrey V. Izotov, M. Bukharova, G. Neue, R. Schubert, M. Tomasek, D. A. Morozov, S. Zimmermann, J. Grochowski, P. Wieczorek, S. Ryzhikov, M. Hoek, A. Gerhardt, H. Qi, Jens Hartmann, B. Seitz, S. Bukreeva, X. Zhou, G. Kesik, I. Prochazka, Mario Bragadireanu, K. Pysz, S. Coen, O. Korchak, K. Kalita, M. Küßner, O. Corell, T. Johansson, A. Ryazantsev, Y. Melnik, V. A. Matveev, S.A. Kononov, H. Orth, Hans Calén, M. Urban, G. Zhao, Witold Przygoda, T. Simantathammakul, J. Moron, J. Li, Oleg V. Missevitch, Frank Goldenbaum, Ajay Kumar Rai, M. Strickert, M. Böhm, Grzegorz Filo, M. Kunze, W. Ikegami Andersson, R. Klasen, S. Vestrick, Paul Alois Buhler, J. Lühning, J. Novy, Valery Dormenev, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Nuclear and High Energy Physics, hyperon: particle source, Hadron, Type (model theory), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, decay modes, Combinatorics, Tree (descriptive set theory), excited state: spectrum, 0103 physical sciences, ddc:530, structure, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, baryon: excited state, Spectrum (functional analysis), Hyperon, anti-p, Baryon, statistics, efficiency, Excited state, Production (computer science), acceptance
Abstract

The European physical journal / A 57(4), 149 (2021). doi:10.1140/epja/s10050-021-00444-5, Published by Springer, Heidelberg

Published
2021
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41. Dynamical properties of baryons

Author

Andrea Bianconi, S. Pacetti, Egle Tomasi-Gustafsson, Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Particle physics, Physics and Astronomy (miscellaneous), General Mathematics, review, Virtual particle, Electron, electron positron: annihilation, 01 natural sciences, charge distribution, hadron: structure, electron: accelerator, cross section: annihilation, Cross section (physics), 0103 physical sciences, Computer Science (miscellaneous), QA1-939, 010306 general physics, Physics, form factor: ratio, polarization, Annihilation, form factor: magnetic, 010308 nuclear & particles physics, Scattering, scattering, Form factors, Charge density, Annihilation and scattering reactions, Polarization (waves), form factor: electromagnetic, coherence, Baryon, baryon, Hadron structure, Chemistry (miscellaneous), kinematics, p: form factor, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Mathematics
Abstract

The internal structure of composite particles is conveniently described in terms of form factors (FFs)—these are experimentally accessible in annihilation and scattering of elementary reactions, and are theoretically calculable by all models that describe the properties of particles. FFs depend only on one kinematical variable, q2. This is the four-momentum transferred by the virtual photon that carries the interaction. Important developments in accelerator and detector techniques have brought impressive advances, both by extending the kinematical region and by reaching a higher precision. A critical review on the underlying methods and findings in polarized and unpolarized experiments is presented. The unique role played by polarization in determining the ratio of electric to magnetic form factors in the space-like region, and the extraction of individual form factors in the whole kinematical region, are described. Recent results at electron accelerators and electron–positron colliders confirm the existence of periodical structure in the annihilation cross section. We suggest a global framework which describes the dynamical structure of charge distribution in baryons, in order to build a coherent view of the creation and annihilation of baryonic matter.

Published
2021
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42. PANDA Phase One: PANDA collaboration

Author

R. Klasen, S. Vestrick, Grzegorz Filo, S. Diehl, M. Kunze, W. Ikegami Andersson, A. V. Stavinskiy, Yupeng Yan, Felice Iazzi, D. Rodríguez Piñeiro, J. Müllers, Andrew Levin, Paul Alois Buhler, J. Lühning, J. Novy, Valery Dormenev, James Ritman, Piotr Lebiedowicz, L. Montalto, M. Küßner, A. Scholl, Frank Goldenbaum, Ali Yilmaz, Yan Liang, W. Esmail, M.P. Bussa, A. Ali, L. Jokhovets, S.G. Pivovarov, D. Bonaventura, A. Verkheev, S. Rimjaem, M. Preston, A. T. Olgun, Konstantin Beloborodov, P. Fedorets, A. Hamdi, M. Volf, S. Yerlikaya, S. Nakhoul, J. Kannika, O. Corell, A. Vasiliev, G. Mazza, E. Antokhin, A. Gerasimov, Egle Tomasi-Gustafsson, J. Hofmann, R. Karabowicz, V.Kh. Dodokhov, A. E. Blinov, P.-E. Tegnér, Andrey Uzunian, S. Wolff, M. Steinen, L. Linzen, Y. Zhou, F. H. Heinsius, Zhengtai Liu, P. De Remigis, C. J. Schmidt, I. Lehmann, H. Denizli, H. Deppe, Ajay Kumar Rai, T. Johansson, T. Holtmann, A. G. Denig, V. Panjushkin, J. Frech, A. Hayrapetyan, W. Zhu, L. Nogach, E. Vishnevsky, D. Melnychuk, Q. Hu, I. Köseoglu, Andrea Bianconi, J. Pereira-de-Lira, A. Derevschikov, A. Belias, O. Malyshev, D. Miehling, Nicola Paone, K. Pysz, A. Ryazantsev, D. I. Glazier, G. Reicherz, R. Hagdorn, M. Strickert, M. Böhm, Chinorat Kobdaj, P. Brand, Vladimir Blinov, P. Wüstner, X. Y. Shen, Paolo Mengucci, Christoph Herold, M. Pelizäus, G. V. Fedotov, T. Nasawad, A. Dolgolenko, N. B. Skachkov, S. Pongampai, S. Coen, Y. Melnik, V. A. Matveev, U. Kurilla, V. Jary, B. Zwieglinski, F. Khalid, A. Gillitzer, D. Calvo, Andreas Martin Heinz, M. Kavatsyuk, Mariana Nanova, S. Belostotski, K. Nowakowski, Claude Amsler, T. Erlen, K. Kalita, M. Domagala, A. Derichs, Ulrich Wiedner, E. Prencipe, L. Brück, R. Schmitz, Antonin Kveton, V. Mochalov, A.S. Vodopianov, J. Kellers, J. Rieger, G. Huang, N. Wongprachanukul, Bo Cederwall, K. Götzen, A. N. Skachkova, Edward Lisowski, J. Pütz, U. Müller, C. Motzko, K.-T. Brinkmann, S.A. Kononov, Dirk Grunwald, G. Neue, U. Thoma, R. Lalik, A. Kantsyrev, S. Sun, M. Virius, B. Salisbury, J. Oppotsch, Jize Zhao, R. Dzhygadlo, T. Held, F. Nerling, G. D. Alexeev, M. Bölting, A. Boukharov, G. Golovanov, I. Zimmermann, N. Er, A. Malige, S. Godre, Ting Xiao, M. Wojciechowski, Ch. Schmidt, T. Simantathammakul, B. Seitz, P. Balanutsa, B. J. Liu, V. Crede, M. Krebs, E. Rosenthal, Y. K. Sun, D. G. Ireland, W. Kühn, V. Abramov, Z. Tavukoglu, Mikhail Korzhik, A. Kripko, S. Spataro, D. Bumrungkoh, V. M. Abazov, R. Schubert, H. Flemming, Vaclav Vrba, S. I. Manaenkov, S. Kegel, A. Lehmann, U. Keskin, Hans-Georg Zaunick, R. Kliemt, V. Uzhinsky, Karin Schönning, X. Zhou, R. Böhm, S. Maldaner, J. Moron, D. P. Watts, E.K. Koshurnikov, M. Slunecka, P. Poznański, M. Firlej, P. Srisawad, A. Yu. Barnyakov, D. Kazlou, M. Yu. Barabanov, J. Płażek, V. Chauhan, R. W. Novotny, S. Schlimme, C. Schwarz, Y. Goncharenko, Lennart Isaksson, P. Eugenio, Kamal K. Seth, Concettina Sfienti, Harald Merkel, H. Xu, A. Meschanin, Marek Idzik, Mario Bragadireanu, Kazem Azizi, M. Lattery, C. Yu, G. Perez-Andrade, G. Boca, C. Liu, A. Chlopik, Johann Marton, Jens Hartmann, A. Samartsev, M. O. Distler, Dan Pantea, W. Eyrich, P. Gianotti, J. Li, E. Ladygina, Michael Düren, M. Albrecht, M. Tomasek, J. Regina, Michaela Thiel, I. Shein, L. Capozza, V. Chernetsky, Y. A. Tikhonov, Oleg V. Missevitch, V. Lucherini, Lorenzo Scalise, Fabrizio Daví, J. Petersen, F. E. Maas, A. Filippi, Gianni Barucca, T. Wasem, J. Reher, J. Schwiening, P. Wintz, O. Korchak, M. Marcisovsky, Volker Metag, S. Zimmermann, N. Hüsken, S. Pankonin, P. Jiang, Antoni Szczurek, C. Schnier, H. Orth, S. Bukreeva, H. Loehner, S. Orfanitski, D. Lehmann, C. Mannweiler, V. Ferapontov, D. Y. Kirin, M. Moritz, C. Hahn, D. A. Morozov, J. Grochowski, A. A. Piskun, Hans Calén, Christoph Hanhart, S. Bodenschatz, J. Tarasiuk, Christian S. Fischer, M. Urban, G. Zhao, T. Sefzick, A. Demekhin, P. Wieczorek, Giovanni Lancioni, Daniel Duda, M. Hoek, A. Akram, S. Ryzhikov, Yu. Yu. Lobanov, E. A. Strokovsky, A. Galoyan, F. Feldbauer, S. Shimanski, A.A. Efremov, Paweł Moskal, H. Peng, G. Kesik, S. Schadmand, B. Kopf, G. Schepers, B. Krusche, J. G. Messchendorp, V. V. Tokmenin, K. Manasatitpong, A. Dbeyssi, M. Fritsch, Witold Przygoda, S. Poslavskiy, Valentino Rigato, A. Khoukaz, M. Kümmel, D. Klostermann, S. Koch, E. A. Kravchenko, M. Sachs, Ayut Limphirat, L. Tomasek, I. K. Keshk, D. Liu, P. P. Natali, A. Gerhardt, H. Qi, I. A. Kuyanov, Patrick Achenbach, Alexander Olshevskiy, W. Alkakhi, N. Kristi, H. H. Leithoff, N. I. Zhuravlev, P. Semenov, V. Rodin, Keval Gandhi, E. Maslova, Xi-Guang Cao, M. Traxler, Herbert Koch, A. Täschner, Grzegorz Korcyl, Krisztian Peters, P. Kulessa, Sinead M. Ryan, F. Schupp, Sean A Dobbs, J. Pochodzalla, M. Himmelreich, S. Chernichenko, O. Noll, T. Triffterer, F. Lisowski, P. Salabura, Krzysztof Swientek, Pawel Marciniewski, D. Veretennikov, W. Lauth, Xuan Zhang, I. Prochazka, D. Prasuhn, Johann Haidenbauer, S. Pflüger, W. Schäfer, A. Golubev, Tobias Stockmanns, S. Bleser, V. Serdyuk, M. Michałek, B. Ketzer, Jerzy Smyrski, S. Bökelmann, V. Freudenreich, A. Ehret, S. Wronka, R. Kappert, Andrey V. Izotov, M. Bukharova, E. Luschevskaya, K. Khosonthongkee, C. Wenzel, M. Pfaffinger, E. Pyata, Ch. Hammann, M. Steinke, A. Fechtchenko, L. Schmitt, Michael Papenbrock, N. Rathod, D. Wölbing, Richard Wheadon, U. Lynen, Andrea Lavagno, M.F.M. Lutz, Bernd Voss, B. Hetz, Daniele Rinaldi, Tomasz Fiutowski, V. Moiseev, Magnus Wolke, V. Varentsov, M. Schmidt, N. Minaev, A. Balashoff, Mohammed Al-Turany, Andrzej Kupsc, P. Orsich, M. Steinacher, M. Finger, I. Augustin, Mathias Fink, P. Terlecki, A. E. Yakutin, R. Beck, Krzysztof Korcyl, Gianangelo Bracco, R. Dosdall, and O. Miklukho

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Luminosity (scattering theory), 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Physics beyond the Standard Model, Hadron, Detector, Strong interaction, 01 natural sciences, Antiproton, 0103 physical sciences, Facility for Antiproton and Ion Research, 010306 general physics, Nuclear Experiment, Storage ring
Abstract

The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or $$\overline{\mathrm{P}}$$ P ¯ ANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton–nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper.

Published
2021

43. Measurement of the proton spin structure at long distances

Author

P. Eugenio, J. Brock, N. Dashyan, I. Bedlinskiy, S. Choi, P. Nadel-Turonski, A. Hobart, M. Defurne, S. E. Kuhn, Latifa Elouadrhiri, P. Chatagnon, M. Ripani, C. D. Keith, D. Bulumulla, Aditya R. Khanal, S. Adhikari, B. McKinnon, T. Holmstrom, V. Mokeev, G. V. Fedotov, H. S. Jo, L. Guo, Alessandro Rizzo, Andrea Bianconi, L. Barion, M. Mirazita, K. Livingston, M. Hattawy, N. Markov, G. Rosner, Simon Širca, S. Fegan, Y. Ghandilyan, Jie Zhang, P. Bosted, Michael Paolone, C. Carlin, M. Guidal, M. L. Seely, E. Pasyuk, D. P. Watts, F. Bossu, Laura Clark, S. Niccolai, N. Guler, M. Holtrop, B. Yale, R. A. Schumacher, P. Rossi, W. Phelps, V. Mascagna, S. Joosten, Axel Schmidt, Alexandre Deur, Luciano Pappalardo, Nikolaos Sparveris, V. Crede, I. I. Strakovsky, W. Kim, Fatiha Benmokhtar, M. Ehrhart, D. I. Glazier, V. P. Kubarovsky, T. A. Forest, O. Pogorelko, Z. W. Zhao, J. Rowley, S. Stepanyan, A. I. Ostrovidov, K. Park, Krishna Neupane, R. De Vita, A. El Alaoui, Y. Ilieva, Nicholas Zachariou, D. G. Ireland, C. W. Kim, H. Avakian, C. Mullen, W. K. Brooks, A. Kripko, Andrea Celentano, Volker D. Burkert, A. S. Biselli, J. C. Carvajal, V. Sulkosky, H. Atac, Karl Slifer, M. Leali, F. Sabatié, L. Venturelli, Y. G. Sharabian, X. Zheng, M. Bondì, H. Voskanyan, P. Lenisa, W. J. Briscoe, I. J. D. MacGregor, M. Contalbrigo, S. K. Phillips, T. Mineeva, T. B. Hayward, Friedrich Klein, Brian Raue, J. Poudel, N. Tyler, C. Djalali, G. Ciullo, M. Osipenko, Y. Prok, D. S. Carman, X. Wei, K. A. Griffioen, E. Voutier, Dustin Keller, S. Strauch, L. Lanza, R. W. Gothe, Michael Wood, T. Chetry, K. Hafidi, R. Dupre, M. Battaglieri, Gerard Gilfoyle, E. L. Isupov, V. A. Drozdov, S. Boiarinov, H. Kang, U. Shrestha, F.-X. Girod, K. P. Adhikari, H. Hakobyan, J. Ritman, S. Diehl, C. Salgado, R. G. Fersch, M. Ungaro, E. Long, J. P. Chen, D. Heddle, P. L. Cole, D. G. Meekins, A. D'Angelo, K. Hicks, L. El Fassi, K. Joo, M. Khandaker, M. J. Amaryan, A. Filippi, K. L. Giovanetti, Larry Weinstein, L. Marsicano, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS

Subjects
polarizabilities, Photon, Proton, High Energy Physics::Lattice, Nuclear Theory, General Physics and Astronomy, polarized target, polarized beam, 01 natural sciences, 7. Clean energy, 010305 fluids & plasmas, High Energy Physics - Experiment, Theoretical Nuclear Physics, Experimental Nuclear Physics, High Energy Physics - Experiment (hep-ex), effective field theory, Economica, Proton spin crisis, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Experimental particle Physics, order, Nuclear Experiment (nucl-ex), Nuclear Experiment, Spin-½, Quantum chromodynamics, Physics, Settore FIS/04, nucleon, virtual compton-scattering, chiral perturbation-theory, sum-rule, moments, evolution, sum rule, kinematics, Quantum electrodynamics, nuclear matter, Nucleon, nucleon: structure, Strong interaction, FOS: Physical sciences, Socio-culturale, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], p: spin, PE2_2, momentum transfer: low, PE2_1, CLAS, 0103 physical sciences, quantum chromodynamics, ddc:530, 010306 general physics, PE2_3, quark gluon, Coupling constant, nuclear force, scattering, Ambientale, Physics::Accelerator Physics, nucleon: spin, High Energy Physics::Experiment, experimental results
Abstract

Measuring the spin structure of protons and neutrons tests our understanding of how they arise from quarks and gluons, the fundamental building blocks of nuclear matter. At long distances the coupling constant of the strong interaction becomes large, requiring non-perturbative methods to calculate quantum chromodynamics processes, such as lattice gauge theory or effective field theories. Here we report proton spin structure measurements from scattering a polarized electron beam off polarized protons. The spin-dependent cross-sections were measured at large distances, corresponding to the region of low momentum transfer squared between 0.012 and 1.0 GeV$^2$. This kinematic range provides unique tests of chiral effective field theory predictions. Our results show that a complete description of the nucleon spin remains elusive, and call for further theoretical works, e.g. in lattice quantum chromodynamics. Finally, our data extrapolated to the photon point agree with the Gerasimov-Drell-Hearn sum rule, a fundamental prediction of quantum field theory that relates the anomalous magnetic moment of the proton to its integrated spin-dependent cross-sections., Published version. 10 pages, 5 figures. 20 pages of supplementary material (data tables and a figure)

Published
2021
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44. New fit of time-like proton electromagnetic form factors from $e^+e^-$ colliders

Author

Egle Tomasi-Gustafsson, Andrea Bianconi, S. Pacetti, Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Particle physics, Proton, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], Nuclear Theory, media_common.quotation_subject, Structure (category theory), Hadronic Physics and QCD, FOS: Physical sciences, Timelike, Timelike, Form factor, Proton, 01 natural sciences, Asymmetry, Moduli, cross section: annihilation, Nuclear Theory (nucl-th), Cross section (physics), High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, structure, moduli, 010306 general physics, Nuclear theory, media_common, Physics, form factor: ratio, Annihilation, BES, 010308 nuclear & particles physics, Form factor (quantum field theory), oscillation, Form factor, form factor: electromagnetic, coherence, High Energy Physics - Phenomenology, p: form factor, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], BaBar, asymmetry
Abstract

The data on the proton form factors in the time-like region from the BaBar, BESIII and CMD-3 Collaborations are examined to have coherent pieces of information on the proton structure. Oscillations in the annihilation cross section, previously observed, are determined with better precision. The moduli of the individual form factors, determined for the first time, their ratio and the angular asymmetry of the annihilation reaction $e^+e^-\to\bar p p$ are discussed. Fiits of the available data on the cross section, the effective form factor, and the form factor ratio, allow to propose a description of the electric and magnetic time-like form factors from the threshold up to the highest momenta., 20 pages, 7 figures

Published
2020
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45. Photoproduction of η mesons off the proton for 1.2<Eγ<4.7GeV using CLAS at Jefferson Laboratory

Author

I. Illari, R. A. Schumacher, U. Shrestha, M. Leali, S. Adhikari, B. McKinnon, C. A. Meyer, E. Munevar, P. Chatagnon, B. S. Ishkhanov, Aditya R. Khanal, G. V. Fedotov, P. Lenisa, J. Ritman, S. Stepanyan, N. Dashyan, D. P. Watts, Andrea Bianconi, M. Ungaro, K. P. Adhikari, A. El Alaoui, I. I. Strakovsky, G. Rosner, T. Chetry, A. Deur, C. W. Kim, Laura Clark, W. Phelps, M. Battaglieri, Nicholas Zachariou, J. C. Carvajal, Alexander Schmidt, M. J. Amaryan, William Brooks, Yordanka Ilieva, T. B. Hayward, V. Mascagna, B. A. Clary, E. L. Isupov, Y. G. Sharabian, H. Voskanyan, Friedrich Klein, W. J. Briscoe, P. Eugenio, S. Boiarinov, Brian Raue, G. Angelini, L. Barion, K. Joo, M. Guidal, Michael Paolone, Z. W. Zhao, F. X. Girod, F. Bossu, R. Cruz-Torres, E. Golovatch, M. Holtrop, R. Dupre, S. Strauch, Hovanes Egiyan, Maxime Defurne, K. A. Griffioen, Dustin Keller, C. Munoz Camacho, H. Hakobyan, Y. Prok, H. S. Jo, M. Hattawy, Michael Wood, K. Hafidi, D. G. Ireland, Luciano Pappalardo, V. Crede, A. Kim, D. I. Glazier, G. Ciullo, D. S. Carman, F. Sabatié, T. Hu, R. Paremuzyan, R. De Vita, D. Marchand, D. Protopopescu, Eugene Pasyuk, X. Wei, L. Venturelli, S. Diehl, Fatiha Benmokhtar, O. Soto, C. Salgado, E. Voutier, L. Lanza, Nicholas M. Harrison, Gerard Gilfoyle, A. Filippi, A. Movsisyan, J. W. Price, D. Sokhan, V. P. Kubarovsky, I. Bedlinskiy, M. Khandaker, M. Khachatryan, Nikolaos Sparveris, Z. E. Meziani, K. Wei, S. Niccolai, K. Livingston, N. Markov, Iu. Skorodumina, N. Tyler, C. Djalali, J. A. Tan, V. I. Mokeev, D. Heddle, Jie Zhang, G. Gavalian, D. G. Jenkins, R. Fersch, M. Ehrhart, M. Ripani, O. Pogorelko, P. L. Cole, J. Rowley, Tim O'Connell, A. I. Ostrovidov, Michael Dugger, T. Mineeva, P. Nadel-Turonski, H. Atac, A. S. Biselli, A. D'Angelo, L. Guo, Sylvester Joosten, Alessandro Rizzo, G. Asryan, L. El Fassi, C. Ayerbe Gayoso, M. E. McCracken, A. Hobart, C. Hanretty, W. Kim, G. Niculescu, P. Stoler, M. Osipenko, I. J. D. MacGregor, K. Hicks, M. Contalbrigo, J. Poudel, Z. Akbar, A. Celentano, and R. W. Gothe

Subjects
Physics, Particle physics, Range (particle radiation), Photon, Proton, Meson, 010308 nuclear & particles physics, Sigma, Photon energy, 01 natural sciences, 7. Clean energy, Resonance (particle physics), 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon
Abstract

Photoproduction cross sections are reported for the reaction $\gamma p\to p\eta$ using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The $\eta$ mesons are detected in their dominant charged decay mode, $\eta\to \pi^+\pi^-\pi^0$, and results on differential cross sections are presented for incident photon energies between 1.2 and 4.7 GeV. These new $\eta$ photoproduction data are consistent with earlier CLAS results but extend the energy range beyond the nucleon resonance region into the Regge regime. The normalized angular distributions are compared with the experimental results from several other experiments, and with predictions of $\eta$ MAID\,2018 and the latest solution of the Bonn-Gatchina coupled-channel analysis. Differential cross sections $d\sigma/dt$ are presented for incident photon energies $E_\gamma > 2.9$ GeV ($W > 2.5$ GeV), and compared with predictions which are based on Regge trajectories exchange in the $t$-channel (Regge models). The data confirm the expected dominance of $\rho$, $\omega$ vector-meson exchange in an analysis by the Joint Physics Analysis Center.

Published
2020
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46. Extraction of beam-spin asymmetries from the hard exclusive π+ channel off protons in a wide range of kinematics

Author

Y. G. Sharabian, K. Tezgin, S. E. Kuhn, M. Hattawy, S. Adhikari, M. Khachatryan, M. J. Amaryan, N. Tyler, P. Lenisa, C. Dilks, J. A. Tan, C. W. Kim, H. Avakian, B. McKinnon, Maxime Defurne, Laura Clark, K. A. Griffioen, Chaden Djalali, D. Bulumulla, T. Mineeva, L. Guo, G. Angelini, D. I. Glazier, B. S. Ishkhanov, S. Strauch, Aditya R. Khanal, F. X. Girod, T. B. Hayward, M. Guidal, D. P. Watts, K. L. Giovanetti, P. L. Cole, E. L. Isupov, E. Golovatch, G. Asryan, L. Lanza, R. De Vita, Alessandro Rizzo, Z. W. Zhao, V. Crede, R. Dupre, H. Voskanyan, Andrea Bianconi, N. Markov, Brian Raue, Y. Ghandilyan, S. Boiarinov, A. D'Angelo, M. Mirazita, M. Ehrhart, W. Phelps, W. J. Briscoe, A. Filippi, M. Holtrop, Victor Mokeev, U. Shrestha, L. El Fassi, H. Atac, P. Nadel-Turonski, M. Khandaker, Luciano Pappalardo, P. Eugenio, J. W. Price, O. Pogorelko, I. J. D. MacGregor, T. Chetry, M. Osipenko, J. Rowley, M. Ripani, Fatiha Benmokhtar, H. Hakobyan, O. Soto, M. Battaglieri, S. Diehl, Paolo Rossi, K. Park, Michael Paolone, A. Celentano, R. W. Gothe, D. Heddle, F. Bossu, D. G. Ireland, Hovanes Egiyan, C. Munoz Camacho, W. Kim, Axel Schmidt, G. Niculescu, P. Stoler, Volker D. Burkert, M. Contalbrigo, A. S. Biselli, M. Ungaro, I. I. Strakovsky, K. Hicks, A. Deur, Nicholas M. Harrison, Gerard Gilfoyle, D. Marchand, V. Mascagna, Eugene Pasyuk, W. K. Brooks, D. G. Jenkins, S. Joosten, L. Marsicano, V. P. Kubarovsky, K. P. Adhikari, M. Leali, D. Riser, Z. E. Meziani, Y. Prok, F. Sabatié, I. Bedlinskiy, P. Kroll, K. Joo, Dustin Keller, Michael Wood, A. Kim, K. Livingston, Jie Zhang, H. S. Jo, C. Salgado, A. El Alaoui, Y. Ilieva, P. Chatagnon, Nicholas Zachariou, J. C. Carvajal, K. Semenov-Tian-Shansky, N. Dashyan, E. Voutier, L. Venturelli, L. Barion, R. A. Schumacher, G. Ciullo, D. S. Carman, Nikos Sparveris, X. Wei, T. A. Forest, S. Stepanyan, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS

Subjects
Particle physics, generalized parton distribution, Partons, Nucleons, Compton Scattering, media_common.quotation_subject, General Physics and Astronomy, parton: distribution function, Socio-culturale, Parton, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, Resonance (particle physics), Asymmetry, High Energy Physics - Experiment, Pion, PE2_2, PE2_1, CLAS, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], 010306 general physics, Nuclear Experiment, PE2_3, Spin-½, media_common, Physics, Settore FIS/04, electroproduction, moment, Moment (mathematics), distribution amplitude, High Energy Physics - Phenomenology, Amplitude, kinematics, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Elementary Particles and Fields, High Energy Physics::Experiment, Center of mass, asymmetry, experimental results
Abstract

We have measured beam-spin asymmetries to extract the \ud sin\ud ϕ\ud moment \ud A\ud sin\ud ϕ\ud L\ud U\ud from the hard exclusive \ud →\ud e\ud p\ud →\ud e\ud ′\ud n\ud π\ud +\ud reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center of mass. The \ud A\ud sin\ud ϕ\ud L\ud U\ud moment has been measured up to \ud 6.6\ud \ud \ud GeV\ud 2\ud in \ud −\ud t\ud , covering the kinematic regimes of generalized parton distributions (GPD) and baryon-to-meson transition distribution amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found \ud A\ud sin\ud ϕ\ud L\ud U\ud to be negative, while a sign change was observed near 90° in the center of mass. The unique results presented in this Letter will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.

Published
2020
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47. First measurement of direct photoproduction of the a2(1320)0 meson on the proton

Author

J. Rowley, A. I. Ostrovidov, Volker D. Burkert, A. S. Biselli, W. Phelps, K. A. Griffioen, V. Mascagna, N. Markov, M. E. McCracken, A. Hobart, Carlos A. Salgado, A. Filippi, A. Pilloni, Frank Klein, Dustin Keller, P. Eugenio, L. Marsicano, Sylvester Joosten, Maxime Defurne, M. Khandaker, M. Khachatryan, M. Osipenko, Pawel Nadel-Turonski, Michael Paolone, Alexander Schmidt, D. I. Glazier, D. Bulumulla, E. Munevar, B. S. Ishkhanov, Aditya R. Khanal, Nikolaos Sparveris, M. Ungaro, K. Hafidi, F. Bossu, M. Guidal, G. Niculescu, L. Lanza, D. G. Jenkins, I. J. D. MacGregor, R. De Vita, M. Leali, Laura Clark, M. J. Amaryan, Andrea Bianconi, C. W. Kim, W. Kim, W. Gohn, F. X. Girod, N. Tyler, C. Djalali, J. A. Tan, P. Chatagnon, G. V. Fedotov, H. Voskanyan, A. D'Angelo, T. Chetry, I. Bedlinskiy, L. Elouadrhiri, M. Holtrop, F. Hauenstein, W. J. Briscoe, E. Pasyuk, S. Strauch, K. Joo, H. Atac, D. P. Watts, H. Egiyan, G. Angelini, L. El Fassi, I. I. Strakovsky, R. Dupre, M. Battaglieri, F. Sabatié, Luciano Pappalardo, D. Heddle, A. Deur, M. Ripani, G. Gavalian, V. Mokeev, D. Marchand, V. Lucherini, V. P. Kubarovsky, Michael Dugger, Fatiha Benmokhtar, Krishna Neupane, R. G. Fersch, O. Pogorelko, O. Soto, S. Niccolai, Vincent Mathieu, P. L. Cole, Z. W. Zhao, Alessandro Rizzo, E. Golovatch, P. Lenisa, K. Hicks, M. Ehrhart, S. Adhikari, T. B. Hayward, J. Zhang, M. Hattawy, J. W. Price, N. Dashyan, Yordanka Ilieva, L. Barion, G. Rosner, William Brooks, G. Ciullo, Y. Prok, L. Venturelli, D. S. Carman, R. A. Schumacher, A. El Alaoui, X. Wei, Nicholas Zachariou, J. C. Carvajal, S. Stepanyan, E. Voutier, A. Movsisyan, Adam P. Szczepaniak, D. Sokan, Z. E. Meziani, K. Livingston, K. P. Adhikari, H. Hakobyan, H. S. Jo, A. Kim, J. Ritman, S. Diehl, D. G. Ireland, V. Crede, O. Cortes, E. L. Isupov, R. Paremuzyan, S. Boiarinov, R. Cruz-Torres, Nicholas M. Harrison, U. Shrestha, M. Contalbrigo, C. Munoz Camacho, M. H. Wood, B. McKinnon, A. Celentano, R. W. Gothe, M. Mirazita, and N. Gevorgyan

Subjects
Physics, Meson, 010308 nuclear & particles physics, Partial wave analysis, Hadron, Sigma, Photon energy, 01 natural sciences, Nuclear physics, Amplitude, 0103 physical sciences, Invariant mass, Nuclear Experiment, 010306 general physics, Phenomenology (particle physics)
Abstract

We present the first measurement of the exclusive reaction $\gamma p \rightarrow a_2(1320)^0 \, p$ in the photon energy range $3.5$-$5.5$ GeV and four-momentum transfer squared $0.2

Published
2020
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48. 12C(e,e'pN) measurements of short range correlations in the tensor-to-scalar interaction transition region

Author

M. J. Amaryan, P. Lenisa, Jie Zhang, A. Beck, L. Marsicano, T. B. Hayward, U. Shrestha, Larry Weinstein, S. Strauch, Maxime Defurne, K. A. Griffioen, D. P. Watts, Friedrich Klein, R. Paremuzyan, Brian Raue, O. Pogorelko, J. Rowley, A. I. Ostrovidov, R. A. Schumacher, F. X. Girod, M. Duer, A. Denniston, E. Golovatch, R. Dupre, Nicholas M. Harrison, R. De Vita, I. I. Strakovsky, P. Eugenio, A. Deur, W. K. Brooks, A. Filippi, D. Sokhan, B. A. Clary, D. Protopopescu, Volker D. Burkert, A. S. Biselli, L. Lanza, M. Khandaker, N. Tyler, C. Djalali, E. Voutier, Michael Paolone, Y. G. Sharabian, X. Zheng, H. Atac, J. A. Tan, Y. Prok, D. S. Carman, I. Bedlinskiy, W. Phelps, V. Lucherini, M. Battaglieri, A. El Alaoui, Y. Ilieva, E. L. Isupov, Nicholas Zachariou, X. Wei, S. Mey-Tal Beck, S. Boiarinov, Hovanes Egiyan, F. Hauenstein, C. Munoz Camacho, J. W. Price, Taofeng Wang, Fatiha Benmokhtar, M. Khachatryan, Nikolaos Sparveris, N. Markov, A. Movsisyan, R. Cruz-Torres, T. A. Forest, O. Soto, D. Heddle, M. Ungaro, K. P. Adhikari, Douglas Higinbotham, Latifa Elouadrhiri, D. Marchand, P. Nadel-Turonski, S. Adhikari, B. McKinnon, M. Ripani, A. Kim, S. Stepanyan, I. Korover, M. Hattawy, M. Guidal, B. Mustapha, Z. W. Zhao, T. Mineeva, Or Hen, H. Hakobyan, M. Mirazita, J. Ritman, L. Barion, J.R. Pybus, M. Holtrop, S. Diehl, R. G. Fersch, C. Salgado, K. Joo, Luciano Pappalardo, T. Chetry, E.P. Segarra, H. S. Jo, D. G. Jenkins, M. Leali, Eugene Pasyuk, P. L. Cole, M. Ehrhart, G. Rosner, P. Chatagnon, A. D'Angelo, L. El Fassi, V. P. Kubarovsky, L. Venturelli, Krishna Neupane, C. W. Kim, H. Voskanyan, W. J. Briscoe, Dustin Keller, E. Piasetzky, D. Bulumulla, Michael Wood, K. Hafidi, Aditya R. Khanal, Andrea Bianconi, G. Niculescu, Alexander Schmidt, G. Gavalian, M. Osipenko, I. J. D. MacGregor, F. Sabatié, D. G. Ireland, V. Crede, M. Contalbrigo, Laura Clark, G. Angelini, K. Hicks, A. Celentano, R. W. Gothe, Alessandro Rizzo, V. Mascagna, S. Joosten, K. Livingston, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and The Clas Collaboration

Subjects
Nuclear and High Energy Physics, Nuclear Theory, dependence, CLAS, dynamics, isospin, energy, system, Astronomy & Astrophysics, Physics, QC1-999, Scalar (mathematics), FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Astrophysics, 01 natural sciences, Nuclear Theory (nucl-th), Momentum, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, ddc:530, Tensor, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics, Nuclear theory, [PHYS]Physics [physics], Range (particle radiation), 010308 nuclear & particles physics, Settore FIS/04, Nuclear interaction, High Energy Physics - Phenomenology, Astronomy &amp, Atomic physics, Nucleon
Abstract

High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the $^{12}$C$(e,e'p)$ and $^{12}$C$(e,e'pN)$ reactions (where $N$ is either $n$ or $p$), at high-$Q^2$ and $x_B>1.1$. The data span a missing-momentum range of 300--1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon ($NN$) interaction models. This agreement suggests that the measured high missing-momentum protons up to $1000$ MeV/c predominantly belong to short-ranged correlated (SRC) pairs. The measured $^{12}$C$(e,e'pN)$ / $^{12}$C$(e,e'p)$ and $^{12}$C$(e,e'pp)$ / $^{12}$C$(e,e'pn)$ cross-section ratios are consistent with a decrease in the fraction of proton-neutron SRC pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum. This confirms the transition from an isospin-dependent tensor $NN$ interaction at $\sim 400$ MeV/c to an isospin-independent scalar interaction at high-momentum around $\sim 800$ MeV/c as predicted by theoretical calculation., Accepted for publication in Physics Letters B. 7 pages, 3 figures, and online supplementary materials

Published
2021
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49. Beam–target helicity asymmetry $E$ in $K^+$ $\Sigma^-$ photoproduction on the neutron

Author

R. De Vita, D. Marchand, H. Atac, H. S. Jo, A. Filippi, L. Marsicano, N. K. Walford, O. Soto, M. Khandaker, I. J. D. MacGregor, K. Hicks, W. Phelps, R. A. Schumacher, Michael Paolone, H. Hakobyan, W. Kim, G. Charles, F. Bossu, H. Lu, S. Joosten, J. W. Price, S. Diehl, C. Salgado, William Brooks, L. Venturelli, D. Heddle, V. P. Kubarovsky, I. Bedlinskiy, Z. E. Meziani, V. Mascagna, A. Celentano, R. W. Gothe, N. Markov, Alessandro Rizzo, W. Gohn, G. Asryan, Axel Schmidt, Dustin Keller, M. Ungaro, M. Guidal, M. Contalbrigo, M. Osipenko, Z. W. Zhao, Fatiha Benmokhtar, E. L. Isupov, Y. Prok, J. Poudel, O. Pogorelko, A. I. Ostrovidov, K. Park, M. J. Amaryan, Michael Wood, K. Hafidi, M. Holtrop, M. Ehrhart, C.D. Bass, V. A. Nikonov, A. D'Angelo, D. G. Jenkins, D. G. Ireland, G. Rosner, S. Boiarinov, E. Golovatch, P. Eugenio, K. Livingston, Luciano Pappalardo, K. Joo, M. Leali, Jie Zhang, T. Kageya, Volker D. Burkert, Y. Ghandilyan, A. S. Biselli, C. W. Kim, G. Gavalian, U. Shrestha, F.-X. Girod, Gerard Gilfoyle, M. Ripani, R. G. Fersch, H. Voskanyan, A. El Alaoui, G. Angelini, Nicholas Zachariou, J. C. Carvajal, W. J. Briscoe, P. L. Cole, T. Chetry, N. Gevorgyan, D. Ho, I. I. Strakovsky, A. M. Sandorfi, A. Deur, Victor Mokeev, D. Sokhan, T. R. O'Connell, Chaden Djalali, P. Nadel Turonski, T. Mineeva, M. Bashkanov, S. Adhikari, D. Bulumulla, E. Munevar, B. McKinnon, B. S. Ishkhanov, Aditya R. Khanal, Andrea Bianconi, I. Zonta, X. Wei, P. Peng, Hovanes Egiyan, C. Munoz Camacho, P. Lenisa, M. Hattawy, J. A. Fleming, Friedrich Klein, Brian Raue, Andrew Puckett, E. Voutier, Martin K. Mayer, M. Khachatryan, K. A. Griffioen, Nikolaos Sparveris, K. P. Adhikari, C. S. Whisnant, C. Hanretty, L. Lanza, R. Dupre, M. Battaglieri, M. Lowry, S. Strauch, Eugene Pasyuk, N. Dashyan, Yordanka Ilieva, L. Barion, G. Ciullo, D. S. Carman, S. Fegan, D. P. Watts, A. V. Sarantsev, N. Tyler, J. A. Tan, P. Chatagnon, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and CLAS

Subjects
Nuclear and High Energy Physics, Socio-culturale, nucleon resonance, Nucleons, Photoproduction, Mesons, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, K+: photoproduction, Particle identification, Nuclear physics, chemistry.chemical_compound, PE2_2, PE2_1, CLAS, 0103 physical sciences, Neutron, Hydrogen deuteride, n: target, 010306 general physics, Nuclear Experiment, PE2_3, photon: beam, Physics, 010308 nuclear & particles physics, nucleus: target, Settore FIS/04, Resonance, helicity: asymmetry, Observable, Sigma-: photoproduction, Helicity, lcsh:QC1-999, chemistry, Excited state, spectrometer, Nucleon, lcsh:Physics, Jefferson Lab, experimental results
Abstract

We report a measurement of a beam–target double-polarisation observable (E) for the γ→n→(p)→K+Σ−(p) reaction. The data were obtained impinging the circularly-polarised energy-tagged photon beam of Hall B at Jefferson Lab on a longitudinally-polarised frozen-spin hydrogen deuteride (HD) nuclear target. The E observable for an effective neutron target was determined for centre-of-mass energies 1.70≤W≤2.30 GeV, with reaction products detected over a wide angular acceptance by the CLAS spectrometer. These new double-polarisation data give unique constraints on the strange decays of excited neutron states. Inclusion of the new data within the Bonn-Gatchina theoretical model results in significant changes for the extracted photocouplings of a number of established nucleon resonances. Possible improvements in the PWA description of the experimental data with additional “missing” resonance states, including the N(2120)3/2− resonance, are also quantified.

Published
2020
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50. The CLAS12 Spectrometer at Jefferson Laboratory

Author

C. W. Kim, H. Avakian, D. Protopopescu, D. Heddle, M. Contalbrigo, M. L. Kabir, H. Voskanyan, E. Voutier, T. Chetry, M. Zarecky, J. Poudel, I. Illari, B. A. Clary, M. Osipenko, D. Insley, D. P. Watts, I. Bedlinskiy, Michael Paolone, V. Sergeyeva, D. Kashy, M. Khachatryan, F. Hauenstein, V. Mascagna, Nikolaos Sparveris, F. Bossu, D. Marchand, W. Kim, G. Niculescu, P. Bonneau, G. Charles, P. Hemler, Ruben J. Fair, P. Moran, Dustin Keller, C. Ayerbe Gayoso, Nicholas Zachariou, M. Ungaro, C. Munoz Camacho, M. J. Amaryan, G. Rosner, I. J. D. MacGregor, T. A. Forest, V. Lucherini, S. E. Kuhn, Y. Prok, M. Hattawy, S. Stepanyan, Michael Wood, K. Hafidi, M. D. Mestayer, S. Lee, M. Wiseman, F. Sabatié, R. Paremuzyan, N. Dashyan, A. Deur, K. Hicks, K. Joo, E. L. Isupov, N. A. Baltzell, R. W. Gothe, S. Christo, L. C. Smith, B. S. Ishkhanov, Latifa Elouadrhiri, V. Baturin, Nicholas M. Harrison, Gerard Gilfoyle, M. McMullen, G. E. Dodge, H. S. Jo, R. Johnston, A. Yegneswaran, K. Livingston, A. Lung, P. Stoler, M. Guidal, D. Sokhan, K. Price, Aditya R. Khanal, K. P. Adhikari, Jie Zhang, K. Bruhwel, S. Adhikari, S. Boyarinov, B. McKinnon, M. Ehrhart, M. Leali, Z. W. Zhao, S. Joosten, B. J. Roy, V. P. Kubarovsky, J. Newton, P. Chatagnon, G. V. Fedotov, D. Tilles, M.A. Antonioli, Renuka Rajput-Ghoshal, G. D. Smith, M. Holtrop, C. Cuevas, V. Gyurjyan, Probir K. Ghoshal, Yordanka Ilieva, H. Hakobyan, Alexander Schmidt, Luciano Pappalardo, Andrea Bianconi, W. J. Briscoe, M. Turisini, M. Mirazita, D. I. Glazier, M. Garçon, M. Ripani, F. X. Girod, A. Filippi, K. L. Giovanetti, R. Miller, J. Ritman, S. Diehl, R. De Vita, C. D. Keith, Y. G. Sharabian, M. Lowry, M. Defurne, E. Pasyuk, P. Naidoo, J. Hogan, N. Markov, Or Hen, C. Salgado, M. Taylor, G. Young, S. Strauch, Larry Weinstein, H. Atac, Chaden Djalali, A. Hobart, A. Kim, Z. E. Meziani, S. Schadmand, U. Shrestha, T. Ewing, T. Mineeva, O. Pogorelko, S. Nanda, L. Barion, G. Angelini, J. Rowley, P. Rossi, M. Leffel, William Brooks, I. Mandjavidze, L. Venturelli, Iu. Skorodumina, Y. Gotra, C. Mealer, J. W. Price, S. Aune, C. Wiggins, D. G. Ireland, G. Gavalian, G. Jacobs, V. Crede, Volker D. Burkert, A. S. Biselli, O. Pastor, Victor Mokeev, E.P. Segarra, Ross Milner, N. Tyler, J. A. Tan, E. Golovatch, R. Dupre, W. Phelps, Andrea Celentano, S. Procureur, M. Cook, G. Ciullo, M. Battaglieri, D. S. Carman, B. Raydo, A. Rizzo, X. Wei, R. Cruz-Torres, S. Niccolai, K. A. Griffioen, B. Eng, A. Movsisyan, P. L. Cole, L. Lanza, G. Christiaens, A. D'Angelo, T. Kageya, L. El Fassi, P. Lenisa, V. Ziegler, C. Hanretty, D. Anderson, T. B. Hayward, Brian Raue, Fatiha Benmokhtar, O. Soto, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), and Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics::Instrumentation and Detectors, data acquisition, magnet: solenoid, superconductivity: torus, Solenoid, 01 natural sciences, Particle identification, Luminosity, momentum resolution, electron: beam, Nuclear Experiment, Instrumentation, QC, Physics, Luminosity (scattering theory), Settore FIS/04, Detector, Magnetic spectrometer, magnet: torus, performance, Nuclear and High Energy Physics, Meson, vertex detector, nucleon: interaction, CLAS12, Electromagnetic physics, Large acceptance, Socio-culturale, fabrication, beam: energy, Nuclear physics, PE2_1, CLAS, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, PE2_3, scintillation counter, Cherenkov radiation, detector: design, activity report, Spectrometer, 010308 nuclear & particles physics, nucleus, CLAS12, Electromagnetic physics, Large acceptance, Luminosity, Magnetic spectrometer, magnet: superconductivity, magnetic spectrometer, electromagnetic physics, large acceptance, luminosity, neutral particle, Automatic Keywords, calorimeter: electromagnetic, Cherenkov counter, spectrometer, particle identification, Beam (structure)
Abstract

International audience; The CEBAF Large Acceptance Spectrometer for operation at 12 GeV beam energy (CLAS12) in Hall B at Jefferson Laboratory is used to study electro-induced nuclear and hadronic reactions. This spectrometer provides efficient detection of charged and neutral particles over a large fraction of the full solid angle. CLAS12 has been part of the energy-doubling project of Jefferson Lab’s Continuous Electron Beam Accelerator Facility, funded by the United States Department of Energy. An international collaboration of 48 institutions contributed to the design and construction of detector hardware, developed the software packages for the simulation of complex event patterns, and commissioned the detector systems. CLAS12 is based on a dual-magnet system with a superconducting torus magnet that provides a largely azimuthal field distribution that covers the forward polar angle range up to 35 ∘ , and a solenoid magnet and detector covering the polar angles from 35° to 125° with full azimuthal coverage. Trajectory reconstruction in the forward direction using drift chambers and in the central direction using a vertex tracker results in momentum resolutions of < 1% and < 3%, respectively. Cherenkov counters, time-of-flight scintillators, and electromagnetic calorimeters provide good particle identification. Fast triggering and high data-acquisition rates allow operation at a luminosity of 1035 cm −2 s −1 . These capabilities are being used in a broad program to study the structure and interactions of nucleons, nuclei, and mesons, using polarized and unpolarized electron beams and targets for beam energies up to 11 GeV. This paper gives a general description of the design, construction, and performance of CLAS12.

Published
2020
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