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32 results on '"Rakhman, A."'

1. Laser Manipulation of H- Beams: a Snowmass 2022 White Paper

Author

Rakhman, Abdurahim

Subjects
Physics - Accelerator Physics, Nuclear Experiment
Abstract

Future high-power (10 - 20 MW) hadron accelerators offer many unique opportunities for fundamental science and nuclear applications. With the completion of Proton Power Upgrade (PPU) at 2.8 MW [1] and European Spallation Source (ESS) at 5 MW [2], the attention will be focused on the next high-power machine in hadron accelerator community. Charge exchange injection into a synchrotron using diamond stripper foils offers great advantage over direct proton acceleration. However, there are clear limitations associated with foil sublimation above critical beam power density and beam loss due to scattering (~10 rem/hour at 10 MW for SNS)., Comment: white paper

Published
2022

2. Deeply virtual Compton scattering off the neutron

Author

Benali, M., Desnault, C., Mazouz, M., Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., Defurne, M., de Jager, C. W., de Leo, R., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Huber, G. M., Hyde, C. E., Iqbal, S., Itard, F., Kang, Ho., Kang, Hy., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jimenez-Arguello, A. Marti, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Pomatsalyuk, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatie, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zana, L., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.

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

The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high energy electron is scattered off a nucleon by exchanging a virtual photon. Then, a highly-energetic real photon is emitted from one of the quarks inside the nucleon, which carries information on the quark's transverse position and longitudinal momentum. By measuring the cross-section of deeply virtual Compton scattering, Compton form factors related to the generalized parton distributions can be extracted. Here, we report the observation of unpolarized deeply virtual Compton scattering off a deuterium target. From the measured photon-electroproduction cross-sections, we have extracted the cross-section of a quasi-free neutron and a coherent deuteron. Due to the approximate isospin symmetry of quantum chromodynamics, we can determine the contributions from the different quark flavours to the helicity-conserved Compton form factors by combining our measurements with previous ones probing the proton's internal structure. These results advance our understanding of the description of the nucleon structure, which is important to solve the proton spin puzzle.

Published
2021
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3. Novel observation of isospin structure of short-range correlations in calcium isotopes

Author

Nguyen, D., Ye, Z., Aguilera, P., Ahmed, Z., Albataineh, H., Allada, K., Anderson, B., Anez, D., Aniol, K., Annand, J., Arrington, J., Averett, T., Baghdasaryan, H., Bai, X., Beck, A., Beck, S., Bellini, V., Benmokhtar, F., Camsonne, A., Chen, C., Chen, J. -P., Chirapatpimol, K., Cisbani, E., Dalton, M. M., Daniel, A., Day, D., Deconinck, W., Defurne, M., Flay, D., Fomin, N., Friend, M., Frullani, S., Fuchey, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, S., Gu, C., Guèye, P., Hanretty, C., Hansen, J. -O., Shabestari, M. Hashemi, Higinbotham, D. W., Huang, M., Iqbal, S., Jin, G., Kalantarians, N., Kang, H., her, A. Kelle, Korover, I., LeRose, J., Leckey, J., Li, S., Lindgren, R., Long, E., Mammei, J., Margaziotis, D. J., Markowitz, P., Meekins, D., Meziani, Z. -E., Michaels, R., Mihovilovi\v, M., Muangma, N., Camacho, C. Munoz, Norum, B. E., Nuruzzaman, Pan, K., Phillips, S., Piasetzky, E., Pomerantz, I., Posik, M., Punjabi, V., Qian, X., Qiang, Y., Qiu, X., Reimer, P. E., Rakhman, A., Riordan, S., Ron, G., Rondon-Aramayo, O., Saha, A., Selvy, L., Shahinyan, A., Shneor, R., \v, S., Slifer, K., Solvignon, P., Sparveris, N., Subedi, R., Sulkosky, V., Wang, D., Watson, J. W., Weinstein, L. B., Wojtsekhowski, B., Wood, S. A., Yaron, I., Zhan, X., Zhang, J., Zhang, Y. W., Zhao, B., Zheng, X., Zhu, P., and Zielinski, R.

Subjects
Nuclear Experiment
Abstract

Short Range Correlations (SRCs) have been identified as being responsible for the high momentum tail of the nucleon momentum distribution, n(k). Hard, short-range interactions of nucleon pairs generate the high momentum tail and imprint a universal character on n(k) for all nuclei at large momentum. Triple coincidence experiments have shown a strong dominance of np pairs, but these measurements involve large final state interactions. This paper presents the results from Jefferson Lab experiment E08014 which measured inclusive electron scattering cross-section from Ca isotopes. By comparing the inclusive cross section from 48Ca to 40Ca in a kinematic region dominated by SRCs we provide a new way to study the isospin structure of SRCs., Comment: 7 pages, 3 figures

Published
2020
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4. Laser-assisted high-energy proton pulse extraction for feasibility study of co-located muon source at the SNS

Author

Liu, Yun, Rakhman, Abdurahim, Long, Cary D., Liu, Yuan, and Williams, Travis J.

Subjects
Physics - Accelerator Physics, Physics - Instrumentation and Detectors
Abstract

We have experimentally demonstrated the first non-intrusive 1-GeV proton beam extraction for the generation of muons with a temporal structure optimized for Muon Spin Relaxation/Rotation/Resonance (MuSR) applications. The proton pulses are extracted based on the laser neutralization of 1 GeV hydrogen ion (H-) beam in the high energy beam transport of the Spallation Neutron Source (SNS) accelerator. The maximum flux of the extracted proton beam accounts for only 0.2% of the total proton beam used for neutron production, a marked difference from the 20% reduction at other co-located muon and neutron facilities, and thus the proposed method will result in negligible impact on the SNS operation. This paper describes the development of a fiber/solid-state hybrid laser system that has high flexibility of pulse structure and output power, initial experiments on laser neutralization of H- beam and separation of H0 beam from the existing SNS accelerator beam line, conversion of H0 to proton at the SNS linac dump, and measurement results of 30 ns/50 kHz proton pulses. This system conclusively demonstrates the feasibility of laser-based proton beam extraction to power a world-leading MuSR facility at the SNS.

Published
2020
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5. Probing for high momentum protons in $^4$He via the $^4He(e,e'p)X$ reaction

Author

Iqbal, S., Benmokhtar, F., Ivanov, M., See, N., Aniol, K., Higinbotham, D. W., Boyd, C., Gadsby, A., Gilad, S., Saha, A., Udias, J. M., Goodwill, J. S., Finton, D., Boyer, A., Ye, Z., Solvignon, P., Aguilera, P., Ahmed, Z., Albataineh, H., Allada, K., Anderson, B., Anez, D., Annand, J., Arrington, J., Averett, T., Baghdasaryan, H., Bai, X., Beck, A., Beck, S., Bellini, V., Camsonne, A., Chen, C., Chen, J. -P., Chirapatpimol, K., Cisbani, E., Dalton, M. M., Daniel, A., Day, D., Deconinck, W., Defurne, M., Flay, D., Fomin, N., Friend, M., Frullani, S., Fuchey, E., Garibaldi, F., Gaskell, D., Gilman, R., Glamazdin, S., Gu, C., Gueye, P., Hanretty, C., Hansen, J. -O., Shabestari, M. Hashemi, Huang, M., Jin, G., Kalantarians, N., Kang, H., Kelleher, A., Korover, I., LeRose, J., Leckey, J., Lindgren, R., Long, E., Mammei, J., Margaziotis, D. J., Markowitz, P., Meekins, D., Meziani, Z., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Munoz, Norum, B., Nuruzzaman, Nuruzzaman, Pan, K., Phillips, S., Piasetzky, E., Pomerantz, I., Posik, M., Punjabi, V., Qian, X., Qiang, Y., Qiu, X., Reimer, P. E., Rakhman, A ., Riordan, S., Ron, G., Rondon-Aramayo, O., Selvy, L., Shahinyan, A., Shneor, R., Sirca, S., Slifer, K., Sparveris, N., Subedi, R., Sulkosky, V., Wang, D., Watson, J. W., Weinstein, L. B., Wojtsekhowski, B., Wood, S. A., Yaron, I., Zhan, X., Zhang, J., Zhang, Y. W., Zhao, B., Zheng, X., Zhu, P., and Zielinski, R.

Subjects
Nuclear Experiment
Abstract

Experimental cross sections for the $^4He(e,e'p)X$ reaction up to a missing momentum of 0.632 GeV/$c$ at $x_B=1.24$ and $Q^2$=2(GeV/$c$)$^2$ are reported. The data are compared to Relativistic Distorted Wave Impulse Approximation(RDWIA) calculations for $^4He(e,e'p)^3H$ channel. Significantly more events in the triton mass region are measured for $p_{m}$$>$0.45 GeV/$c$ than are predicted by the theoretical model, suggesting that the effects of initial-state multi-nucleon correlations are stronger than expected by the RDWIA model., Comment: Submitted to PRC

Published
2019

6. High efficiency laser-assisted H- charge exchange for microsecond duration beams

Author

Cousineau, Sarah, Rakhman, Abdurahim, Kay, Martin, Aleksandrov, Alexander, Danilov, Viatcheslav, Gorlov, Timofey, Liu, Yun, Long, Cary, Menshov, Alexander, Plum, Michael, Shishlo, Andrei, Webster, Andrew, and Johnson, David

Subjects
Physics - Accelerator Physics
Abstract

Laser-assisted stripping is a novel approach to H- charge exchange that overcomes long-standing limitations associated with the traditional, foil-based method of producing high-intensity, time-structured beams of protons. This paper reports on the first successful demonstration of the laser stripping technique for microsecond duration beams. The experiment represents a factor of 1000 increase in the stripped pulse duration compared with the previous proof-of-principle demonstration. The central theme of the experiment is the implementation of methods to reduce the required average laser power such that high efficiency stripping can be accomplished for microsecond duration beams using conventional laser technology. The experiment was performed on the Spallation Neutron Source 1 GeV H- beam using a 1 MW peak power UV laser and resulted in ~95% stripping efficiency., Comment: 17 pp

Published
2018
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7. Search for three-nucleon short-range correlations in light nuclei

Author

Ye, Z., Solvignon, P., Nguyen, D., Aguilera, P., Ahmed, Z., Albataineh, H., Allada, K., Anderson, B., Anez, D., Aniol, K., Annand, J., Arrington, J., Averett, T., Baghdasaryan, H., Bai, X., Beck, A., Beck, S., Bellini, V., Benmokhtar, F., Camsonne, A., Chen, C., Chen, J. -P., Chirapatpimol, K., Cisbani, E., Dalton, M. M., Daniel, A., Day, D., Deconinck, W., Defurne, M., Flay, D., Fomin, N., Friend, M., Frullani, S., Fuchey, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, S., Gu, C., Gueye, P., Hanretty, C., Hansen, J. -O., Shabestari, M. Hashemi, Higinbotham, D. W., Huang, M., Iqbal, S., Jin, G., Kalantarians, N., Kang, H., Kelleher, A., Korover, I., LeRose, J., Leckey, J., Lindgren, R., Long, E., Mammei, J., Margaziotis, D. J., Markowitz, P., Meekins, D., Meziani, Z., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Munoz, Norum, B., Nuruzzaman, Pan, K., Phillips, S., Piasetzky, E., Pomerantz, I., Posik, M., Punjabi, V., Qian, X., Qiang, Y., Qiu, X., Reimer, P. E., Rakhman, A., Riordan, S., Ron, G., Rondon-Aramayo, O., Saha, A., Selvy, L., Shahinyan, A., Shneor, R., Sirca, S., Slifer, K., Sparveris, N., Subedi, R., Sulkosky, V., Wang, D., Watson, J. W., Weinstein, L. B., Wojtsekhowski, B., Wood, S. A., Yaron, I., Zhan, X., Zhang, J., Zhang, Y. W., Zhao, B., Zheng, X., Zhu, P., and Zielinski, R.

Subjects
Nuclear Experiment
Abstract

We present new data probing short-range correlations (SRCs) in nuclei through the measurement of electron scattering off high-momentum nucleons in nuclei. The inclusive 4He/3He cross section ratio is observed to be both x and Q2 independent for 1.5 < x < 2, confirming the dominance of two- nucleon (2N) short-range correlations (SRCs). For x > 2, our data do not support a previous claim of three-nucleon (3N) correlation dominance. While contributions beyond those from stationary 2N- SRCs are observed, our data show that isolating 3N-SRCs is more complicated than for 2N-SRCs., Comment: 6 pages, 2 figures, new experimental results from JLab E08-014

Published
2017
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8. A Glimpse of Gluons through Deeply Virtual Compton Scattering on the Proton

Author

Defurne, M., Jiménez-Argüello, A. Martì, Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Hyde, C. E., Iqbal, S., Itard, F., Kang, H., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Mazouz, M., Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatié, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.

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

The proton is composed of quarks and gluons, bound by the most elusive mechanism of strong interaction called confinement. In this work, the dynamics of quarks and gluons are investigated using deeply virtual Compton scattering (DVCS): produced by a multi-GeV electron, a highly virtual photon scatters off the proton which subsequently radiates a high energy photon. Similarly to holography, measuring not only the magnitude but also the phase of the DVCS amplitude allows to perform 3D images of the internal structure of the proton. The phase is made accessible through the quantum-mechanical interference of DVCS with the Bethe-Heitler (BH) process, in which the final photon is emitted by the electron rather than the proton. We report herein the first full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the high energy regime where the scattering process is expected to occur off a single quark in the proton, these accurate measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.

Published
2017
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9. Rosenbluth separation of the $\pi^0$ Electroproduction Cross Section off the Neutron

Author

Mazouz, M., Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., Defurne, M., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Huber, G. M., Hyde, C. E., Iqbal, S., Itard, F., Kang, Ho., Kang, Hy., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jiménez-Argüello, A. Martí, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Muñoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatié, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zana, L., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report the first longitudinal/transverse separation of the deeply virtual exclusive $\pi^0$ electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions $d\sigma_L/dt$, $d\sigma_T/dt$, $d\sigma_{LT}/dt$ and $d\sigma_{TT}/dt$ are extracted as a function of the momentum transfer to the recoil system at $Q^2$=1.75 GeV$^2$ and $x_B$=0.36. The $ed \to ed\pi^0$ cross sections are found compatible with the small values expected from theoretical models. The $en \to en\pi^0$ cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity GPDs of the nucleon. By combining these results with previous measurements of $\pi^0$ electroproduction off the proton, we present a flavor decomposition of the $u$ and $d$ quark contributions to the cross section., Comment: 6 pages, 6 figures, Submitted to Phys. Rev. Lett

Published
2017
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10. First measurement of unpolarized SIDIS cross section and cross section ratios from a $^3$He target

Author

Yan, X., Allada, K., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F, Iodice, M., Jiang, X., Jin, G., Jones, M. K., Katich, J., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liu, T., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Munoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. -C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qian, X., Qiang, Y., Rakhman, A., Ransome, R., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Sirca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, W. A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Wang, Y., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zhao, Y. X., Zheng, X., Zhu, L., Zhu, X., and Zong, X.

Subjects
Nuclear Experiment
Abstract

The unpolarized semi-inclusive deep-inelastic scattering (SIDIS) differential cross sections in $^3$He($e,e^{\prime}\pi^{\pm}$)$X$ have been measured for the first time in Jefferson Lab experiment E06-010 performed with a $5.9\,$GeV $e^-$ beam on a $^3$He target. The experiment focuses on the valence quark region, covering a kinematic range $0.12 < x_{bj} < 0.45$, $1 < Q^2 < 4 \, \textrm{(GeV/c)}^2$, $0.45 < z_{h} < 0.65$, and $0.05 < P_t < 0.55 \, \textrm{GeV/c}$. The extracted SIDIS differential cross sections of $\pi^{\pm}$ production are compared with existing phenomenological models while the $^3$He nucleus approximated as two protons and one neutron in a plane wave picture, in multi-dimensional bins. Within the experimental uncertainties, the azimuthal modulations of the cross sections are found to be consistent with zero.

Published
2016
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11. Rosenbluth separation of the $\pi^0$ electroproduction cross section

Author

Defurne, M., Mazouz, M., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Hyde, C. E., Iqbal, S., Itard, F., Kang, H., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jimenez-Arguello, A. Marti, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabati, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zafar, A., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We present deeply virtual $\pi^0$ electroproduction cross-section measurements at $x_B$=0.36 and three different $Q^2$--values ranging from 1.5 to 2 GeV$^2$, obtained from experiment E07-007 that ran in the Hall A at Jefferson Lab. The Rosenbluth technique was used to separate the longitudinal and transverse responses. Results demonstrate that the cross section is dominated by its transverse component, and thus is far from the asymptotic limit predicted by perturbative Quantum Chromodynamics. An indication of a non-zero longitudinal contribution is provided by the interference term $\sigma_{LT}$ also measured. Results are compared with several models based on the leading twist approach of Generalized Parton Distributions (GPDs). In particular, a fair agreement is obtained with models where the scattering amplitude is described by a convolution of chiral-odd (transversity) GPDs of the nucleon with the twist-3 pion distribution amplitude. Therefore, neutral pion electroproduction may offer the exciting possibility of accessing transversity GPDs through experiment., Comment: Submitted to Physical Review Letters

Published
2016
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12. Measurements of $d_{2}^{n}$ and $A_{1}^{n}$: Probing the neutron spin structure

Author

Flay, D., Posik, M., Parno, D. S., Allada, K., Armstrong, W., Averett, T., Benmokhtar, F., Bertozzi, W., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Choi, S., Chudakov, E., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Franklin, G. B., Friend, M., Gao, H., Garibaldi, F., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Gomez, J., Guo, L., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Hyde, C., Ibrahim, H. F., Jiang, X., Jin, G., Katich, J., Kelleher, A., Kolarkar, A., Korsch, W., Kumbartzki, G., LeRose, J. J., Lindgren, R., Liyanage, N., Long, E., Lukhanin, A., Mamyan, V., McNulty, D., Meziani, Z. -E., Michaels, R., Mihovilovič, M., Moffit, B., Muangma, N., Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Peng, J. C., Qian, X., Qiang, Y., Rakhman, A., Riordan, S., Saha, A., Sawatzky, B., Shabestari, M. H., Shahinyan, A., Širca, S., Solvignon, P., Subedi, R., Sulkosky, V., Tobias, A., Troth, W., Wang, D., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., and Zheng, X.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We report on the results of the E06-014 experiment performed at Jefferson Lab in Hall A, where a precision measurement of the twist-3 matrix element $d_2$ of the neutron ($d_{2}^{n}$) was conducted. This quantity represents the average color Lorentz force a struck quark experiences in a deep inelastic electron scattering event off a neutron due to its interaction with the hadronizing remnants. This color force was determined from a linear combination of the third moments of the spin structure functions $g_1$ and $g_2$ on $^{3}$He after nuclear corrections had been applied to these moments. The kinematics included two average $Q^{2}$ bins of $3.2$ GeV$^{2}$ and $4.3$ GeV$^{2}$, and Bjorken-$x$ $0.25 \leq x \leq 0.90$ covering the DIS and resonance regions. We found $d_2^n$ to be small and negative for $ = 3.2$ GeV$^{2}$, and smaller for $ = 4.3$ GeV$^{2}$, consistent with a lattice QCD calculation. The twist-4 matrix element $f_{2}^{n}$ was extracted by combining our $d_{2}^{n}$ with the world data on $\Gamma_{1}^{n} = \int_{0}^{1} g_{1}^{n} dx$. We found $f_{2}^{n}$ to be roughly an order of magnitude larger than $d_{2}^{n}$. Utilizing the extracted $d_{2}^{n}$ and $f_{2}^{n}$ data, we separated the color force into its electric and magnetic components, $F_{E}^{y,n}$ and $F_{B}^{y,n}$, and found them to be equal and opposite in magnitude, in agreement with instanton model predictions but not with those from QCD sum rules. Additionally, we have extracted the neutron virtual photon-nucleon asymmetry $A_{1}^{n}$, the structure function ratio $g_{1}^{n}/F_{1}^{n}$, and the quark ratios $(\Delta u + \Delta \bar{u})/(u + \bar{u})$ and $(\Delta d + \Delta \bar{d})/(d + \bar{d})$. These results were found to be consistent with DIS world data and with the prediction of the constituent quark model but at odds with those of perturbative QCD at large $x$., Comment: 55 Pages, 45 figures, 48 tables. 15 supplemental files. Grammatical and typo fixes. Revised some model descriptions and updated analyses for f_2^n and color forces

Published
2016
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13. A high-finesse Fabry-Perot cavity with a frequency-doubled green laser for precision Compton polarimetry at Jefferson Lab

Author

Rakhman, A., Hafez, M., Nanda, S., Benmokhtar, F., Camsonne, A., Cates, G. D., Dalton, M. M., Franklin, G. B., Friend, M., Michaels, R. W., Nelyubin, V., Parno, D. S., Paschke, K. D., Quinn, B. P., Souder, P. A., and Tobias, W. A.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

A high-finesse Fabry-Perot cavity with a frequency-doubled continuous wave green laser (532~nm) has been built and installed in Hall A of Jefferson Lab for high precision Compton polarimetry. The infrared (1064~nm) beam from a ytterbium-doped fiber amplifier seeded by a Nd:YAG nonplanar ring oscillator laser is frequency doubled in a single-pass periodically poled MgO:LiNbO$_{3}$ crystal. The maximum achieved green power at 5 W IR pump power is 1.74 W with a total conversion efficiency of 34.8\%. The green beam is injected into the optical resonant cavity and enhanced up to 3.7~kW with a corresponding enhancement of 3800. The polarization transfer function has been measured in order to determine the intra-cavity circular laser polarization within a measurement uncertainty of 0.7\%. The PREx experiment at Jefferson Lab used this system for the first time and achieved 1.0\% precision in polarization measurements of an electron beam with energy and current of 1.0~GeV and 50~$\mu$A., Comment: 20 pages, 22 figures, revised version of arXiv:1601.00251v1, submitted to NIMA

Published
2016
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14. Double Spin Asymmetries of Inclusive Hadron Electroproductions from a Transversely Polarized $^3\rm{He}$ Target

Author

The Jefferson Lab Hall A Collaboration, Zhao, Y. X., Allada, K., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F, Iodice, M., Jiang, X., Jin, G., Jones, M. K., Katich, J., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muñoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. -C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qian, X., Qiang, Y., Rakhman, A., Ransome, R., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Širca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, W. A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Wang, Y., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.

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

We report the measurement of beam-target double-spin asymmetries ($A_\text{LT}$) in the inclusive production of identified hadrons, $\vec{e}~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a longitudinally polarized 5.9 GeV electron beam and a transversely polarized $^3\rm{He}$ target. Hadrons ($\pi^{\pm}$, $K^{\pm}$ and proton) were detected at 16$^{\circ}$ with an average momentum $<$$P_h$$>$=2.35 GeV/c and a transverse momentum ($p_{T}$) coverage from 0.60 to 0.68 GeV/c. Asymmetries from the $^3\text{He}$ target were observed to be non-zero for $\pi^{\pm}$ production when the target was polarized transversely in the horizontal plane. The $\pi^{+}$ and $\pi^{-}$ asymmetries have opposite signs, analogous to the behavior of $A_\text{LT}$ in semi-inclusive deep-inelastic scattering., Comment: Published in PRC (92.015207), nuclear experiment, high-energy experiment

Published
2015
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15. A precision measurement of the $p$($e,e^\prime p\,$)$\pi^0$ reaction at threshold

Author

Chirapatpimol, K., Shabestari, M. H., Lindgren, R. A., Smith, L. C., Annand, J. R. M., Higinbotham, D. W., Moffit, B., Nelyubin, V., Norum, B. E., Allada, K., Aniol, K., Ardashev, K., Armstrong, D. S., Arndt, R. A., Benmokhtar, F., Bernstein, A. M., Bertozzi, W., Briscoe, W. J., Bimbot, L., Camsonne, A., Chen, J. -P., Choi, S., Chudakov, E., Cisbani, E., Cusanno, F., Dalton, M. M., Dutta, C., Egiyan, K., Fernandez-Ramirez, C., Feuerbach, R., Fissum, K. G., Frullani, S., Garibaldi, F., Gayou, O., Gilman, R., Gilad, S., Goity, J., Gomez, J., Hahn, B., Hamilton, D., Hansen, J. -O., Huang, J., Igarashi, R., Ireland, D., de Jager, C. W., Jin, X., Jiang, X., Jinasundera, T., Kellie, J., Keppel, C. E., Kolb, N., LeRose, J., Liyanage, N., Livingston, K., McNulty, D., Mercado, L., Michaels, R., Mihovilovic, M., Qian, S., Qian, X., Mailyan, S., Mamyan, V., Marrone, S., Monaghan, P., Nanda, S., Perdrisat, C. F., Piasetzky, E., Protopopescu, D., Punjabi, V., Qiang, Y., Rachek, I. A., Rakhman, A., Ron, G., Rosner, G., Saha, A., Sawatzky, B., Shahinyan, A., Sirca, S., Sparveris, N., Subedi, R. R., Suleiman, R., Strakovsky, I., Sulkosky, V., Moinelo, J., Voskanyan, H., Wang, K., Wang, Y., Watson, J., Watts, D., Wojtsekhowski, B., Workman, R. L., Yao, H., Zhan, X., and Zhang, Y.

Subjects
Nuclear Experiment
Abstract

New results are reported from a measurement of $\pi^0$ electroproduction near threshold using the $p(e,e^{\prime} p)\pi^0$ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the $\phi^*_{\pi}$ and $\theta^*_{\pi}$ angles in the $p \pi^0$ center-of-mass was obtained for invariant energies above threshold from 0.5 MeV up to 15 MeV. The 4-momentum transfer $Q^2$ coverage ranges from 0.05 to 0.155 (GeV/c)$^2$ in fine steps. A simple phenomenological analysis of our data shows strong disagreement with $p-$wave predictions from ChPT for $Q^2>0.07$ (GeV/c)$^2$, while the $s-$wave predictions are in reasonable agreement., Comment: 5 pages, 6 figures

Published
2015
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16. Measurement of Parity-Violating Asymmetry in Electron-Deuteron Inelastic Scattering

Author

Wang, D., Pan, K., Subedi, R., Ahmed, Z., Allada, K., Aniol, K. A., Armstrong, D. S., Arrington, J., Bellini, V., Beminiwattha, R., Benesch, J., Benmokhtar, F., Bertozzi, W., Camsonne, A., Canan, M., Cates, G. D., Chen, J. -P., Chudakov, E., Cisbani, E., Dalton, M. M., de Jager, C. W., De Leo, R., Deconinck, W., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Erler, J., Flay, D., Franklin, G. B., Friend, M., Frullani, S., Garibaldi, F., Gilad, S., Giusa, A., Glamazdin, A., Golge, S., Grimm, K., Hafidi, K., Hansen, J. -O., Higinbotham, D. W., Holmes, R., Holmstrom, T., Holt, R. J., Huang, J., Hyde, C. E., Jen, C. M., Jones, D., Kang, Hoyoung, King, P. M., Kowalski, S., Kumar, K. S., Lee, J. H., LeRose, J. J., Liyanage, N., Long, E., McNulty, D., Margaziotis, D. J., Meddi, F., Meekins, D. G., Mercado, L., Meziani, Z. -E., Michaels, R., Mihovilovic, M., Muangma, N., Mesick, K. E., Nanda, S., Narayan, A., Nelyubin, V., Nuruzzaman, A., Oh, Y., Parno, D., Paschke, K. D., Phillips, S. K., Qian, X., Qiang, Y., Quinn, B., Rakhman, A., Reimer, P. E., Rider, K., Riordan, S., Roche, J., Rubin, J., Russo, G., Saenboonruang, K., Saha, A., Sawatzky, B., Shahinyan, A., Silwal, R., Širca, S., Souder, P. A., Suleiman, R., Sulkosky, V., Sutera, C. M., Tobias, W. A., Urciuoli, G. M., Waidyawansa, B., Wojtsekhowski, B., Ye, L., Zhao, B., and Zheng, X.

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

The parity-violating asymmetries between a longitudinally-polarized electron beam and an unpolarized deuterium target have been measured recently. The measurement covered two kinematic points in the deep inelastic scattering region and five in the nucleon resonance region. We provide here details of the experimental setup, data analysis, and results on all asymmetry measurements including parity-violating electron asymmetries and those of inclusive pion production and beam-normal asymmetries. The parity-violating deep-inelastic asymmetries were used to extract the electron-quark weak effective couplings, and the resonance asymmetries provided the first evidence for quark-hadron duality in electroweak observables. These electron asymmetries and their interpretation were published earlier, but are presented here in more detail., Comment: 50 pages, submitted to Phys. Rev. C

Published
2014
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17. Precision Measurements of $A_1^n$ in the Deep Inelastic Regime

Author

Parno, D. S., Flay, D., Posik, M., Allada, K., Armstrong, W., Averett, T., Benmokhtar, F., Bertozzi, W., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Choi, S., Chudakov, E., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Franklin, G. B., Friend, M., Gao, H., Garibaldi, F., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Gomez, J., Guo, L., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Hyde, C., Ibrahim, H. F., Jiang, X., Jin, G., Katich, J., Kelleher, A., Kolarkar, A., Korsch, W., Kumbartzki, G., LeRose, J. J., Lindgren, R., Liyanage, N., Long, E., Lukhanin, A., Mamyan, V., McNulty, D., Meziani, Z. -E., Michaels, R., Mihovilovič, M., Moffit, B., Muangma, N., Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Nuruzzaman, Oh, Y., Peng, J. C., Qian, X., Qiang, Y., Rakhman, A., Riordan, S., Saha, A., Sawatzky, B., Shabestari, M. H., Shahinyan, A., Širca, S., Solvignon, P., Subedi, R., Sulkosky, V., Tobias, W. A., Troth, W., Wang, D., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

We have performed precision measurements of the double-spin virtual-photon asymmetry $A_1$ on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer. Our data cover a wide kinematic range $0.277 \leq x \leq 0.548$ at an average $Q^2$ value of 3.078~(GeV/c)$^2$, doubling the available high-precision neutron data in this $x$ range. We have combined our results with world data on proton targets to extract the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of an $A_1^n$ zero crossing near $x=0.5$. We find no evidence of a transition to a positive slope in $(\Delta d + \Delta \bar{d})/(d + \bar{d})$ up to $x=0.548$., Comment: 6 pages, 2 figures, 3 tables. Two typos corrected in Table 3

Published
2014
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18. Single Spin Asymmetries in Charged Kaon Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized $^3{\rm{He}}$ Target

Author

Zhao, Y. X., Wang, Y., Allada, K., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F, Iodice, M., Jiang, X., Jin, G., Jones, M. K., Katich, J., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muñoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. -C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qian, X., Qiang, Y., Rakhman, A., Ransome, R., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Širca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.

Subjects
Nuclear Experiment
Abstract

We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized $^3{\rm{He}}$ target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1$<$$x_{bj}$$<$0.4 for $K^{+}$ and $K^{-}$ production. While the Collins and Sivers moments for $K^{+}$ are consistent with zero within the experimental uncertainties, both moments for $K^{-}$ favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the world data. While the $K^{+}$ Sivers moments are consistent with the prediction, the $K^{-}$ results differ from the prediction at the 2-sigma level., Comment: 6 pages, 3 figures

Published
2014
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19. A Precision Measurement of the Neutron Twist-3 Matrix Element $d_2^n$: Probing Color Forces

Author

Posik, M., Flay, D., Parno, D. S., Allada, K., Armstrong, W., Averett, T., Benmokhtar, F., Bertozzi, W., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Choi, S., Chudakov, E., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Franklin, G. B., Friend, M., Gao, H., Garibaldi, F., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Gomez, J., Guo, L., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Hyde, C., Ibrahim, H. F., Jiang, X., Jin, G., Katich, J., Kelleher, A., Kolarkar, A., Korsch, W., Kumbartzki, G., LeRose, J. J., Lindgren, R., Liyanage, N., Long, E., Lukhanin, A., Mamyan, V., McNulty, D., Meziani, Z. -E., Michaels, R., Mihovilovič, M., Moffit, B., Muangma, N., Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Nuruzzaman, Oh, Y., Peng, J. C., Qian, X., Qiang, Y., Rakhman, A., Riordan, S., Saha, A., Sawatzky, B., Shabestari, M. H., Shahinyan, A., Širca, S., Solvignon, P., Subedi, R., Sulkosky, V., Tobias, W. A., Troth, W., Wang, D., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

Double-spin asymmetries and absolute cross sections were measured at large Bjorken $x$ (0.25 $ \le x \le $ 0.90), in both the deep-inelastic and resonance regions, by scattering longitudinally polarized electrons at beam energies of 4.7 and 5.9 GeV from a transversely and longitudinally polarized $^3$He target. In this dedicated experiment, the spin structure function $g_2$ on $^3$He was determined with precision at large $x$, and the neutron twist-three matrix element $d_2^n$ was measured at $\left< Q^2\right>$ of 3.21 and 4.32 GeV$^2$/$c^2$, with an absolute precision of about $10^{-5}$. Our results are found to be in agreement with lattice QCD calculations and resolve the disagreement found with previous data at $\left< Q^2\right> =$ 5 GeV$^2$/$c^2$. Combining $d_2^n$ and a newly extracted twist-four matrix element, $f_2^n$, the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about 30 MeV/fm in magnitude., Comment: Corrected a typo in the author list and Figure 1 legend. 6 pages, 2 figures, 2 tables

Published
2014
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20. Probing the Repulsive Core of the Nucleon-Nucleon Interaction via the 4He(e,e'pN) Triple-Coincidence Reaction

Author

Muangma, I. Korover N., Hen, O., Shneor, R., Sulkosky, V., Kelleher, A., Gilad, S., Higinbotham, D. W., Watson, E. Piasetzky J., Wood, S., Rakhman, Abdurahim, Aguilera, P., Ahmed, Z., Albataineh, H., Allada, K., Anderson, B., Anez, D., Aniol, K., Annand, J., Armstrong, W., Arrington, J., Averett, T., Badman, T., Baghdasaryan, H., Bai, X., Beck, A., Beck, S., Bellini, V., Benmokhtar, F., Bertozzi, W., Bittner, J., Boeglin, W., Camsonne, A., Chen, C., Chen, J. -P., Chirapatpimol, K., Cisbani, E., Dalton, M. M., Daniel, A., Day, D., de Jager, C. W., De Leo, R., Deconinck, W., Defurne, M., Flay, D., Fomin, N., Friend, M., Frullani, S., Fuchey, E., Garibaldi, F., Gaskell, D., Gilman, R., Glamazdin, O., Gu, C., Gueye, P., Hamilton, D., Hanretty, C., Hansen, O., Shabestari, M. Hashemi, Holmstrom, T., Huang, M., Iqbal, S., Jin, G., Kalantarians, N., Kang, H., Khandaker, M., LeRose, J., Leckey, J., Lindgren, R., Long, E., Mammei, J., Margaziotis, D. J., Markowitz, P., Jimenez-Arguello, A. Marti, Meekins, D., Meziani, Z., Michaels, R., Mihovilovic, M., Monaghan, P., Camacho, C. Munoz, Norum, B., Nuruzzaman, Pan, K., Phillips, S., Pomerantz, I., Posik, M., Punjabi, V., Qian, X., Qiang, Y., Qiu, X., Reimer, P. E., Riordan, S., Ron, G., Rondon-Aramayo, O., Saha, A., Schulte, E., Selvy, L., Shahinyan, A., Sirca, S., Sjoegren, J., Slifer, K., Solvignon, P., Sparveris, N., Subedi, R., Tireman, W., Wang, D., Weinstein, L. B., Wojtsekhowski, B., Yan, W., Yaron, I., Ye, Z., Zhan, X., Zhang, J., Zhang, Y., Zhao, B., Zhao, Z., Zheng, X., Zhu, P., and Zielinski, R.

Subjects
Nuclear Experiment
Abstract

We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q^2=2 [GeV/c]2 and x_B>1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum in a region where the nucleon-nucleon force is expected to change from predominantly tensor to repulsive. Neutron-proton pairs dominate the high-momentum tail of the nucleon momentum distributions, but their abundance is reduced as the nucleon momentum increases beyond ~500 MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum in the range we studied. Our data are compared with ab-initio calculations of two-nucleon momentum distributions in 4He., Comment: 6 pages, 2 figures

Published
2014
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21. Measurement of pretzelosity asymmetry of charged pion production in Semi-Inclusive Deep Inelastic Scattering on a polarized $^3$He target

Author

Zhang, Y., Qian, X., Allada, K., Dutta, C., Huang, J., Katich, J., Wang, Y., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, M., Ibrahim, H. F., Iodice, M., Jiang, X., Jin, G., Jones, M. K., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muñoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qiang, Y., Rakhman, A., Ransome, R. D., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Sirca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, W. A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.

Subjects
Nuclear Experiment
Abstract

An experiment to measure single-spin asymmetries in semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized $^3$He target was performed at Jefferson Lab in the kinematic region of $0.16

Published
2013
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22. Single Spin Asymmetries of Inclusive Hadrons Produced in Electron Scattering from a Transversely Polarized $^3$He Target

Author

Allada, K., Zhao, Y. X., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F, Iodice, M., Jiang, X., Jin, G., Jones, M. K., Katich, J., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Munoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. -C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qian, X., Qiang, Y., Rakhman, A., Ransome, R., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Sirca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, A., Urciuoli, G. M., Vilardi, I., Wang, K., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report the first measurement of target single-spin asymmetries (A$_N$) in the inclusive hadron production reaction, $e~$+$~^3\text{He}^{\uparrow}\rightarrow h+X$, using a transversely polarized $^3$He target. The experiment was conducted at Jefferson Lab in Hall A using a 5.9-GeV electron beam. Three types of hadrons ($\pi^{\pm}$, $\text{K}^{\pm}$ and proton) were detected in the transverse hadron momentum range 0.54 $

Published
2013
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23. Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction $^{3}\mathrm{He}^{\uparrow}(e,e')X$

Author

Katich, J., Qian, X., Zhao, Y. X., Allada, K., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, C., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Huang, M., Ibrahim, H. F., Iodice, M., Jiang, X., Jin, G., Jones, M. K., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muńoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qiang, Y., Rakhman, A., Ransome, R. D., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Širca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, A., Urciuoli, G. M., Vilardi, I., Wang, K., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.

Subjects
Nuclear Experiment
Abstract

We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction $^3$He$^{\uparrow}\left(e,e' \right)X$ on a polarized $^3$He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be non-zero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of $1.7 < W < 2.9$ GeV, $1.02$ GeV, which is non-zero at the $2.89\sigma$ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering., Comment: This is the final edited version as published in PRL

Published
2013
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24. Measurement of the Parity-Violating Asymmetry in Electron-Deuteron Scattering in the Nucleon Resonance Region

Author

Wang, D., Pan, K., Subedi, R., Deng, X., Ahmed, Z., Allada, K., Aniol, K. A., Armstrong, D. S., Arrington, J., Bellini, V., Beminiwattha, R., Benesch, J., Benmokhtar, F., Camsonne, A., Canan, M., Cates, G. D., Chen, J. -P., Chudakov, E., Cisbani, E., Dalton, M. M., de Jager, C. W., De Leo, R., Deconinck, W., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Franklin, G. B., Friend, M., Frullani, S., Garibaldi, F., Giusa, A., Glamazdin, A., Golge, S., Grimm, K., Hafidi, K., Hansen, O., Higinbotham, D. W., Holmes, R., Holmstrom, T., Holt, R. J., Huang, J., Hyde, C. E., Jen, C. M., Jones, D., Kang, H., King, P., Kowalski, S., Kumar, K. S., Lee, J. H., LeRose, J. J., Liyanage, N., Long, E., McNulty, D., Margaziotis, D. J., Meddi, F., Meekins, D. G., Mercado, L., Meziani, Z. -E., Michaels, R., Mihovilovic, M., Muangma, N., Myers, K. E., Nanda, S., Narayan, A., Nelyubin, V., Nuruzzaman, Oh, Y., Parno, D., Paschke, K. D., Phillips, S. K., Qian, X., Qiang, Y., Quinn, B., Rakhman, A., Reimer, P. E., Rider, K., Riordan, S., Roche, J., Rubin, J., Russo, G., Saenboonruang, K., Saha, A., Sawatzky, B., Shahinyan, A., Silwal, R., Sirca, S., Souder, P. A., Suleiman, R., Sulkosky, V., Sutera, C. M., Tobias, W. A., Urciuoli, G. M., Waidyawansa, B., Wojtsekhowski, B., Ye, L., Zhao, B., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

We report on parity-violating asymmetries in the nucleon resonance region measured using $5 - 6$ GeV longitudinally polarized electrons scattering off an unpolarized deuterium target. These results are the first parity-violating asymmetry data in the resonance region beyond the $\Delta(1232)$, and provide a verification of quark-hadron duality in the nucleon electroweak $\gamma Z$ interference structure functions at the (10-15)% level. The results are of particular interest to models relevant for calculating the $\gamma Z$ box-diagram corrections to elastic parity-violating electron scattering measurements., Comment: 7 pages, 1 figure, to appear in Phys. Rev. Lett

Published
2013
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25. New Measurements of the Transverse Beam Asymmetry for Elastic Electron Scattering from Selected Nuclei

Author

HAPPEX, The, Collaborations, PREX, Abrahamyan, S., Acha, A., Afanasev, A., Ahmed, Z., Albataineh, H., Aniol, K., Armstrong, D. S., Armstrong, W., Arrington, J., Averett, T., Babineau, B., Bailey, S. L., Barber, J., Barbieri, A., Beck, A., Bellini, V., Beminiwattha, R., Benaoum, H., Benesch, J., Benmokhtar, F., Bertin, P., Bielarski, T., Boeglin, W., Bosted, P., Butaru, F., Burtin, E., Cahoon, J., Camsonne, A., Canan, M., Carter, P., Chang, C. C., Cates, G. D., Chao, Y. C., Chen, C., Chen, J. P., Choi, Seonho, Chudakov, E., Cisbani, E., Craver, B., Cusanno, F., Dalton, M. M., De Leo, R., de Jager, K., Deconinck, W., Decowski, P., Deepa, D., Deng, X., Deur, A., Dutta, D., Etile, A., Ferdi, C., Feuerbach, R. J., Finn, J. M., Flay, D., Franklin, G. B., Friend, M., Frullani, S., Fuchey, E., Fuchs, S. A., Fuoti, K., Garibaldi, F., Gasser, E., Gilman, R., Giusa, A., Glamazdin, A., Glesener, L. E., Gomez, J., Gorchtein, M., Grames, J., Grimm, K., Gu, C., Hansen, O., Hansknecht, J., Hen, O., Higinbotham, D. W., Holmes, R. S., Holmstrom, T., Horowitz, C. J., Hoskins, J., Huang, J., Humensky, T. B., Hyde, C. E., Ibrahim, H., Itard, F., Jen, C. M., Jensen, E., Jiang, X., Jin, G., Johnston, S., Katich, J., Kaufman, L. J., Kelleher, A., Kliakhandler, K., King, P. M., Kolarkar, A., Kowalski, S., Kuchina, E., Kumar, K. S., Lagamba, L., Lambert, D., LaViolette, P., Leacock, J., Leckey IV, J., Lee, J. H., LeRose, J. J., Lhuillier, D., Lindgren, R., Liyanage, N., Lubinsky, N., Mammei, J., Mammoliti, F., Margaziotis, D. J., Markowitz, P., Mazouz, M., McCormick, K., McCreary, A., McNulty, D., Meekins, D. G., Mercado, L., Meziani, Z. E., Michaels, R. W., Mihovilovic, M., Moffit, B., Monaghan, P., Muangma, N., Munoz-Camacho, C., Nanda, S., Nelyubin, V., Neyret, D., Nuruzzaman, Oh, Y., Otis, K., Palmer, A., Parno, D., Paschke, K. D., Phillips, S. K., Poelker, M., Pomatsalyuk, R., Posik, M., Potokar, M., Prok, K., Puckett, A. J. R., Qian, X., Qiang, Y., Quinn, B., Rakhman, A., Reimer, P. E., Reitz, B., Riordan, S., Roche, J., Rogan, P., Ron, G., Russo, G., Saenboonruang, K., Saha, A., Sawatzky, B., Shahinyan, A., Silwal, R., Singh, J., Sirca, S., Slifer, K., Snyder, R., Solvignon, P., Souder, P. A., Sperduto, M. L., Subedi, R., Stutzman, M. L., Suleiman, R., Sulkosky, V., Sutera, C. M., Tobias, W. A., Troth, W., Urciuoli, G. M., Ulmer, P., Vacheret, A., Voutier, E., Waidyawansa, B., Wang, D., Wang, K., Wexler, J., Whitbeck, A., Wilson, R., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yim, V., Zana, L., Zhan, X., Zhang, J., Zhang, Y., Zheng, X., Ziskin, V., and Zhu, P.

Subjects
Nuclear Experiment
Abstract

We have measured the beam-normal single-spin asymmetry $A_n$ in the elastic scattering of 1-3 GeV transversely polarized electrons from $^1$H and for the first time from $^4$He, $^{12}$C, and $^{208}$Pb. For $^1$H, $^4$He and $^{12}$C, the measurements are in agreement with calculations that relate $A_n$ to the imaginary part of the two-photon exchange amplitude including inelastic intermediate states. Surprisingly, the $^{208}$Pb result is significantly smaller than the corresponding prediction using the same formalism. These results suggest that a systematic set of new $A_n$ measurements might emerge as a new and sensitive probe of the structure of heavy nuclei., Comment: 5 pages, 3 figures, accepted by PRL. v3: fixed one author name and affiliation, otherwise no change

Published
2012
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26. Weak charge form factor and radius of 208Pb through parity violation in electron scattering

Author

Horowitz, C. J., Ahmed, Z., Jen, C. -M., Rakhman, A., Souder, P. A., Dalton, M. M., Liyanage, N., Paschke, K. D., Saenboonruang, K., Silwal, R., Franklin, G. B., Friend, M., Quinn, B., Kumar, K. S., Mammei, J. M., McNulty, D., Mercado, L., Riordan, S., Wexler, J., Michaels, R. W., and Urciuoli, G. M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We use distorted wave electron scattering calculations to extract the weak charge form factor F_W(q), the weak charge radius R_W, and the point neutron radius R_n, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer q=0.475 fm$^{-1}$. We find F_W(q) =0.204 \pm 0.028 (exp) \pm 0.001 (model). We use the Helm model to infer the weak radius from F_W(q). We find R_W= 5.826 \pm 0.181 (exp) \pm 0.027 (model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in R_W from uncertainties in the surface thickness \sigma of the weak charge density. The weak radius is larger than the charge radius, implying a "weak charge skin" where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius R_n=5.751 \pm 0.175 (exp) \pm 0.026 (model) \pm 0.005 (strange) fm$, from R_W. Here there is only a very small error (strange) from possible strange quark contributions. We find R_n to be slightly smaller than R_W because of the nucleon's size. Finally, we find a neutron skin thickness of R_n-R_p=0.302\pm 0.175 (exp) \pm 0.026 (model) \pm 0.005 (strange) fm, where R_p is the point proton radius., Comment: 5 pages, 1 figure, published in Phys Rev. C. Only one change in this version: we have added one author, also to metadata

Published
2012
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27. Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering

Author

Abrahamyan, S., Ahmed, Z., Albataineh, H., Aniol, K., Armstrong, D. S., Armstrong, W., Averett, T., Babineau, B., Barbieri, A., Bellini, V., Beminiwattha, R., Benesch, J., Benmokhtar, F., Bielarski, T., Boeglin, W., Camsonne, A., Canan, M., Carter, P., Cates, G. D., Chen, C., Chen, J. -P., Hen, O., Cusanno, F., Dalton, M. M., De Leo, R., de Jager, K., Deconinck, W., Decowski, P., Deng, X., Deur, A., Dutta, D., Etile, A., Flay, D., Franklin, G. B., Friend, M., Frullani, S., Fuchey, E., Garibaldi, F., Gasser, E., Gilman, R., Giusa, A., Glamazdin, A., Gomez, J., Grames, J., Gu, C., Hansen, O., Hansknecht, J., Higinbotham, D. W., Holmes, R. S., Holmstrom, T., Horowitz, C. J., Hoskins, J., Huang, J., Hyde, C. E., Itard, F., Jen, C. -M., Jensen, E., Jin, G., Johnston, S., Kelleher, A., Kliakhandler, K., King, P. M., Kowalski, S., Kumar, K. S., Leacock, J., Leckey IV, J., Lee, J. H., LeRose, J. J., Lindgren, R., Liyanage, N., Lubinsky, N., Mammei, J., Mammoliti, F., Margaziotis, D. J., Markowitz, P., McCreary, A., McNulty, D., Mercado, L., Meziani, Z. -E., Michaels, R. W., Mihovilovic, M., Muangma, N., Muñoz-Camacho, C., Nanda, S., Nelyubin, V., Nuruzzaman, N., Oh, Y., Palmer, A., Parno, D., Paschke, K. D., Phillips, S. K., Poelker, B., Pomatsalyuk, R., Posik, M., Puckett, A. J. R., Quinn, B., Rakhman, A., Reimer, P. E., Riordan, S., Rogan, P., Ron, G., Russo, G., Saenboonruang, K., Saha, A., Sawatzky, B., Shahinyan, A., Silwal, R., Sirca, S., Slifer, K., Solvignon, P., Souder, P. A., Sperduto, M. L., Subedi, R., Suleiman, R., Sulkosky, V., Sutera, C. M., Tobias, W. A., Troth, W., Urciuoli, G. M., Waidyawansa, B., Wang, D., Wexler, J., Wilson, R., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yim, V., Zana, L., Zhan, X., Zhang, J., Zhang, Y., Zheng, X., and Zhu, P.

Subjects
Nuclear Experiment
Abstract

We report the first measurement of the parity-violating asymmetry A_PV in the elastic scattering of polarized electrons from 208Pb. A_PV is sensitive to the radius of the neutron distribution (Rn). The result A_PV = 0.656 \pm 0.060 (stat) \pm 0.014 (syst) ppm corresponds to a difference between the radii of the neutron and proton distributions Rn - Rp = 0.33 +0.16 -0.18 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus., Comment: 6 pages, 1 figure

Published
2012
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28. Upgraded photon calorimeter with integrating readout for Hall A Compton Polarimeter at Jefferson Lab

Author

Friend, M., Parno, D., Benmokhtar, F., Camsonne, A., Dalton, M., Franklin, G. B., Mamyan, V., Michaels, R., Nanda, S., Nelyubin, V., Paschke, K., Quinn, B., Rakhman, A., Souder, P., and Tobias, A.

Subjects
Physics - Instrumentation and Detectors
Abstract

The photon arm of the Compton polarimeter in Hall A of Jefferson Lab has been upgraded to allow for electron beam polarization measurements with better than 1% accuracy. The data acquisition system (DAQ) now includes an integrating mode, which eliminates several systematic uncertainties inherent in the original counting-DAQ setup. The photon calorimeter has been replaced with a Ce-doped GSO crystal, which has a bright output and fast response, and works well for measurements using the new integrating method at electron beam energies from 1 to 6 GeV., Comment: 16 pages, 15 figures

Published
2011
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29. Beam-Target Double Spin Asymmetry A_LT in Charged Pion Production from Deep Inelastic Scattering on a Transversely Polarized He-3 Target at 1.4<Q^2<2.7 GeV^2

Author

Huang, J., Allada, K., Dutta, C., Katich, J., Qian, X., Wang, Y., Zhang, Y., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, M., Ibrahim, H. F., Iodice, M., Jiang, X., Jin, G., Jones, M. K., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Muñoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qiang, Y., Rakhman, A., Ransome, R. D., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Širca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We report the first measurement of the double-spin asymmetry $A_{LT}$ for charged pion electroproduction in semi\nobreakdash-inclusive deep\nobreakdash-inelastic electron scattering on a transversely polarized $^{3}$He target. The kinematics focused on the valence quark region, $0.16

Published
2011
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30. New Precision Limit on the Strange Vector Form Factors of the Proton

Author

HAPPEX collaboration, Ahmed, Z., Allada, K., Aniol, K. A., Armstrong, D. S., Arrington, J., Baturin, P., Bellini, V., Benesch, J., Beminiwattha, R., Benmokhtar, F., Canan, M., Camsonne, A., Cates, G. D., Chen, J. -P., Chudakov, E., Cisbani, E., Dalton, M. M., de Jager, C. W., De Leo, R., Deconinck, W., Decowski, P., Deng, X., Deur, A., Dutta, C., Franklin, G. B., Friend, M., Frullani, S., Garibaldi, F., Giusa, A., Glamazdin, A., Golge, S., Grimm, K., Hansen, O., Higinbotham, D. W., Holmes, R., Holmstrom, T., Huang, J., Huang, M., Hyde, C. E., Jen, C. M., Jin, G., Jones, D., Kang, H., King, P., Kowalski, S., Kumar, K. S., Lee, J. H., LeRose, J. J., Liyanage, N., Long, E., McNulty, D., Margaziotis, D., Meddi, F., Meekins, D. G., Mercado, L., Meziani, Z. -E., Michaels, R., Munoz-Camacho, C., Mihovilovic, M., Muangma, N., Myers, K. E., Nanda, S., Narayan, A., Nelyubin, V., Nuruzzaman, Oh, Y., Pan, K., Parno, D., Paschke, K. D., Phillips, S. K., Qian, X., Qiang, Y., Quinn, B., Rakhman, A., Reimer, P. E., Rider, K., Riordan, S., Roche, J., Rubin, J., Russo, G., Saenboonruang, K., Saha, A., Sawatzky, B., Silwal, R., Sirca, S., Souder, P. A., Sperduto, M., Subedi, R., Suleiman, R., Sulkosky, V., Sutera, C. M., Tobias, W. A., Urciuoli, G. M., Waidyawansa, B., Wang, D., Wexler, J., Wilson, R., Wojtsekhowski, B., Zhan, X., Yan, X., Yao, H., Ye, L., Zhao, B., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624 GeV and beam energy E =3.48 GeV to be A_PV = -23.80 +/- 0.78 (stat) +/- 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G_E^s + 0.517 G_M^s = 0.003 +/- 0.010 (stat) +/- 0.004 (syst) +/- 0.009 (ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors., Comment: 5 pages, 3 figures

Published
2011
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31. Single Spin Asymmetries in Charged Pion Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized $^3$He Target

Author

Qian, X., Allada, K., Dutta, C., Huang, J., Katich, J., Wang, Y., Zhang, Y., Aniol, K., Annand, J. R. M., Averett, T., Benmokhtar, F., Bertozzi, W., Bradshaw, P. C., Bosted, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Chen, W., Chirapatpimol, K., Chudakov, E., Cisbani, E., Cornejo, J. C., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., De Leo, R., Deng, X., Deur, A., Ding, H., Dolph, P. A. M., Dutta, D., Fassi, L. El, Frullani, S., Gao, H., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Guo, L., Hamilton, D., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, M., Ibrahim, H. F., Iodice, M., Jiang, X., Jin, G., Jones, M. K., Kelleher, A., Kim, W., Kolarkar, A., Korsch, W., LeRose, J. J., Li, X., Li, Y., Lindgren, R., Liyanage, N., Long, E., Lu, H. -J., Margaziotis, D. J., Markowitz, P., Marrone, S., McNulty, D., Meziani, Z. -E., Michaels, R., Moffit, B., Camacho, C. Munoz, Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Osipenko, M., Parno, D., Peng, J. C., Phillips, S. K., Posik, M., Puckett, A. J. R., Qiang, Y., Rakhman, A., Ransome, R. D., Riordan, S., Saha, A., Sawatzky, B., Schulte, E., Shahinyan, A., Shabestari, M. H., Širca, S., Stepanyan, S., Subedi, R., Sulkosky, V., Tang, L. -G., Tobias, A., Urciuoli, G. M., Vilardi, I., Wang, K., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y. -W., Zhao, B., Zheng, X., Zhu, L., Zhu, X., and Zong, X.

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

We report the first measurement of target single spin asymmetries in the semi-inclusive $^3{He}(e,e'\pi^\pm)X$ reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.14 $< x <$ 0.34 with 1.3 $

Published
2011
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32. High Precision Measurement of the Proton Elastic Form Factor Ratio $\mu_pG_E/G_M$ at low $Q^2$

Author

Zhan, X., Allada, K., Armstrong, D. S., Arrington, J., Bertozzi, W., Boeglin, W., Chen, J. -P., Chirapatpimol, K., Choi, S., Chudakov, E., Cisbani, E., Decowski, P., Dutta, C., Frullani, S., Fuchey, E., Garibaldi, F., Gilad, S., Gilman, R., Glister, J., Hafidi, K., Hahn, B., Hansen, J. -O., Higinbotham, D. W., Holmstrom, T., Holt, R. J., Huang, J., Huber, G. M., Itard, F., de Jager, C. W., Jiang, X., Johnson, J., Katich, J., de Leo, R., LeRose, J. J., Lindgren, R., Long, E., Margaziotis, D. J., Beck, S. May-Tal, Meekins, D., Michaels, R., Moffit, B., Norum, B. E., Olson, M., Piasetzky, E., Pomerantz, I., Protopopescu, D., Qian, X., Qiang, Y., Rakhman, A., Ransome, R. D., Reimer, P. E., Reinhold, J., Riordan, S., Ron, G., Saha, A., Sarty, A. J., Sawatzky, B., Schulte, E. C., Shabestari, M., Shahinyan, A., Sirca, S., Solvignon, P., Sparveris, N. F., Strauch, S., Subedi, R., Sulkosky, V., Vilardi, I., Wang, Y., Wojtsekhowski, B., Ye, Z., and Zhang, Y.

Subjects
Nuclear Experiment
Abstract

We report a new, high-precision measurement of the proton elastic form factor ratio \mu_p G_E/G_M for the four-momentum transfer squared Q^2 = 0.3-0.7 (GeV/c)^2. The measurement was performed at Jefferson Lab (JLab) in Hall A using recoil polarimetry. With a total uncertainty of approximately 1%, the new data clearly show that the deviation of the ratio \mu_p G_E/G_M from unity observed in previous polarization measurements at high Q^2 continues down to the lowest Q^2 value of this measurement. The updated global fit that includes the new results yields an electric (magnetic) form factor roughly 2% smaller (1% larger) than the previous global fit in this Q^2 range. We obtain new extractions of the proton electric and magnetic radii, which are ^(1/2)=0.875+/-0.010 fm and ^(1/2)=0.867+/-0.020 fm. The charge radius is consistent with other recent extractions based on the electron-proton interaction, including the atomic hydrogen Lamb shift measurements, which suggests a missing correction in the comparison of measurements of the proton charge radius using electron probes and the recent extraction from the muonic hydrogen Lamb shift., Comment: 12 pages, 3 figures

Published
2011
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