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415 results on '"Aniol, K. A."'

1. Inclusive studies of two- and three-nucleon short-range correlations in $^3$H and $^3$He

Author

Li, S., Santiesteban, S. N., Arrington, J., Cruz-Torres, R., Kurbany, L., Abrams, D., Alsalmi, S., Androic, D., Aniol, K., Averett, T., Gayoso, C. Ayerbe, Bane, J., Barcus, S., Barrow, J., Beck, A., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Bulumulla, D., Camsonne, A., Castellanos, J., Chen, J., Chen, J-P., Chrisman, D., Christy, M. E., Clarke, C., Covrig, S., Craycraft, K., Day, D., Dutta, D., Fuchey, E., Gal, C., Garibaldi, F., Gautam, T. N., Gogami, T., Gomez, J., Guéye, P., Habarakada, A., Hague, T. J., Hansen, J. O., Hauenstein, F., Henry, W., Higinbotham, D. W., Holt, R. J., Hyde, C., Itabashi, K., Kaneta, M., Karki, A., Katramatou, A. T., Keppel, C. E., Khachatryan, M., Khachatryan, V., King, P. M., Korover, I., Kutz, T., Lashley-Colthirst, N., Li, W. B., Liu, H., Liyanage, N., Long, E., Mammei, J., Markowitz, P., McClellan, R. E., Meddi, F., Meekins, D., Beck, S. Mey-Tal, Michaels, R., Mihovilovič, M., Moyer, A., Nagao, S., Nelyubin, V., Nguyen, D., Nycz, M., Olson, M., Ou, L., Owen, V., Palatchi, C., Pandey, B., Papadopoulou, A., Park, S., Paul, S., Petkovic, T., Pomatsalyuk, R., Premathilake, S., Punjabi, V., Ransome, R. D., Reimer, P. E., Reinhold, J., Riordan, S., Roche, J., Rodriguez, V. M., Schmidt, A., Schmookler, B., Segarra, E. P., Shahinyan, A., Širca, S., Slifer, K., Solvignon, P., Su, T., Suleiman, R., Szumila-Vance, H., Tang, L., Tian, Y., Tireman, W., Tortorici, F., Toyama, Y., Uehara, K., Urciuoli, G. M., Votaw, D., Williamson, J., Wojtsekhowski, B., Wood, S., Ye, Z. H., Zhang, J., and Zheng, X.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Inclusive electron scattering at carefully chosen kinematics can isolate scattering from short-range correlations (SRCs), produced through hard, short-distance interactions of nucleons in the nucleus. Because the two-nucleon (2N) SRCs arise from the same N-N interaction in all nuclei, the cross section in the SRC-dominated regime is identical up to an overall scaling factor, and the A/2H cross section ratio is constant in this region. This scaling behavior has been used to identify SRC dominance and to map out the contribution of SRCs for a wide range of nuclei. We examine this scaling behavior at lower momentum transfers using new data on $^2$H, $^3$H, and $^3$He which show that the scaling region is larger than in heavy nuclei. Based on the improved scaling, especially for $^3$H/$^3$He, we examine the ratios at kinematics where three-nucleon SRCs may play an important role. The data for the largest initial nucleon momenta are consistent with isolation of scattering from 3N-SRCs, and suggest that the very-highest momentum nucleons in $^3$He have a nearly isospin-independent momentum configuration, or a small enhancement of the proton distribution.

Published
2024

2. Novel Measurement of the Neutron Magnetic Form Factor from A=3 Mirror Nuclei

Author

Santiesteban, SN, Li, S, Abrams, D, Alsalmi, S, Androic, D, Aniol, K, Arrington, J, Averett, T, Gayoso, C Ayerbe, Bane, J, Barcus, S, Barrow, J, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Camsonne, A, Castellanos, J, Chen, J, Chen, J-P, Chrisman, D, Christy, ME, Clarke, C, Covrig, S, Cruz-Torres, R, Day, D, Dutta, D, Fuchey, E, Gal, C, Garibaldi, F, Gautam, TN, Gogami, T, Gomez, J, Guèye, P, Hague, TJ, Hansen, JO, Hauenstein, F, Henry, W, Higinbotham, DW, Holt, RJ, Hyde, C, Itabashi, K, Kaneta, M, Karki, A, Katramatou, AT, Keppel, CE, King, PM, Kurbany, L, Kutz, T, Lashley-Colthirst, N, Li, WB, Liu, H, Liyanage, N, Long, E, Lovato, A, Mammei, J, Markowitz, P, McClellan, RE, Meddi, F, Meekins, D, Michaels, R, Mihovilovič, M, Moyer, A, Nagao, S, Nguyen, D, Nycz, M, Olson, M, Ou, L, Owen, V, Palatchi, C, Pandey, B, Papadopoulou, A, Park, S, Petkovic, T, Premathilake, S, Punjabi, V, Ransome, RD, Reimer, PE, Reinhold, J, Riordan, S, Rocco, N, Rodriguez, VM, Schmidt, A, Schmookler, B, Segarra, EP, Shahinyan, A, Širca, S, Slifer, K, Solvignon, P, Su, T, Suleiman, R, Tang, L, Tian, Y, Tireman, W, Tortorici, F, Toyama, Y, Uehara, K, Urciuoli, GM, and Votaw, D

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Jefferson Lab Hall A Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei ^{3}H and ^{3}He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, 0.6

Published
2024

3. Electroproduction of the Lambda/Sigma^0 hyperons at Q^2~0.5 (GeV/c)^2 at forward angles

Author

Okuyama, K., Itabashi, K., Nagao, S., Nakamura, S. N., Suzuki, K. N., Gogami, T., Pandey, B., Tang, L., Bydžovský, P., Skoupil, D., Mart, T., Abrams, D., Akiyama, T., Androic, D., Aniol, K., Gayoso, C. Ayerbe, Bane, J., Barcus, S., Barrow, J., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Camsonne, A., Castellanos, J., Chen, J-P., Chen, J., Covrig, S., Chrisman, D., Cruz-Torres, R., Das, R., Fuchey, E., Gnanvo, K., Garibaldi, F., Gautam, T., Gomez, J., Gueye, P., Hague, T. J., Hansen, O., Henry, W., Hauenstein, F., Higinbotham, D. W., Hyde, C. E., Kaneta, M., Keppel, C., Kutz, T., Lashley-Colthirst, N., Li, S., Liu, H., Mammei, J., Markowitz, P., McClellan, R. E., Meddi, F., Meekins, D., Michaels, R., Mihovilovič, M., Moyer, A., Nguyen, D., Nycz, M., Owen, V., Palatchi, C., Park, S., Petkovic, T., Premathilake, S., Reimer, P. E., Reinhold, J., Riordan, S., Rodriguez, V., Samanta, C., Santiesteban, S. N., Sawatzky, B., Širca, S., Slifer, K., Su, T., Tian, Y., Toyama, Y., Uehara, K., Urciuoli, G. M., Votaw, D., Williamson, J., Wojtsekhowski, B., Wood, S. A., Yale, B., Ye, Z., Zhang, J., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

In 2018, the E12-17-003 experiment was conducted at the Thomas Jefferson National Accelerator Facility (JLab) to explore the possible existence of an nnLambda state in the reconstructed missing mass distribution from a tritium gas target [K. N. Suzuki et al., Prog. Theor. Exp. Phys. 2022, 013D01 (2022), B. Pandey et al., Phys. Rev. C 105, L051001 (2022)]. As part of this investigation, data was also collected using a gaseous hydrogen target, not only for a precise absolute mass scale calibration but also for the study of Lambda/Sigma^0 electroproduction. This dataset was acquired at Q^2~0.5 (GeV/c)^2, W=2.14 GeV, and theta_{gamma K}^{c.m.}~8 deg. It covers forward angles where photoproduction data is scarce and a low-Q^2 region that is of interest for hypernuclear experiments. On the other hand, this kinematic region is at a slightly higher Q^2 than previous hypernuclear experiments, thus providing crucial information for understanding the Q^2 dependence of the differential cross sections for Lambda/Sigma^0 hyperon electroproduction. This paper reports on the Q^2 dependence of the differential cross section for the e + p -> e' + K^+ + Lambda/Sigma^0 reaction in the 0.2-0.8 (GeV/c)^2, and provides comparisons with the currently available theoretical models., Comment: 11 pages, 15 figures

Published
2024

4. A novel measurement of the neutron magnetic form factor from A=3 mirror nuclei

Author

Santiesteban, S. N., Li, S., Abrams, D., Alsalmi, S., Androic, D., Aniol, K., Arrington, J., Averett, T., Gayoso, C. Ayerbe, Bane, J., Barcus, S., Barrow, J., Beck, A., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Camsonne, A., Castellanos, J., Chen, J., Chen, J-P., Chrisman, D., Christy, M. E., Clarke, C., Covrig, S., Cruz-Torres, R., Day, D., Dutta, D., Fuchey, E., Gal, C., Garibaldi, F., Gautam, T. N., Gogami, T., Gomez, J., Gueye, P., Hague, T. J., Hansen, J. O., Hauenstein, F., Henry, W., Higinbotham, D. W., Holt, R. J., Hyde, C., Itabashi, K., Kaneta, M., Karki, A., Katramatou, A. T., Keppel, C. E., King, P. M., Kurbany, L., Kutz, T., Lashley-Colthirst, N., Li, W. B., Liu, H., Liyanage, N., Long, E., Lovato, A., Mammei, J., Markowitz, P., McClellan, R. E., Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Moyer, A., Nagao, S., Nguyen, D., Nycz, M., Olson, M., Ou, L., Owen, V., Palatchi, C., Pandey, B., Papadopoulou, A., Park, S., Petkovic, T., Premathilake, 6 S., Punjabi, V., Ransome, R. D., Reimer, P. E., Reinhold, J., Riordan, S., Rocco, N., Rodriguez, V. M., Schmidt, A., Schmookler, B., Segarra, E. P., Shahinyan, A., Sirca, S., Slifer, K., Solvignon, P., Su, T., Suleiman, R., Tang, L., Tian, Y., Tireman, W., Tortorici, F., Toyama, Y., Uehara, K., Urciuoli, G. M., Votaw, D., Williamson, J., Wojtsekhowski, B., Wood, S., Ye, Z. H., Zhang, J., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei $^3$H and $^3$He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, $0.6

Published
2023

5. Revealing the short-range structure of the 'mirror nuclei' $^3$H and $^3$He

Author

Li, S., Cruz-Torres, R., Santiesteban, N., Ye, Z. H., Abrams, D., Alsalmi, S., Androic, D., Aniol, K., Arrington, J., Averett, T., Gayoso, C. Ayerbe, Bane, J., Barcus, S., Barrow, J., Beck, A., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Bulumulla, D., Camsonne, A., Castellanos, J., Chen, J., Chen, J-P., Chrisman, D., Christy, M. E., Clarke, C., Covrig, S., Craycraft, K., Day, D., Dutta, D., Fuchey, E., Gal, C., Garibaldi, F., Gautam, T. N., Gogami, T., Gomez, J., Guèye, P., Habarakada, A., Hague, T. J., Hansen, J. O., Hauenstein, F., Henry, W., Higinbotham, D. W., Holt, R. J., Hyde, C., Itabashi, T., Kaneta, M., Karki, A., Katramatou, A. T., Keppel, C. E., Khachatryan, M., Khachatryan, V., King, P. M., Korover, I., Kurbany, L., Kutz, T., Lashley-Colthirst, N., Li, W. B., Liu, H., Liyanage, N., Long, E., Mammei, J., Markowitz, P., McClellan, R. E., Meddi, F., Meekins, D., Beck, S. Mey-Tal, Michaels, R., Mihovilovič, M., Moyer, A., Nagao, S., Nelyubin, V., Nguyen, D., Nycz, M., Olson, M., Ou, L., Owen, V., Palatchi, C., Pandey, B., Papadopoulou, A., Park, S., Paul, S., Petkovic, T., Pomatsalyuk, R., Premathilake, S., Punjabi, V., Ransome, R. D., Reimer, P. E., Reinhold, J., Riordan, S., Roche, J., Rodriguez, V. M., Schmidt, A., Schmookler, B., Segarra, E. P., Shahinyan, A., Slifer, K., Solvignon, P., Širca, S., Su, T., Suleiman, R., Szumila-Vance, H., Tang, L., Tian, Y., Tireman, W., Tortorici, F., Toyama, Y., Uehara, K., Urciuoli, G. M., Votaw, D., Williamson, J., Wojtsekhowski, B., Wood, S., Zhang, J., and Zheng, X.

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

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough together to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly-energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure and mapping out the strength and isospin structure (neutron-proton vs proton-proton pairs) of these virtual excitations is thus critical input for modeling a range of nuclear, particle, and astrophysics measurements. Hitherto measurements used two-nucleon knockout or ``triple-coincidence'' reactions to measure the relative contribution of np- and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurementsshow that SRCs are almost exclusively np pairs, but had limited statistics and required large model-dependent final-state interaction (FSI) corrections. We report on the first measurement using inclusive scattering from the mirror nuclei $^3$H and $^3$He to extract the np/pp ratio of SRCs in the A=3 system. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a dramatic deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for $^3$He and $^3$H. Understanding these results will improve our understanding of the short-range part of the N-N interaction.

Published
2022
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6. Precision Determination of the Neutral Weak Form Factor of $^{48}$Ca

Author

Adhikari, D., Albataineh, H., Androic, D., Aniol, K. A., Armstrong, D. S., Averett, T., Gayoso, C. Ayerbe, Barcus, S. K., Bellini, V., Beminiwattha, R. S., Benesch, J. F., Bhatt, H., Pathak, D. Bhatta, Bhetuwal, D., Blaikie, B., Boyd, J., Campagna, Q., Camsonne, A., Cates, G. D., Chen, Y., Clarke, C., Cornejo, J. C., Dusa, S. Covrig, Dalton, M. M., Datta, P., Deshpande, A., Dutta, D., Feldman, C., Fuchey, E., Gal, C., Gaskell, D., Gautam, T., Gericke, M., Ghosh, C., Halilovic, I., Hansen, J. -O., Hassan, O., Hauenstein, F., Henry, W., Horowitz, C. J., Jantzi, C., Jian, S., Johnston, S., Jones, D. C., Kakkar, S., Katugampola, S., Keppel, C., King, P. M., King, D. E., Kumar, K. S., Kutz, T., Lashley-Colthirst, N., Leverick, G., Liu, H., Liyanage, N., Mammei, J., Mammei, R., McCaughan, 23 M., McNulty, D., Meekins, D., Metts, C., Michaels, R., Mihovilovic, M., Mondal, M. M., Napolitano, J., Narayan, A., Nikolaev, D., Owen, V., Palatchi, C., Pan, J., Pandey, B., Park, S., Paschke, K. D., Petrusky, M., Pitt, M. L., Premathilake, S., Quinn, B., Radloff, R., Rahman, S., Rashad, M. N. H., Rathnayake, A., Reed, B. T., Reimer, P. E., Richards, R., Riordan, S., Roblin, Y. R., Seeds, S., Shahinyan, A., Souder, P., Thiel, M., Tian, Y., Urciuoli, G. M., Wertz, E. W., Wojtsekhowski, B., Yale, B., Ye, T., Yoon, A., Xiong, W., Zec, A., Zhang, W., Zhang, J., and Zheng, X.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We report a precise measurement of the parity-violating asymmetry $A_{\rm PV}$ in the elastic scattering of longitudinally polarized electrons from $^{48}{\rm Ca}$. We measure $A_{\rm PV} =2668\pm 106\ {\rm (stat)}\pm 40\ {\rm (syst)}$ parts per billion, leading to an extraction of the neutral weak form factor $F_{\rm W} (q=0.8733$ fm$^{-1}) = 0.1304 \pm 0.0052 \ {\rm (stat)}\pm 0.0020\ {\rm (syst)}$ and the charge minus the weak form factor $F_{\rm ch} - F_{\rm W} = 0.0277\pm 0.0055$. The resulting neutron skin thickness $R_n-R_p=0.121 \pm 0.026\ {\rm (exp)} \pm 0.024\ {\rm (model)}$~fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter., Comment: 8 pages, 5 figures Replace 6-16-22: included ancillary files, corrected errors in references, author affiliations. Small text changes for clarity

Published
2022
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7. The Proton Spin Structure Function $g_2$ and Generalized Polarizabilities in the Strong QCD Regime

Author

Ruth, D., Zielinski, R., Gu, C., Allada, M., Badman, T., Huang, M., Liu, J., Zhu, P., Allada, K., Zhang, J., Camsonne, A., Chen, J. P., Slifer, K., Aniol, K., Annand, J., Arrington, J., Averett, T., Baghdasaryan, H., Bellini, V., Boeglin, W., Brock, J., Carlin, C., Chen, C., Cisbani, E., Crabb, D., Daniel, A., Day, D., Duve, R., Fassi, L. El, Friedman, M., Fuchey, E., Gao, H., Gilman, R., Glamazdin, S., Gueye, P., Hafez, M., Han, Y., Hansen, O., Shabestari, M. Hashemi, Hen, O., Higinbotham, D., Horn, T., Iqbal, S., Jensen, E., Kang, H., Keith, C. D., Kelleher, A., Keller, D., Khanal, H., Korover, I., Kumbartzki, G., Li, W., Lichtenstadt, J., Lindgren, R., Long, E., Malace, S., Markowitz, P., Maxwell, J., Meekins, D. M., Meziani, Z. E., McLean, C., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Munoz, Musson, J., Myers, K., Oh, Y., Carmignotto, M. Pannunzio, Perdrisat, C., Phillips, S., Piasetzky, E., Pierce, J., Punjabi, V., Qiang, Y., Reimer, P. E., Roblin, Y., Ron, G., Rondon, O., Russo, G., Saenboonruang, K., Sawatzky, B., Shahinyan, A., Shneor, R., Sjoegren, J., Solvignon-Slifer, P., Sparveris, N., Sulkosky, V., Wesselmann, F., Yan, W., Yang, H., Yao, H., Ye, Z., Yurov, M., Zhang, Y., Zhao, Y. X., and Zheng, X.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The strong interaction is not well understood at low energy, or for interactions with low momentum transfer $Q^2$, but one of the clearest insights we have comes from Chiral Perturbation Theory ($\chi$PT). This effective treatment gives testable predictions for the nucleonic generalized polarizabilities -- fundamental quantities describing the nucleon's response to an external field. We have measured the proton's generalized spin polarizabilities in the region where $\chi$PT is expected to be valid. Our results include the first ever data for the transverse-longitudinal spin polarizability $\delta_{LT}$, and also extend the coverage of the polarizability $\bar{d_2}$ to very low $Q^2$ for the first time. These results were extracted from moments of the structure function $g_2$, a quantity which characterizes the internal spin structure of the proton. Our experiment ran at Jefferson Lab using a polarized electron beam and a polarized solid ammonia (NH$_3$) target. The $\delta_{LT}$ polarizability has remained a challenging quantity for $\chi$PT to reproduce, despite its reduced sensitivity to higher resonance contributions; recent competing calculations still disagree with each other and also diverge from the measured neutron data at very low $Q^2$. Our proton results provide discriminating power between existing calculations, and will help provide a better understanding of this strong QCD regime.

Published
2022

8. Proton spin structure and generalized polarizabilities in the strong quantum chromodynamics regime

Author

Ruth, D, Zielinski, R, Gu, C, Allada (Cummings), M, Badman, T, Huang, M, Liu, J, Zhu, P, Allada, K, Zhang, J, Camsonne, A, Chen, J-P, Slifer, K, Aniol, K, Annand, J, Arrington, J, Averett, T, Baghdasaryan, H, Bellini, V, Boeglin, W, Brock, J, Carlin, C, Chen, C, Cisbani, E, Crabb, D, Daniel, A, Day, D, Duve, R, Fassi, L El, Friedman, M, Fuchey, E, Gao, H, Gilman, R, Glamazdin, S, Gueye, P, Hafez, M, Han, Y, Hansen, O, Shabestari, M Hashemi, Hen, O, Higinbotham, D, Horn, T, Iqbal, S, Jensen, E, Kang, H, Keith, CD, Kelleher, A, Keller, D, Khanal, H, Korover, I, Kumbartzki, G, Li, W, Lichtenstadt, J, Lindgren, R, Long, E, Malace, S, Markowitz, P, Maxwell, J, Meekins, DM, Meziani, ZE, McLean, C, Michaels, R, Mihovilovič, M, Muangma, N, Camacho, C Munoz, Musson, J, Myers, K, Oh, Y, Carmignotto, M Pannunzio, Perdrisat, C, Phillips, S, Piasetzky, E, Pierce, J, Punjabi, V, Qiang, Y, Reimer, PE, Roblin, Y, Ron, G, Rondon, O, Russo, G, Saenboonruang, K, Sawatzky, B, Shahinyan, A, Shneor, R, Širca, S, Sjoegren, J, Solvignon-Slifer, P, Sparveris, N, Sulkosky, V, Wesselmann, F, Yan, W, Yang, H, Yao, H, Ye, Z, Yurov, M, Zhang, Y, Zhao, YX, and Zheng, X

Subjects
Mathematical Sciences, Physical Sciences, Fluids & Plasmas
Abstract

The strong interaction is not well understood at low energies or for interactions with low momentum transfer. Chiral perturbation theory gives testable predictions for the nucleonic generalized polarizabilities, which are fundamental quantities describing the nucleon’s response to an external field. We report a measurement of the proton’s generalized spin polarizabilities extracted with a polarized electron beam and a polarized solid ammonia target in the region where chiral perturbation theory is expected to be valid. The investigated structure function g2 characterizes the internal spin structure of the proton. From its moments, we extract the longitudinal–transverse spin polarizability δLT and twist-3 matrix element and polarizability d2¯. Our results provide discriminating power between existing chiral perturbation theory calculations and will help provide a better understanding of this strong quantum chromodynamics regime.

Published
2022

9. Deeply virtual Compton scattering cross section at high Bjorken $x_B$

Author

Georges, F., Rashad, M. N. H., Stefanko, A., Dlamini, M., Karki, B., Ali, S. F., Lin, P-J., Ko, H-S, Israel, N., Adikaram, D., Ahmed, Z., Albataineh, H., Aljawrneh, B., Allada, K., Allison, S., Alsalmi, S., Androic, D., Aniol, K., Annand, J., Atac, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Bartlett, K., Bellini, V., Beminiwattha, R., Bericic, J., Biswas, D., Brash, E., Bulumulla, D., Campbell, J., Camsonne, A., Carmignotto, M., Castellano, J., Chen, C., Chen, J-P., Chetry, T., Christy, M. E., Cisbani, E., Clary, B., Cohen, E., Compton, N., Cornejo, J. C., Dusa, S. Covrig, Crowe, B., Danagoulian, S., Danley, T., De Persio, F., Deconinck, W., Defurne, M., Desnault, C., Di, D., Duer, M., Duran, B., Ent, R., Fanelli, C., Franklin, G., Fuchey, E., Gal, C., Gaskell, D., Gautam, T., Glamazdin, O., Gnanvo, K., Gray, V. M., Gu, C., Hague, T., Hamad, G., Hamilton, D., Hamilton, K., Hansen, O., Hauenstein, F., Henry, W., Higinbotham, D. W., Holmstrom, T., Horn, T., Huang, Y., Huber, G. M., Hyde, C., Ibrahim, H., Jen, C-M., Jin, K., Jones, M., Kabir, A., Keppel, C., Khachatryan, V., King, P. M., Li, S., Li, W. B., Liu, J., Liu, H., Liyanage, A., Magee, J., Malace, S., Mammei, J., Markowitz, P., McClellan, E., Mazouz, M., Meddi, F., Meekins, D., Mesik, K., Michaels, R., Mkrtchyan, A., Montgomery, R., Camacho, C. Muñoz, Myers, L. S., Nadel-Turonski, P., Nazeer, S. J., Nelyubin, V., Nguyen, D., Nuruzzaman, N., Nycz, M., Obretch, O. F., Ou, L., Palatchi, C., Pandey, B., Park, S., Park, K., Peng, C., Pomatsalyuk, R., Pooser, E., Puckett, A. J. R., Punjabi, V., Quinn, B., Rahman, S., Reimer, P. E., Roche, J., Sapkota, I., Sarty, A., Sawatzky, B., Saylor, N. H., Schmookler, B., Shabestari, M. H., Shahinyan, A., Sirca, S., Smith, G. R., Sooriyaarachchilage, S., Sparveris, N., Spies, R., Su, T., Subedi, A., Sulkosky, V., Sun, A., Thorne, L., Tian, Y., Ton, N., Tortorici, F., Trotta, R., Urciuoli, G. M., Voutier, E., Waidyawansa, B., Wang, Y., Wojtsekhowski, B., Wood, S., Yan, X., Ye, L., Ye, Z., Yero, C., Zhang, J., Zhao, Y., and Zhu, P.

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

We report high-precision measurements of the Deeply Virtual Compton Scattering (DVCS) cross section at high values of the Bjorken variable $x_B$. DVCS is sensitive to the Generalized Parton Distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton Form Factors (CFFs) of the nucleon as a function of $x_B$, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.

Published
2022
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10. Revealing the short-range structure of the mirror nuclei 3H and 3He

Author

Li, S, Cruz-Torres, R, Santiesteban, N, Ye, ZH, Abrams, D, Alsalmi, S, Androic, D, Aniol, K, Arrington, J, Averett, T, Gayoso, C Ayerbe, Bane, J, Barcus, S, Barrow, J, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, J, Chen, J-P, Chrisman, D, Christy, ME, Clarke, C, Covrig, S, Craycraft, K, Day, D, Dutta, D, Fuchey, E, Gal, C, Garibaldi, F, Gautam, TN, Gogami, T, Gomez, J, Guèye, P, Habarakada, A, Hague, TJ, Hansen, JO, Hauenstein, F, Henry, W, Higinbotham, DW, Holt, RJ, Hyde, C, Itabashi, T, Kaneta, M, Karki, A, Katramatou, AT, Keppel, CE, Khachatryan, M, Khachatryan, V, King, PM, Korover, I, Kurbany, L, Kutz, T, Lashley-Colthirst, N, Li, WB, Liu, H, Liyanage, N, Long, E, Mammei, J, Markowitz, P, McClellan, RE, Meddi, F, Meekins, D, Beck, S Mey-Tal, Michaels, R, Mihovilovič, M, Moyer, A, Nagao, S, Nelyubin, V, Nguyen, D, Nycz, M, Olson, M, Ou, L, Owen, V, Palatchi, C, Pandey, B, Papadopoulou, A, Park, S, Paul, S, Petkovic, T, Pomatsalyuk, R, Premathilake, S, Punjabi, V, Ransome, RD, Reimer, PE, Reinhold, J, Riordan, S, Roche, J, Rodriguez, VM, Schmidt, A, Schmookler, B, Segarra, EP, Shahinyan, A, Slifer, K, Solvignon, P, and Širca, S

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, General Science & Technology
Abstract

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure1-3, and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements3-5. Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements6-8 have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction.

Published
2022

11. New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering Over a Range of Spin-0 Nuclei

Author

PREX, Collaborations, CREX, Adhikari, D., Albataineh, H., Androic, D., Aniol, K., Armstrong, D. S., Averett, T., Gayoso, C. Ayerbe, Barcus, S., Bellini, V., Beminiwattha, R. S., Benesch, J. F., Bhatt, H., Pathak, D. Bhatta, Bhetuwal, D., Blaikie, B., Boyd, J., Campagna, Q., Camsonne, A., Cates, G. D., Chen, Y., Clarke, C., Cornejo, J. C., Dusa, S. Covrig, Dalton, M. M., Datta, P., Deshpande, A., Dutta, D., Feldman, C., Fuchey, E., Gal, C., Gaskell, D., Gautam, T., Gericke, M., Ghosh, C., Halilovic, I., Hansen, J. -O., Hauenstein, F., Henry, W., Horowitz, C. J., Jantzi, C., Jian, S., Johnston, S., Jones, D. C., Karki, B., Kakkar, S., Katugampola, S., Keppel, C. E., King, P. M., King, D. E., Knauss, M., Kumar, K. S., Kutz, T., Lashley-Colthirst, N., Leverick, G., Liu, H., Liyange, N., Malace, S., Mammei, J., Mammei, R., McCaughan, M., McNulty, D., Meekins, D., Metts, C., Michaels, R., Mihovilovic, M., Mondal, M. M., Napolitano, J., Nikolaev, D., Rashad, M. N. H., Owen, V., Palatchi, C., Pan, J., Pandey, B., Park, S., Paschke, K. D., Petrusky, M., Pitt, M. L., Premathilake, S., Puckett, A. J. R., Quinn, B., Radloff, R., Rahman, S., Rathnayake, A., Reed, B. T., Reimer, P. E., Richards, R., Riordan, S., Roblin, Y., Seeds, S., Shahinyan, A., Souder, P. A., Tang, L., Thiel, M., Tian, Y., Urciuoli, G. M., Wertz, E. W., Wojtsekhowski, B., Xiong, W., Yale, B., Ye, T., Zec, A., Zhang, W., Zhang, J., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

We report precision determinations of the beam normal single spin asymmetries ($A_n$) in the elastic scattering of 0.95 and 2.18~GeV electrons off $^{12}$C, $^{40}$Ca, $^{48}$Ca, and $^{208}$Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of $A_n$ for $^{40}$Ca and $^{48}$Ca are found to be similar to that of $^{12}$C, consistent with expectations thus demonstrating the validity of theoretical calculations for nuclei with Z~$\leq20$. We also report $A_n$ for $^{208}$Pb at two new momentum transfers (Q$^2$) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the $Z\leq 20$ nuclei. These data confirm our basic understanding of the underlying dynamics that govern $A_n$ for nuclei containing $\lesssim 50$ nucleons, but point to the need for further investigation to understand the unusual $A_n$ behaviour discovered for scattering off $^{208}$Pb., Comment: 7 pages, 2 figures

Published
2021
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12. The cross-section measurement for the $^3{\textrm H}(e,e'K^+)nn\Lambda$ reaction

Author

Suzuki, K. N., Gogami, T., Pandey, B., Itabashi, K., Nagao, S., Okuyama, K., Nakamura, S. N., Tang, L., Abrams, D., Akiyama, T., Androic, D., Aniol, K., Gayoso, C. Ayerbe, Bane, J., Barcus, S., Barrow, J., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Camsonne, A., Castellanos, J., Chen, J-P., Chen, J., Covrig, S., Chrisman, D., Cruz-Torres, R., Das, R., Fuchey, E., Gnanvo, K., Garibaldi, F., Gautam, T., Gomez, J., Gueye, P., Hague, T. J., Hansen, O., Henry, W., Hauenstein, F., Higinbotham, D. W., Hyde, C. E., Kaneta, M., Keppel, C., Kutz, T., Lashley-Colthirst, N., Li, S., Liu, H., Mammei, J., Markowitz, P., McClellan, R. E., Meddi, F., Meekins, D., Michaels, R., Mihovilovič, M., Moyer, A., Nguyen, D., Nycz, M., Owen, V., Palatchi, C., Park, S., Petkovic, T., Premathilake, S., Reimer, P. E., Reinhold, J., Riordan, S., Rodriguez, V., Samanta, C., Santiesteban, S. N., Sawatzky, B., Širca, S., Slifer, K., Su, T., Tian, Y., Toyama, Y., Uehara, K., Urciuoli, G. M., Votaw, D., Williamson, J., Wojtsekhowski, B., Wood, S. A., Yale, B., Ye, Z., Zhang, J., and Zheng, X.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The small binding energy of the hypertrition leads to predictions of non-existence of bound hypernuclei for isotriplet three-body systems such as $nn\Lambda$. However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound $nn\Lambda$ state. The $nn\Lambda$ state was sought by missing-mass spectroscopy via the $(e,e'K^+)$ reaction at Jefferson Lab's experimental Hall A. The present experiment has higher sensitivity to the $nn\Lambda$-state investigation in terms of better precision by a factor of about three. The analysis shown in this article focuses on the derivation of the reaction cross-section for the $^3{\rm{H}}(\gamma^{*},K^+)\textrm{X}$ reaction. Events that were detected in an acceptance, where a Monte Carlo simulation could reproduce the data well ($|\delta p/p| < 4\%$), were analyzed to minimize the systematic uncertainty. No significant structures were observed with the acceptance cuts, and the upper limits of the production cross-section of the $nn\Lambda$ state were obtained to be $21$ and $31~\rm{nb/sr}$ at the $90\%$ confidence level when theoretical predictions of $(-B_{\Lambda}, \Gamma) = (0.25,0.8)$ and $(0.55, 4.7)$ MeV, respectively, were assumed. The cross-section result provides valuable information for examining the existence of $nn\Lambda$., Comment: 27 pages, 12 figures

Published
2021
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13. Probing for high-momentum protons in He4 via the He4(e,e′p)X reactions

Author

Iqbal, S, Benmokhtar, F, Ivanov, M, See, N, Aniol, K, Higinbotham, DW, Boyd, C, Gadsby, A, Goodwill, JS, Finton, D, Boyer, A, Gilad, S, Saha, A, Udias, JM, 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, MM, 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, Guèye, 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, DJ, 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, PE, 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, JW, and Weinstein, LB

Subjects
Nuclear and Plasma Physics, Physical Sciences, Nuclear and plasma physics
Abstract

Experimental cross sections for the He4(e,e′p)X reactions in the missing energy range from 0.017 to 0.022 GeV and up to a missing momentum of 0.632 GeV/c at xB=1.24 and Q2=2 (GeV/c)2 are reported. The data are compared to relativistic distorted-wave impulse approximation calculations for the He4(e,e′p)H3 channel. Significantly more events are observed for pm≥0.45 GeV/c than are predicted by the theoretical model, and striking fluctuations in the ratio of data to the theoretical model around pm=0.3GeV/c are possible signals of initial-state multinucleon correlations.

Published
2022

14. Deeply Virtual Compton Scattering Cross Section at High Bjorken x_{B}.

Author

Georges, F, Rashad, MNH, Stefanko, A, Dlamini, M, Karki, B, Ali, SF, Lin, P-J, Ko, H-S, Israel, N, Adikaram, D, Ahmed, Z, Albataineh, H, Aljawrneh, B, Allada, K, Allison, S, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Atac, H, Averett, T, Ayerbe Gayoso, C, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Biswas, D, Brash, E, Bulumulla, D, Campbell, J, Camsonne, A, Carmignotto, M, Castellano, J, Chen, C, Chen, J-P, Chetry, T, Christy, ME, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Covrig Dusa, S, Crowe, B, Danagoulian, S, Danley, T, De Persio, F, Deconinck, W, Defurne, M, Desnault, C, Di, D, Duer, M, Duran, B, Ent, R, Fanelli, C, Franklin, G, Fuchey, E, Gal, C, Gaskell, D, Gautam, T, Glamazdin, O, Gnanvo, K, Gray, VM, Gu, C, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, CE, Ibrahim, H, Jen, C-M, Jin, K, Jones, M, Kabir, A, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, WB, Liu, J, Liu, H, Liyanage, A, Magee, J, Malace, S, Mammei, J, Markowitz, P, McClellan, E, Mazouz, M, and Meddi, F

Subjects
Jefferson Lab Hall A Collaboration, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.

Published
2022

15. Spectroscopic study of a possible Λnn resonance and a pair of ΣNN states using the (e,e′K+) reaction with a tritium target

Author

Pandey, B, Tang, L, Gogami, T, Suzuki, KN, Itabashi, K, Nagao, S, Okuyama, K, Nakamura, SN, Abrams, D, Afnan, IR, Akiyama, T, Androic, D, Aniol, K, Averett, T, Gayoso, C Ayerbe, Bane, J, Barcus, S, Barrow, J, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Camsonne, A, Castellanos, J, Chen, J-P, Chen, J, Covrig, S, Chrisman, D, Cruz-Torres, R, Das, R, Fuchey, E, Gal, C, Gibson, BF, Gnanvo, K, Garibaldi, F, Gautam, T, Gomez, J, Gueye, P, Hague, TJ, Hansen, O, Henry, W, Hauenstein, F, Higinbotham, DW, Hyde, C, Kaneta, M, Keppel, C, Kutz, T, Lashley-Colthirst, N, Li, S, Liu, H, Mammei, J, Markowitz, P, McClellan, RE, Meddi, F, Meekins, D, Michaels, R, Mihovilovič, M, Moyer, A, Nguyen, D, Nycz, M, Owen, V, Palatchi, C, Park, S, Petkovic, T, Premathilake, S, Reimer, PE, Reinhold, J, Riordan, S, Rodriguez, V, Samanta, C, Santiesteban, SN, Sawatzky, B, Širca, S, Slifer, K, Su, T, Tian, Y, Toyama, Y, Uehara, K, Urciuoli, GM, Votaw, D, Williamson, J, Wojtsekhowski, B, Wood, S, Yale, B, Ye, Z, Zhang, J, and Zheng, X

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract

A mass spectroscopy experiment with a pair of nearly identical high-resolution spectrometers and a tritium target was performed in Hall A at Jefferson Lab. Utilizing the (e,e′K+) reaction, enhancements, which may correspond to a possible Λnn resonance and a pair of ςNN states, were observed with an energy resolution of about 1.21 MeV (σ), although greater statistics are needed to make definitive identifications. An experimentally measured Λnn state may provide a unique constraint in determining the Λn interaction, for which no scattering data exist. In addition, although bound A=3 and 4 ς hypernuclei have been predicted, only an A=4 ς hypernucleus (Heς4) was found, utilizing the (K-,π-) reaction on a He4 target. The possible bound ςNN state is likely a ς0nn state, although this has to be confirmed by future experiments.

Published
2022

16. Measurement of the Nucleon F2n/F2p Structure Function Ratio by the Jefferson Lab MARATHON Tritium/Helium-3 Deep Inelastic Scattering Experiment

Author

Abrams, D, Albataineh, H, Aljawrneh, BS, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Butler, J, Camsonne, A, Carmignotto, M, Castellanos, J, Chen, J-P, Cohen, EO, Covrig, S, Craycraft, K, Cruz-Torres, R, Dongwi, B, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, J-O, Hattawy, M, Hauenstein, F, Higinbotham, DW, Holt, RJ, Hughes, EW, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Karki, A, Karki, B, Katramatou, AT, Keith, C, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, Kievsky, A, King, D, King, PM, Korover, I, Kulagin, SA, Kumar, KS, Kutz, T, Lashley-Colthirst, N, Li, S, Li, W, Liu, H, Liuti, S, Liyanage, N, Markowitz, P, McClellan, RE, Meekins, D, Beck, S Mey-Tal, Meziani, Z-E, Michaels, R, Mihovilovic, M, Nelyubin, V, Nguyen, D, Nuruzzaman, Nycz, M, Obrecht, R, Olson, M, Owen, VF, Pace, E, Pandey, B, Pandey, V, Paolone, M, Papadopoulou, A, Park, S, Paul, S, Petratos, GG, Petti, R, Piasetzky, E, and Pomatsalyuk, R

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Jefferson Lab Hall A Tritium Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The ratio of the nucleon F_{2} structure functions, F_{2}^{n}/F_{2}^{p}, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ^{3}H and ^{3}He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken scaling variable range 0.19

Published
2022

17. 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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18. Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

Author

Christy, ME, Gautam, T, Ou, L, Schmookler, B, Wang, Y, Adikaram, D, Ahmed, Z, Albataineh, H, Ali, SF, Aljawrneh, B, Allada, K, Allison, SL, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Bhatt, H, Bhetuwal, D, Biswas, D, Brash, E, Bulumulla, D, Camacho, CM, Campbell, J, Camsonne, A, Carmignotto, M, Castellanos, J, Chen, C, Chen, J-P, Chetry, T, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Dusa, S Covrig, Crowe, B, Danagoulian, S, Danley, T, Deconinck, W, Defurne, M, Desnault, C, Di, D, Dlamini, M, Duer, M, Duran, B, Ent, R, Fanelli, C, Fuchey, E, Gal, C, Gaskell, D, Georges, F, Gilad, S, Glamazdin, O, Gnanvo, K, Gramolin, AV, Gray, VM, Gu, C, Habarakada, A, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Hernandez, AV, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, C, Ibrahim, H, Israel, N, Jen, C-M, Jin, K, Jones, M, Kabir, A, Karki, B, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, W, Liu, H, Liu, J, Liyanage, AH, Mack, D, and Magee, J

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75  (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8  (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.

Published
2022

19. The cross-section measurement for the 3H(e, e′K+)nnΛ reaction

Author

Suzuki, KN, Gogami, T, Pandey, B, Itabashi, K, Nagao, S, Okuyama, K, Nakamura, SN, Tang, L, Abrams, D, Akiyama, T, Androic, D, Aniol, K, Gayoso, C Ayerbe, Bane, J, Barcus, S, Barrow, J, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Camsonne, A, Castellanos, J, Chen, J-P, Chen, J, Covrig, S, Chrisman, D, Cruz-Torres, R, Das, R, Fuchey, E, Gnanvo, K, Garibaldi, F, Gautam, T, Gomez, J, Gueye, P, Hague, TJ, Hansen, O, Henry, W, Hauenstein, F, Higinbotham, DW, Hyde, CE, Kaneta, M, Keppel, C, Kutz, T, Lashley-Colthirst, N, Li, S, Liu, H, Mammei, J, Markowitz, P, McClellan, RE, Meddi, F, Meekins, D, Michaels, R, Mihovilovič, M, Moyer, A, Nguyen, D, Nycz, M, Owen, V, Palatchi, C, Park, S, Petkovic, T, Premathilake, S, Reimer, PE, Reinhold, J, Riordan, S, Rodriguez, V, Samanta, C, Santiesteban, SN, Sawatzky, B, Širca, S, Slifer, K, Su, T, Tian, Y, Toyama, Y, Uehara, K, Urciuoli, GM, Votaw, D, Williamson, J, Wojtsekhowski, B, Wood, SA, Yale, B, Ye, Z, Zhang, J, and Zheng, X

Subjects
Mathematical Sciences, Physical Sciences
Abstract

The small binding energy of the hypertriton leads to predictions of the non-existence of bound hypernuclei for isotriplet three-body systems such as nnΛ. However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound nnΛ state. The nnΛ state was sought by missing-mass spectroscopy via the (e, e′K+) reaction at Jefferson Lab's experimental Hall A. The present experiment has higher sensitivity to the nnΛ-state investigation in terms of better precision by a factor of about three. The analysis shown in this article focuses on the derivation of the reaction cross-section for the 3H(γ∗, K+)X reaction. Events that were detected in an acceptance, where a Monte Carlo simulation could reproduce the data well (δ p/p| < 4), were analyzed to minimize the systematic uncertainty. No significant structures were observed with the acceptance cuts, and the upper limits of the production cross-section of the nnΛ state were obtained to be 21 and 31 nb sr-1 at the $90\%$ confidence level when theoretical predictions of (-BΛ, Γ) = (0.25, 0.8) MeV and (0.55, 4.7) MeV, respectively, were assumed. The cross-section result provides valuable information for examining the existence of nnΛ.

Published
2022

20. Measurement of the Nucleon $F^n_2/F^p_2$ Structure Function Ratio by the Jefferson Lab MARATHON Tritium/Helium-3 Deep Inelastic Scattering Experiment

Author

MARATHON Collaboration, Abrams, D., Albataineh, H., Aljawrneh, B. S., Alsalmi, S., Aniol, K., Armstrong, W., Arrington, J., Atac, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Beck, A., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Blyth, D., Boeglin, W., Bulumulla, D., Butler, J., Camsonne, A., Carmignotto, M., Castellanos, J., Chen, J. -P., Cohen, E. O., Covrig, S., Craycraft, K., Cruz-Torres, R., Dongwi, B., Duran, B., Dutta, D., Fuchey, E., Gal, C., Gautam, T. N., Gilad, S., Gnanvo, K., Gogami, T., Gomez, J., Gu, C., Habarakada, A., Hague, T., Hansen, J. -O., Hattawy, M., Hauenstein, F., Higinbotham, D. W., Holt, R. J., Hughes, E. W., Hyde, C., Ibrahim, H., Jian, S., Joosten, S., Karki, A., Karki, B., Katramatou, A. T., Keith, C., Keppel, C., Khachatryan, M., Khachatryan, V., Khanal, A., Kievsky, A., King, D., King, P. M., Korover, I., Kulagin, S. A., Kumar, K. S., Kutz, T., Lashley-Colthirst, N., Li, S., Li, W., Liu, H., Liuti, S., Liyanage, N., Markowitz, P., McClellan, R. E., Meekins, D., Beck, S. Mey-Tal, Meziani, Z. -E., Michaels, R., Mihovilovic, M., Nelyubin, V., Nguyen, D., Nuruzzaman, Nycz, M., Obrecht, R., Olson, M., Owen, V. F., Pace, E., Pandey, B., Pandey, V., Paolone, M., Papadopoulou, A., Park, S., Paul, S., Petratos, G. G., Petti, R., Piasetzky, E., Pomatsalyuk, R., Premathilake, S., Puckett, A. J. R., Punjabi, V., Ransome, R. D., Rashad, M. N. H., Reimer, P. E., Riordan, S., Roche, J., Salme, G., Santiesteban, N., Sawatzky, B., Scopetta, S., Schmidt, A., Schmookler, B., Segal, J., Segarra, E. P., Shahinyan, A., Sirca, S., Sparveris, N., Su, T., Suleiman, R., Szumila-Vance, H., Tadepalli, A. S., Tang, L., Tireman, W., Tortorici, F., Urciuoli, G. M., Wojtsekhowski, B., Wood, S., Ye, Z. H., Ye, Z. Y., and Zhang, J.

Subjects
High Energy Physics - Experiment
Abstract

The ratio of the nucleon $F_2$ structure functions, $F_2^n/F_2^p$, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from $^3$H and $^3$He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab and used two high resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken scaling variable range $0.19 < x < 0.83$, represent a significant improvement compared to previous SLAC and Jefferson Lab measurements for the ratio. They are compared to recent theoretical calculations and empirical determinations of the $F_2^n/F_2^p$ ratio.

Published
2021

21. Measurement of the generalized spin polarizabilities of the neutron in the low $Q^2$ region

Author

Sulkosky, V., Peng, C., Chen, J. -P., Deur, A., Abrahamyan, S., Aniol, K. A., Armstrong, D. S., Averett, T., Bailey, S. L., Beck, A., Bertin, P., Butaru, F., Boeglin, W., Camsonne, A., Cates, G. D., Chang, C. C., Choi, Seonho, Chudakov, E., Coman, L., Cornejo, J. C, Craver, B., Cusanno, F., De Leo, R., de Jager, C. W., Denton, J. D., Dhamija, S., Feuerbach, R., Finn, J. M., Frullani, S., Fuoti, K., Gao, H., Garibaldi, F., Gayou, O., Gilman, R., Glamazdin, A., Glashausser, C., Gomez, J., Hansen, J. -O., Hayes, D., Hersman, B., Higinbotham, D. W., Holmstrom, T., Humensky, T. B., Hyde, C. E., Ibrahim, H., Iodice, M., Jiang, X., Kaufman, L. J., Kelleher, A., Keister, K. E., Kim, W., Kolarkar, A., Kolb, N., Korsch, W., Kramer, K., Kumbartzki, G., Lagamba, L., Laine, V., Laveissiere, G., Lerose, J. J., Lhuillier, D., Lindgren, R., Liyanage, N., Lu, H. -J., Ma, B., Margaziotis, D. J., Markowitz, P., McCormick, K., Meziane, M., Meziani, Z. -E., Michaels, R., Moffit, B., Monaghan, P., Nanda, S., Niedziela, J., Niskin, M., Pandolfi, R., Paschke, K. D., Potokar, M., Puckett, A., Punjabi, V. A., Qiang, Y., Ransome, R., Reitz, B., Roche, R., Saha, A., Shabetai, A., Sirca, S., Singh, J. T., Slifer, K., Snyder, R., Solvignon, P., Stringer, R., Subedi, R., Tobias, W. A., Ton, N., Ulmer, P. E., Urciuoli, G. M., Vacheret, A., Voutier, E., Wang, K., Wan, L., Wojtsekhowski, B., Woo, S., Yao, H., Yuan, J., Zhan, X., Zheng, X., and Zhu, L.

Subjects
Nuclear Experiment
Abstract

Understanding the nucleon spin structure in the regime where the strong interaction becomes truly strong poses a challenge to both experiment and theory. At energy scales below the nucleon mass of about 1 GeV, the intense interaction among the quarks and gluons inside the nucleon makes them highly correlated. Their coherent behaviour causes the emergence of effective degrees of freedom, requiring the application of non-perturbative techniques, such as chiral effective field theory. Here, we present measurements of the neutron's generalized spin-polarizabilities that quantify the neutron's spin precession under electromagnetic fields at very low energy-momentum transfer squared down to 0.035 GeV$^2$. In this regime, chiral effective field theory calculations are expected to be applicable. Our data, however, show a strong discrepancy with these predictions, presenting a challenge to the current description of the neutron's spin properties., Comment: V1: initial version submitted to Nature Physics. V2: Published version. 16 pages, 7 figures. Additional material: 4 data tables (18 pages) V3: Typo corrected in author list. Paper content unchanged

Published
2021
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22. Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

Author

Christy, M. E., Gautam, T., Ou, L., Schmookler, B., Wang, Y., Adikaram, D., Ahmed, Z., Albataineh, H., Ali, S. F., Aljawrneh, B., Allada, K., Allison, S. L., Alsalmi, S., Androic, D., Aniol, K., Annand, J., Arrington, J., Atac, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Bartlett, K., Bellini, V., Beminiwattha, R., Bericic, J., Bhatt, H., Bhetuwal, D., Biswas, D., Brash, E., Bulumulla, D., Camacho, C. M., Campbell, J., Camsonne, A., Carmignotto, M., Castellanos, J., Chen, C., Chen, J-P., Chetry, T., Cisbani, E., Clary, B., Cohen, E., Compton, N., Cornejo, J. C., Dusa, S. Covrig, Crowe, B., Danagoulian, S., Danley, T., Deconinck, W., Defurne, M., Desnault, C., Di, D., Dlamini, M., Duer, M., Duran, B., Ent, R., Fanelli, C., Fuchey, E., Gal, C., Gaskell, D., Georges, F., Gilad, S., Glamazdin, O., Gnanvo, K., Gramolin, A. V., Gray, V. M., Gu, C., Habarakada, A., Hague, T., Hamad, G., Hamilton, D., Hamilton, K., Hansen, O., Hauenstein, F., Hernandez, A. V., Henry, W., Higinbotham, D. W., Holmstrom, T., Horn, T., Huang, Y., Huber, G. M., Hyde, C., Ibrahim, H., Israel, N., Jen, C-M., Jin, K., Jones, M., Kabir, A., Karki, B., Keppel, C., Khachatryan, V., King, P. M., Li, S., Li, W., Liu, H., Liu, J., Liyanage, A. H., Mack, D., Magee, J., Malace, S., Mammei, J., Markowitz, P., Mayilyan, S., McClellan, E., Meddi, F., Meekins, D., Mesick, K., Michaels, R., Mkrtchyan, A., Moffit, B., Montgomery, R., Myers, L. S., Nadel-Turonski, P., Nazeer, S. J., Nelyubin, V., Nguyen, D., Nuruzzaman, N., Nycz, M., Obrecht, R. F., Ohanyan, K., Palatchi, C., Pandey, B., Park, K., Park, S., Peng, C., Persio, F. D., Pomatsalyuk, R., Pooser, E., Puckett, A. J. R., Punjabi, V., Quinn, B., Rahman, S., Rashad, M. N. H., Riordan, S., Roche, J., Sapkota, I., Sarty, A., Sawatzky, B., Saylor, N. H., Shabestari, M. H., Shahinyan, A., Sirca, S., Smith, G. R., Sooriyaarachchilage, S., Sparveris, N., Spies, R., Stefanko, A., Su, T., Subedi, A., Sulkosky, V., Sun, A., Tan, Y., Thorne, L., Ton, N., Tortorici, F., Trotta, R., Uniyal, R., Urciuoli, G. M., Voutier, E., Waidyawansa, B., Wojtsekhowski, B., Wood, S., Yan, X., Ye, L., Ye, Z. H., Yero, C., Zhang, J., Zhao, Y. X., and Zhu, P.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q$^2$) up to 15.75~\gevsq. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q$^2$ and double the range over which a longitudinal/transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q$^2$ and attributed to hard two-photon exchange (TPE) effects, extending to 8~(GeV/c)$^2$ the range of Q$^2$ for which a discrepancy is established at $>$95\% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q$^2$., Comment: 7 pages, 2 figures

Published
2021
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23. Accurate Determination of the Neutron Skin Thickness of $^{208}$Pb through Parity-Violation in Electron Scattering

Author

Adhikari, D., Albataineh, H., Androic, D., Aniol, K., Armstrong, D. S., Averett, T., Barcus, S., Bellini, V., Beminiwattha, R. S., Benesch, J. F., Bhatt, H., Pathak, D. Bhatta, Bhetuwal, D., Blaikie, B., Campagna, Q., Camsonne, A., Cates, G. D., Chen, Y., Clarke, C., Cornejo, J. C., Dusa, S. Covrig, Datta, P., Deshpande, A., Dutta, D., Feldman, C., Fuchey, E., Gal, C., Gaskell, D., Gautam, T., Gayoso, C. Ayerbe, Gericke, M., Ghosh, C., Halilovic, I., Hansen, J. -O., Hauenstein, F., Henry, W., Horowitz, C. J., Jantzi, C., Jian, S., Johnston, S., Jones, D. C., Karki, B., Katugampola, S., Keppel, C., King, P. M., King, D. E., Knauss, M., Kumar, K. S., Kutz, T., Lashley-Colthirst, N., Leverick, G., Liu, H., Liyange, N., Malace, S., Mammei, R., Mammei, J., McCaughan, M., McNulty, D., Meekins, D., Metts, C., Michaels, R., Mondal, M. M., Napolitano, J., Narayan, A., Nikolaev, D., Rashad, M. N. H., Owen, V., Palatchi, C., Pan, 14 J., Pandey, B., Park, S., Paschke, K. D., Petrusky, M., Pitt, M. L., Premathilake, S., Puckett, A. J. R., Quinn, B., Radloff, R., Rahman, S., Rathnayake, A., Reed, B. T., Reimer, P. E., Richards, R., Riordan, S., Roblin, Y., Seeds, S., Shahinyan, A., Souder, P., Tang, L., Thiel, 16 M., Tian, Y., Urciuoli, G. M., Wertz, E. W., Wojtsekhowski, B., Yale, B., Ye, T., Yoon, A., Zec, A., Zhang, W., Zhang, J., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

We report a precision measurement of the parity-violating asymmetry $A_{PV}$ in the elastic scattering of longitudinally polarized electrons from $^{208}$Pb. We measure $A_{PV}=550\pm 16 {\rm (stat)}\pm 8\ {\rm (syst)}$ parts per billion, leading to an extraction of the neutral weak form factor $F_W(Q^2 = 0.00616\ {\rm GeV}^2) = 0.368 \pm 0.013$. Combined with our previous measurement, the extracted neutron skin thickness is $R_n-R_p=0.283 \pm 0.071$~fm. The result also yields the first significant direct measurement of the interior weak density of $^{208}$Pb: $\rho^0_W = -0.0796\pm0.0036\ {\rm (exp.)}\pm0.0013\ {\rm (theo.)}\ {\rm fm}^{-3}$ leading to the interior baryon density $\rho^0_b = 0.1480\pm0.0036\ {\rm (exp.)}\pm0.0013\ {\rm (theo.)}\ {\rm fm}^{-3}$. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars.

Published
2021
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24. Deep Exclusive Electroproduction of π0 at High Q2 in the Quark Valence Regime

Author

Dlamini, M, Karki, B, Ali, SF, Lin, P-J, Georges, F, Ko, H-S, Israel, N, Rashad, MNH, Stefanko, A, Adikaram, D, Ahmed, Z, Albataineh, H, Aljawrneh, B, Allada, K, Allison, S, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Atac, H, Averett, T, Ayerbe Gayoso, C, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Biswas, D, Brash, E, Bulumulla, D, Campbell, J, Camsonne, A, Carmignotto, M, Castellano, J, Chen, C, Chen, J-P, Chetry, T, Christy, ME, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Covrig Dusa, S, Crowe, B, Danagoulian, S, Danley, T, De Persio, F, Deconinck, W, Defurne, M, Desnault, C, Di, D, Duer, M, Duran, B, Ent, R, Fanelli, C, Franklin, G, Fuchey, E, Gal, C, Gaskell, D, Gautam, T, Glamazdin, O, Gnanvo, K, Gray, VM, Gu, C, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, C, Ibrahim, H, Jen, C-M, Jin, K, Jones, M, Kabir, A, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, W, Liu, J, Liu, H, Liyanage, A, Magee, J, Malace, S, Mammei, J, Markowitz, P, McClellan, E, Meddi, F, and Meekins, D

Subjects
Jefferson Lab Hall A Collaboration, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of x_{B} (0.36, 0.48, and 0.60) and Q^{2} (3.1 to 8.4  GeV^{2}) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσ_{T}/dt+εdσ_{L}/dt, dσ_{TT}/dt, dσ_{LT}/dt, and dσ_{LT^{'}}/dt are extracted as a function of the proton momentum transfer t-t_{min}. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

Published
2021

25. Deep exclusive electroproduction of $\pi^0$ at high $Q^2$ in the quark valence regime

Author

The Jefferson Lab Hall A Collaboration, Dlamini, M., Karki, B., Ali, S. F., Lin, P-J., Georges, F., Ko, H-S, Israel, N., Rashad, M. N. H., Stefanko, A., Adikaram, D., Ahmed, Z., Albataineh, H., Aljawrneh, B., Allada, K., Allison, S., Alsalmi, S., Androic, D., Aniol, K., Annand, J., Atac, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Bartlett, K., Bellini, V., Beminiwattha, R., Bericic, J., Biswas, D., Brash, E., Bulumulla, D., Campbell, J., Camsonne, A., Carmignotto, M., Castellano, J., Chen, C., Chen, J-P., Chetry, T., Christy, M. E., Cisbani, E., Clary, B., Cohen, E., Compton, N., Cornejo, J. C., Dusa, S. Covrig, Crowe, B., Danagoulian, S., Danley, T., De Persio, F., Deconinck, W., Defurne, M., Desnault, C., Di, D., Duer, M., Duran, B., Ent, R., Fanelli, C., Franklin, G., Fuchey, E., Gal, C., Gaskell, D., Gautam, T., Glamazdin, O., Gnanvo, K., Gray, V. M., Gu, C., Hague, T., Hamad, G., Hamilton, D., Hamilton, K., Hansen, O., Hauenstein, F., Henry, W., Higinbotham, D. W., Holmstrom, T., Horn, T., Huang, Y., Huber, G. M., Hyde, C., Ibrahim, H., Jen, C-M., Jin, K., Jones, M., Kabir, A., Keppel, C., Khachatryan, V., King, P. M., Li, S., Li, W., Liu, J., Liu, H., Liyanage, A., Magee, J., Malace, S., Mammei, J., Markowitz, P., McClellan, E., Meddi, F., Meekins, D., Mesik, K., Michaels, R., Mkrtchyan, A., Montgomery, R., Camacho, C. Munoz, Myers, L. S., Nadel-Turonski, P., Nazeer, S. J., Nelyubin, V., Nguyen, D., Nuruzzaman, N., Nycz, M., Obretch, O. F., Ou, L., Palatchi, C., Pandey, B., Park, S., Park, K., Peng, C., Pomatsalyuk, R., Pooser, E., Puckett, A. J. R., Punjabi, V., Quinn, B., Rahman, S., Reimer, P. E., Roche, J., Sapkota, I., Sarty, A., Sawatzky, B., Saylor, N. H., Schmookler, B., Shabestari, M. H., Shahinyan, A., Sirca, S., Smith, G. R., Sooriyaarachchilage, S., Sparveris, N., Spies, R., Su, T., Subedi, A., Sulkosky, V., Sun, A., Thorne, L., Tian, Y., Ton, N., Tortorici, F., Trotta, R., Urciuoli, G. M., Voutier, E., Waidyawansa, B., Wang, Y., Wojtsekhowski, B., Wood, S., Yan, X., Ye, L., Ye, Z., Yero, C., Zhang, J., Zhao, Y., and Zhu, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of $x_B$ (0.36, 0.48 and 0.60) and $Q^2$ (3.1 to 8.4 GeV$^2$) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions $d\sigma_L/dt+\epsilon d\sigma_T/dt$, $d\sigma_{TT}/dt$, $d\sigma_{LT}/dt$ and $d\sigma_{LT'}/dt$ are extracted as a function of the proton momentum transfer $t-t_{min}$. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross-section throughout this kinematic range. The data are well described by calculations based on transversity Generalized Parton Distributions coupled to a helicity flip Distribution Amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

Published
2020
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26. Backward-angle Exclusive pi0 Production above the Resonance Region

Author

Li, W. B., Huber, G. M., Stevens, J. R., Semenov-Tian-Shansky, K., Szymanowski, L., Pire, B., Amaryan, M., Androic, D., Aniol, K., Armstrong, D., Averett, T., Gayoso, C. Ayerbe, Boeglin, W., Boer, M., Camsonne, A., Chen, J., Dusa, S. Covrig, Deconinck, W., Defurne, M., Delcarro, F., Diefenthaler, M., Diehl, S., Elaasar, M., Fanelli, C., Fegan, S., Fuchey, E., Gaskell, D., Hansen, O., Hauenstein, F., Higinbotham, D., Blin, A. Hiller, Hurley, A., Hyde, C., Joo, K., Junaid, M., Kalantarians, N., Kay, S., Khachatryan, M., King, P., Kumar, V., Lersch, D., Lorenti, L., Markowitz, P., McCaughan, M., Mkrtchyan, A., Mkrtchyan, H., Niculescu, G., Niculescu, I., Papandreou, Z., Paremuzyan, R., Park, K., Paudyal, D., Roche, J., Rodas, A., Sawatzky, B., Schertz, A., Smith, G., Strakovsky, I., Tadevosyan, V., Usman, A., Voskanyan, H., and Yero, C.

Subjects
Nuclear Experiment
Abstract

The proposed measurement is a dedicated study of the exclusive electroproduction process,1H(e,e'p)pi0, in the backward-angle regime (u-channel process) above the resonance region. The produced pi0 is emitted 180 degrees opposite to the virtual-photon momentum. This study also aims to apply the well-known Rosenbluth separation technique that provides the model-independent differential cross-sections at the never explored u-channel kinematics region. Currently, the "soft-hard transition" in u-channel meson production remains an interesting and unexplored subject. The available theoretical frameworks offer competing interpretations for the observed backward-angle cross section peaks. In a "soft" hadronic Regge exchange description, the backward meson production comes from the interference between nucleon exchange and the meson produced via re-scattering within the nucleon. Whereas in the "hard" GPD-like backward collinear factorization regime, the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes (TDAs), otherwise known as super skewed parton distributions (SuperSPDs). Both TDAs and SPDs are universal non-perturbative objects of nucleon structure accessible only through backward-angle kinematics. The separated cross sections:sigma_T,sigma_L and T/L ratio at Q2=2-6 GeV2, provide a direct test of two predictions from the TDA model. The magnitude and u-dependence of the separated cross sections also provide a direct connection to the re-scattering Regge picture. The extracted interaction radius (from u-dependence) at different Q2 can be used to study the soft-hard transition in the u-channel kinematics. The acquisition of these data will be an important step forward in validating the existence of a backward factorization scheme of the nucleon structure function and establishing its applicable kinematic range.

Published
2020

27. 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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28. Probing few-body nuclear dynamics via 3H and 3He (e,e'p)pn cross-section measurements

Author

Cruz-Torres, R., Nguyen, D., Hauenstein, F., Schmidt, A., Li, S., Abrams, D., Albataineh, H., Alsalmi, S., Androic, D., Aniol, K., Armstrong, W., Arrington, J., Atac, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Beck, A., Bellini, V., Benmokhtar, F., Bhatt, H., Bhetuwal, D., Biswas, D., Blyth, D., Boeglin, W., Bulumulla, D., Camsonne, A., Castellanos, J., Chen, J-P., Cohen, E. O., Covrig, S., Craycraft, K., Dongwi, B., Duer, M., Duran, B., Dutta, D., Fuchey, E., Gal, C., Gautam, T. N., Gilad, S., Gnanvo, K., Gogami, T., Golak, J., Gomez, J., Gu, C., Hague, A. Habarakada T., Hansen, O., Hattawy, M., Hen, O., Higinbotham, D. W., Hughes, E., Hyde, C., Ibrahim, H., Jian, S., Joosten, S., Kamada, H., Karki, A., Karki, B., Katramatou, A. T., Keppel, C., Khachatryan, M., Khachatryan, V., Khanal, A., King, D., King, P., Korover, I., Kutz, T., Lashley-Colthirst, N., Laskaris, G., Li, W., Liu, H., Liyanage, N., Markowitz, P., McClellan, R. E., Meekins, D., Meziani, S. Mey-Tal Beck Z-E., Michaels, R., Mihovilovic, M., Nelyubin, V., Nuruzzaman, N., Nycz, M., Obrecht, R., Olson, M., Ou, L., Owen, V., Pandey, B., Pandey, V., Papadopoulou, A., Park, S., Patsyuk, M., Paul, S., Petratos, G. G., Piasetzky, E., Pomatsalyuk, R., Premathilake, S., Puckett, A. J. R., Punjabi, V., Ransome, R., Rashad, M. N. H., Reimer, P. E., Riordan, S., Roche, J., Sargsian, M., Santiesteban, N., Sawatzky, B., Segarra, E. P., Schmookler, B., Shahinyan, A., Sirca, S., Skibinski, R., Sparveris, N., Su, T., Suleiman, R., Szumila-Vance, H., Tadepalli, A. S., Tang, L., Tireman, W., Topolnicki, K., Tortorici, F., Urciuoli, G., Weinstein, L. B., Witala, H., Wojtsekhowski, B., Wood, S., Ye, Z. H., Ye, Z. Y., and Zhang, J.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We report the first measurement of the \eep three-body breakup reaction cross sections in helium-3 ($^3$He) and tritium ($^3$H) at large momentum transfer ($\langle Q^2 \rangle \approx 1.9$ (GeV/c)$^2$) and $x_B>1$ kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta $40 \le p_{miss} \le 500$ MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab-initio calculations. Overall good agreement, within $\pm20\%$, is observed between data and calculations for the full $p_{miss}$ range for $^3$H and for $100 \le p_{miss} \le 350$ MeV/c for $^3$He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at $p_{miss} > 250$ MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of $^3$He plus $^3$H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire $p_{miss}$ range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of $500$ MeV/c., Comment: Accepted for publication in PRL. 8 pages, 3 figures, and online supplementary materials

Published
2020
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29. Measurement of the Nucleon $F^n_2/F^p_2$ Structure Function Ratio by the Jefferson Lab MARATHON Tritium/Helium-3 Deep Inelastic Scattering Experiment

Author

Collaboration, MARATHON, Abrams, D, Albataineh, H, Aljawrneh, BS, Alsalmi, S, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Butler, J, Camsonne, A, Carmignotto, M, Castellanos, J, Chen, J-P, Cohen, EO, Covrig, S, Craycraft, K, Cruz-Torres, R, Dongwi, B, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, J-O, Hattawy, M, Hauenstein, F, Higinbotham, DW, Holt, RJ, Hughes, EW, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Karki, A, Karki, B, Katramatou, AT, Keith, C, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, Kievsky, A, King, D, King, PM, Korover, I, Kulagin, SA, Kumar, KS, Kutz, T, Lashley-Colthirst, N, Li, S, Li, W, Liu, H, Liuti, S, Liyanage, N, Markowitz, P, McClellan, RE, Meekins, D, Beck, S Mey-Tal, Meziani, Z-E, Michaels, R, Mihovilovic, M, Nelyubin, V, Nguyen, D, Nuruzzaman, Nycz, M, Obrecht, R, Olson, M, Owen, VF, Pace, E, Pandey, B, Pandey, V, Paolone, M, Papadopoulou, A, Park, S, Paul, S, Petratos, GG, Petti, R, Piasetzky, E, and Pomatsalyuk, R

Subjects
hep-ex
Abstract

The ratio of the nucleon $F_2$ structure functions, $F_2^n/F_2^p$, isdetermined by the MARATHON experiment from measurements of deep inelasticscattering of electrons from $^3$H and $^3$He nuclei. The experiment wasperformed in the Hall A Facility of Jefferson Lab and used two high resolutionspectrometers for electron detection, and a cryogenic target system whichincluded a low-activity tritium cell. The data analysis used a novel techniqueexploiting the mirror symmetry of the two nuclei, which essentially eliminatesmany theoretical uncertainties in the extraction of the ratio. The results,which cover the Bjorken scaling variable range $0.19 < x < 0.83$, represent asignificant improvement compared to previous SLAC and Jefferson Labmeasurements for the ratio. They are compared to recent theoreticalcalculations and empirical determinations of the $F_2^n/F_2^p$ ratio.

Published
2021

30. Exclusive $\pi^+$ electroproduction off the proton from low to high -t

Author

Basnet, S., Huber, G. M., Li, W. B., Blok, H. P., Gaskell, D., Horn, T., Aniol, K., Arrington, J., Beise, E. J., Boeglin, W., Brash, E. J., Breuer, H., Chang, C. C., Christy, M. E., Ent, R., Gibson, E., Holt, R. J., Jin, S., Jones, M. K., Keppel, C. E., Kim, W., King, P. M., Kovaltchouk, V., Liu, J., Lolos, G. J., Mack, D. J., Margaziotis, D. J., Markowitz, P., Matsumura, A., Meekins, D., Miyoshi, T., Mkrtchyan, H., Niculescu, I., Okayasu, Y., Pentchev, L., Perdrisat, C., Potterveld, D., Punjabi, V., Reimer, P., Reinhold, J., Roche, J., Sarty, A., Smith, G. R., Tadevosyan, V., Tang, L. G., Tvaskis, V., Volmer, J., Vulcan, W., Warren, G., Wood, S. A., Xu, C., and Zheng, X.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. Purpose: To study the transition between non-perturbative and perturbative Quantum Chromodyanmics as the square of four momentum transfer to the struck proton, -t, is increased. Method: Cross sections for the $^1$H(e,e'$\pi^+$)n reaction were measured over the -t range of 0.272 to 2.127 GeV$^2$ with limited azimuthal coverage at fixed beam energy of 4.709 GeV, Q$^2$ of 2.4 GeV$^2$ and W of 2.0 GeV at the Thomas Jefferson National Accelerator Facility (JLab) Hall C. Results: The -t dependence of the measured $\pi^+$ electroproduction cross section generally agrees with prior data from JLab Halls B and C. The data are consistent with a Regge amplitude based theoretical model, but show poor agreement with a Generalized Parton Distribution (GPD) based model. Conclusion: The agreement of cross sections with prior data implies small contribution from the interference terms, and the confirmation of the change in t-slopes between the low and high -t regions previously observed in photoproduction indicates the changing nature of the electroproduction reaction in our kinematic regime., Comment: 9 pages, 5 figures Physical Review C, in press

Published
2019
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31. Unique Access to u-Channel Physics: Exclusive Backward-Angle Omega Meson Electroproduction

Author

Li, W. B., Huber, G. M., Blok, H. P., Gaskell, D., Horn, T., Semenov-Tian-Shansky, K., Pire, B., Szymanowski, L., Laget, J. -M., Aniol, K., Arrington, J., Beise, E. J., Boeglin, W., Brash, E. J., Breuer, H., Chang, C. C., Christy, M. E., Ent, R., Gibson, E. F., Holt, R. J., Jin, S., Jones, M. K., Keppel, C. E., Kim, W., King, P. M., Kovaltchouk, V., Liu, J., Lolos, G. J., Mack, D. J., Margaziotis, D. J., Markowitz, P., Matsumura, A., Meekins, D., Miyoshi, T., Mkrtchyan, H., Niculescu, I., Okayasu, Y., Pentchev, L., Perdrisat, C., Potterveld, D., Punjabi, V., Reimer, P. E., Reinhold, J., Roche, J., Roos, P. G., Sarty, A., Smith, Tadevosyan, V., Tang, L. G., Tvaskis, V., Volmer, J., Vulcan, W., Warren, G., Wood, S. A., Xu, C., and Zheng, X.

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

Backward-angle meson electroproduction above the resonance region, which was previously ignored, is anticipated to offer unique access to the three quark plus sea component of the nucleon wave function. In this letter, we present the first complete separation of the four electromagnetic structure functions above the resonance region in exclusive omega electroproduction off the proton, e + p -> e' + p + omega, at central Q^2 values of 1.60, 2.45 GeV^2 , at W = 2.21 GeV. The results of our pioneering -u ~ -u min study demonstrate the existence of a unanticipated backward-angle cross section peak and the feasibility of full L/T/LT/TT separations in this never explored kinematic territory. At Q^2 =2.45 GeV^2 , the observed dominance of sigma_T over sigma_L, is qualitatively consistent with the collinear QCD description in the near-backward regime, in which the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes (TDAs): universal non-perturbative objects only accessible through backward angle kinematics.

Published
2019

32. Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

Author

Christy, ME, Gautam, T, Ou, L, Schmookler, B, Wang, Y, Adikaram, D, Ahmed, Z, Albataineh, H, Ali, SF, Aljawrneh, B, Allada, K, Allison, SL, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Bhatt, H, Bhetuwal, D, Biswas, D, Brash, E, Bulumulla, D, Camacho, CM, Campbell, J, Camsonne, A, Carmignotto, M, Castellanos, J, Chen, C, Chen, J-P, Chetry, T, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Dusa, S Covrig, Crowe, B, Danagoulian, S, Danley, T, Deconinck, W, Defurne, M, Desnault, C, Di, D, Dlamini, M, Duer, M, Duran, B, Ent, R, Fanelli, C, Fuchey, E, Gal, C, Gaskell, D, Georges, F, Gilad, S, Glamazdin, O, Gnanvo, K, Gramolin, AV, Gray, VM, Gu, C, Habarakada, A, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Hernandez, AV, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, C, Ibrahim, H, Israel, N, Jen, C-M, Jin, K, Jones, M, Kabir, A, Karki, B, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, W, Liu, H, Liu, J, Liyanage, AH, Mack, D, and Magee, J

Subjects
nucl-ex, hep-ex
Abstract

We present new precision measurements of the elastic electron-protonscattering cross section for momentum transfer (Q$^2$) up to 15.75~\gevsq.Combined with existing data, these provide an improved extraction of the protonmagnetic form factor at high Q$^2$ and double the range over which alongitudinal/transverse separation of the cross section can be performed. Thedifference between our results and polarization data agrees with that observedat lower Q$^2$ and attributed to hard two-photon exchange (TPE) effects,extending to 8~(GeV/c)$^2$ the range of Q$^2$ for which a discrepancy isestablished at $>$95\% confidence. We use the discrepancy to quantify the sizeof TPE contributions needed to explain the cross section at high Q$^2$.

Published
2021

33. 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, JP, Chirapatpimol, K, Cisbani, E, Dalton, MM, 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, JO, Shabestari, MH, Higinbotham, DW, Huang, M, Iqbal, S, Jin, G, Kalantarians, N, Kang, H, Kelleher, A, Korover, I, Lerose, J, Leckey, J, Li, S, Lindgren, R, Long, E, Mammei, J, Margaziotis, DJ, Markowitz, P, Meekins, D, Meziani, ZE, Michaels, R, Mihovilovic, M, Muangma, N, Camacho, CM, Norum, BE, Nuruzzaman, Pan, K, Phillips, S, Piasetzky, E, Pomerantz, I, Posik, M, Punjabi, V, Qian, X, Qiang, Y, Qiu, X, Reimer, PE, Rakhman, A, Riordan, S, Ron, G, Rondon-Aramayo, O, Saha, A, Selvy, L, Shahinyan, A, Shneor, R, Širca, S, Slifer, K, Solvignon, P, Sparveris, N, Subedi, R, Sulkosky, V, Wang, D, Watson, JW, Weinstein, LB, Wojtsekhowski, B, Wood, SA, Yaron, I, Zhan, X, Zhang, J, and Zhang, YW

Subjects
nucl-ex
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 Ca48 to Ca40 in a kinematic region dominated by SRCs we provide a new way to study the isospin structure of SRCs.

Published
2020

34. Deep exclusive electroproduction of $π^0$ at high $Q^2$ in the quark valence regime

Author

Collaboration, The Jefferson Lab Hall A, Dlamini, M, Karki, B, Ali, SF, Lin, P-J, Georges, F, Ko, H-S, Israel, N, Rashad, MNH, Stefanko, A, Adikaram, D, Ahmed, Z, Albataineh, H, Aljawrneh, B, Allada, K, Allison, S, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Biswas, D, Brash, E, Bulumulla, D, Campbell, J, Camsonne, A, Carmignotto, M, Castellano, J, Chen, C, Chen, J-P, Chetry, T, Christy, ME, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Dusa, S Covrig, Crowe, B, Danagoulian, S, Danley, T, Persio, F De, Deconinck, W, Defurne, M, Desnault, C, Di, D, Duer, M, Duran, B, Ent, R, Fanelli, C, Franklin, G, Fuchey, E, Gal, C, Gaskell, D, Gautam, T, Glamazdin, O, Gnanvo, K, Gray, VM, Gu, C, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, C, Ibrahim, H, Jen, C-M, Jin, K, Jones, M, Kabir, A, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, W, Liu, J, Liu, H, Liyanage, A, Magee, J, Malace, S, Mammei, J, Markowitz, P, McClellan, E, and Meddi, F

Subjects
hep-ex, nucl-ex
Abstract

We report measurements of the exclusive neutral pion electroproduction crosssection off protons at large values of $x_B$ (0.36, 0.48 and 0.60) and $Q^2$(3.1 to 8.4 GeV$^2$) obtained from Jefferson Lab Hall A experiment E12-06-014.The corresponding structure functions $d\sigma_L/dt+\epsilon d\sigma_T/dt$,$d\sigma_{TT}/dt$, $d\sigma_{LT}/dt$ and $d\sigma_{LT'}/dt$ are extracted as afunction of the proton momentum transfer $t-t_{min}$. The results suggest theamplitude for transversely polarized virtual photons continues to dominate thecross-section throughout this kinematic range. The data are well described bycalculations based on transversity Generalized Parton Distributions coupled toa helicity flip Distribution Amplitude of the pion, thus providing a unique wayto probe the structure of the nucleon.

Published
2020

35. Measurement of the 3He Spin-Structure Functions and of Neutron (3He) Spin-Dependent Sum Rules at 0.035<Q^2<0.24 GeV^2

Author

Sulkosky, V., Singh, J. T., Peng, C., Chen, J. -P., Deur, A., Abrahamyan, S., Aniol, K. A., Armstrong, D. S., Averett, T., Bailey, S. L., Beck, A., Bertin, P., Butaru, F., Boeglin, W., Camsonne, A., Cates, G. D., Chang, C. C., Choi, Seonho, Chudakov, E., Coman, L., Cornejo, J. C, Craver, B., Cusanno, F., De Leo, R., de Jager, C. W., Denton, J. D., Dhamija, S., Feuerbach, R., Finn, J. M., Frullani, S., Fuoti, K., Gao, H., Garibaldi, F., Gayou, O., Gilman, R., Glamazdin, A., Glashausser, C., Gomez, J., Hansen, J. -O., Hayes, D., Hersman, B., Higinbotham, D. W., Holmstrom, T., Humensky, T. B., Hyde, C. E., Ibrahim, H., Iodice, M., Jiang, X., Kaufman, L. J., Kelleher, A., Keister, K. E., Kim, W., Kolarkar, A., Kolb, N., Korsch, W., Kramer, K., Kumbartzki, G., Lagamba, L., Laine, V., Laveissiere, G., Lerose, J. J., Lhuillier, D., Lindgren, R., Liyanage, N., Lu, H. -J., Ma, B., Margaziotis, D. J., Markowitz, P., McCormick, K., Meziane, M., Meziani, Z. -E., Michaels, R., Moffit, B., Monaghan, P., Nanda, S., Niedziela, J., Niskin, M., Pandolfi, R., Paschke, K. D., Potokar, M., Puckett, A., Punjabi, V. A., Qiang, Y., Ransome, R., Reitz, B., Roche, R., Saha, A., Shabetai, A., Sirca, S., Slifer, K., Snyder, R., Solvignon, P., Stringer, R., Subedi, R., Tobias, W. A., Ton, N., Ulmer, P. E., Urciuoli, G. M., Vacheret, A., Voutier, E., Wang, K., Wan, L., Wojtsekhowski, B., Woo, S., Yao, H., Yuan, J., Zhan, X., Zheng, X., and Zhu, L.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The spin-structure functions $g_1$ and $g_2$, and the spin-dependent partial cross-section $\sigma_\mathrm{TT}$ have been extracted from the polarized cross-sections differences, $\Delta \sigma_{\parallel}\hspace{-0.06cm}\left(\nu,Q^{2}\right)$ and $\Delta \sigma_{\perp}\hspace{-0.06cm}\left(\nu,Q^{2}\right)$ measured for the $\vec{^\textrm{3}\textrm{He}}(\vec{\textrm{e}},\textrm{e}')\textrm{X}$ reaction, in the E97-110 experiment at Jefferson Lab. Polarized electrons with energies from 1.147 to 4.404 GeV were scattered at angles of 6$^{\circ}$ and 9$^{\circ}$ from a longitudinally or transversely polarized $^{3}$He target. The data cover the kinematic regions of the quasi-elastic, resonance production and beyond. From the extracted spin-structure functions, the first moments $\overline{\Gamma_1}\hspace{-0.06cm}\left(Q^{2}\right)$, $\Gamma_2\hspace{-0.06cm}\left(Q^{2}\right)$ and $I_{\mathrm{TT}}\hspace{-0.06cm}\left(Q^{2}\right)$ are evaluated with high precision for the neutron in the $Q^2$ range from 0.035 to 0.24~GeV$^{2}$. The comparison of the data and the chiral effective field theory predictions reveals the importance of proper treatment of the $\Delta$ degree of freedom for spin observables., Comment: 7 pages, 5 figures, 3 tables. Version published in Phys. Lett. B

Published
2019
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36. 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

37. Comparing proton momentum distributions in $A=2$ and 3 nuclei via $^2$H $^3$H and $^3$He $(e, e'p)$ measurements

Author

Cruz-Torres, R., Li, S., Hauenstein, F., Schmidt, A., Nguyen, D., Abrams, D., Albataineh, H., Alsalmi, S., Androic, D., Aniol, K., Armstrong, W., Arrington, J., Atac, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Beck, A., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Blyth, D., Boeglin, W., Bulumulla, D., Camsonne, A., Castellanos, J., Chen, J. -P., Cohen, E. O., Covrig, S., Craycraft, K., Dongwi, B., Duer, M., Duran, B., Dutta, D., Fuchey, E., Gal, C., Gautam, T. N., Gilad, S., Gnanvo, K., Gogami, T., Gomez, J., Gu, C., Habarakada, A., Hague, T., Hansen, O., Hattawy, M., Hen, O., Higinbotham, D. W., Hughes, E., Hyde, C., Ibrahim, H., Jian, S., Joosten, S., Karki, A., Karki, B., Katramatou, A. T., Keppel, C., Khachatryan, M., Khachatryan, V., Khanal, A., King, D., King, P., Korover, I., Kutz, T., Lashley-Colthirst, N., Laskaris, G., Li, W., Liu, H., Liyanage, N., Lonardoni, D., Machleidt, R., Marcucci, L. E., Markowitz, P., McClellan, R. E., Meekins, D., Beck, S. Mey-Tal, Meziani, Z. -E., Michaels, R., Mihovilovic, M., Nelyubin, V., Nuruzzaman, N., Nycz, M., Obrecht, R., Olson, M., Ou, L., Owen, V., Pandey, B., Pandey, V., Papadopoulou, A., Park, S., Patsyuk, M., Paul, S., Petratos, G. G., Piasetzky, E., Pomatsalyuk, R., Premathilake, S., Puckett, A. J. R., Punjabi, V., Ransome, R., Rashad, M. N. H., Reimer, P. E., Riordan, S., Roche, J., Sammarruca, F., Santiesteban, N., Sawatzky, B., Segarra, E. P., Schmookler, B., Shahinyan, A., Širch, S., Sparveris, N., Su, T., Suleiman, R., Szumila-Vance, H., Tadepalli, A. S., Tang, L., Tireman, W., Tortorici, F., Urciuoli, G., Viviani, M., Weinstein, L. B., Wojtsekhowski, B., Wood, S., Ye, Z. H., Ye, Z. Y., and Zhang, J.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We report the first measurement of the $(e,e'p)$ reaction cross-section ratios for Helium-3 ($^3$He), Tritium ($^3$H), and Deuterium ($d$). The measurement covered a missing momentum range of $40 \le p_{miss} \le 550$ MeV$/c$, at large momentum transfer ($\langle Q^2 \rangle \approx 1.9$ (GeV$/c$)$^2$) and $x_B>1$, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for $^3$He$/d$ and $^3$H$/d$ extend to just above the typical nucleon Fermi-momentum ($k_F \approx 250$ MeV$/c$) and differ from each other by $\sim 20\%$, while for $^3$He/$^3$H they agree within the measurement accuracy of about 3\%. At momenta above $k_F$, the measured $^3$He/$^3$H ratios differ from the calculation by $20\% - 50\%$. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the $^3$He/$^3$H cross-section ratio for this measurement by less than 5\%. If these calculations are correct, then the differences at large missing momenta between the $^3$He/$^3$H experimental and calculated ratios could be due to the underlying $NN$ interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the $NN$ interaction., Comment: 8 pages, 3 figures (4 panels)

Published
2019
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38. Probing Few-Body Nuclear Dynamics via H3 and He3 (e,e′p)pn Cross-Section Measurements

Author

Cruz-Torres, R, Nguyen, D, Hauenstein, F, Schmidt, A, Li, S, Abrams, D, Albataineh, H, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Benmokhtar, F, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, J-P, Cohen, EO, Covrig, S, Craycraft, K, Dongwi, B, Duer, M, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Golak, J, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, O, Hattawy, M, Hen, O, Higinbotham, DW, Hughes, E, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Kamada, H, Karki, A, Karki, B, Katramatou, AT, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, King, D, King, P, Korover, I, Kutz, T, Lashley-Colthirst, N, Laskaris, G, Li, W, Liu, H, Liyanage, N, Markowitz, P, McClellan, RE, Meekins, D, Beck, S Mey-Tal, Meziani, Z-E, Michaels, R, Mihovilovič, M, Nelyubin, V, Nuruzzaman, N, Nycz, M, Obrecht, R, Olson, M, Ou, L, Owen, V, Pandey, B, Pandey, V, Papadopoulou, A, Park, S, Patsyuk, M, Paul, S, Petratos, GG, Piasetzky, E, Pomatsalyuk, R, Premathilake, S, Puckett, AJR, and Punjabi, V

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Jefferson Lab Hall A Tritium Collaboration, nucl-ex, nucl-th, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9  (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500  MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full p_{miss} range for ^{3}H and for 100≤p_{miss}≤350  MeV/c for ^{3}He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at p_{miss}>250  MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of ^{3}He plus ^{3}H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire p_{miss} range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500  MeV/c.

Published
2020

39. Probing Few-Body Nuclear Dynamics via ^{3}H and ^{3}He (e,e^{'}p)pn Cross-Section Measurements.

Author

Cruz-Torres, R, Nguyen, D, Hauenstein, F, Schmidt, A, Li, S, Abrams, D, Albataineh, H, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Ayerbe Gayoso, C, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Benmokhtar, F, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, J-P, Cohen, EO, Covrig, S, Craycraft, K, Dongwi, B, Duer, M, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Golak, J, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, O, Hattawy, M, Hen, O, Higinbotham, DW, Hughes, E, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Kamada, H, Karki, A, Karki, B, Katramatou, AT, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, King, D, King, P, Korover, I, Kutz, T, Lashley-Colthirst, N, Laskaris, G, Li, W, Liu, H, Liyanage, N, Markowitz, P, McClellan, RE, Meekins, D, Mey-Tal Beck, S, Meziani, Z-E, Michaels, R, Mihovilovič, M, Nelyubin, V, Nuruzzaman, N, Nycz, M, Obrecht, R, Olson, M, Ou, L, Owen, V, Pandey, B, Pandey, V, Papadopoulou, A, Park, S, Patsyuk, M, Paul, S, Petratos, GG, Piasetzky, E, Pomatsalyuk, R, Premathilake, S, Puckett, AJR, and Punjabi, V

Subjects
Jefferson Lab Hall A Tritium Collaboration, nucl-ex, nucl-th, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract

We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9  (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500  MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full p_{miss} range for ^{3}H and for 100≤p_{miss}≤350  MeV/c for ^{3}He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at p_{miss}>250  MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of ^{3}He plus ^{3}H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire p_{miss} range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500  MeV/c.

Published
2020

40. Exclusive π+ electroproduction off the proton from low to high -t

Author

Basnet, S, Huber, GM, Li, WB, Blok, HP, Gaskell, D, Horn, T, Aniol, K, Arrington, J, Beise, EJ, Boeglin, W, Brash, EJ, Breuer, H, Chang, CC, Christy, ME, Ent, R, Gibson, E, Holt, RJ, Jin, S, Jones, MK, Keppel, CE, Kim, W, King, PM, Kovaltchouk, V, Liu, J, Lolos, GJ, MacK, DJ, Margaziotis, DJ, Markowitz, P, Matsumura, A, Meekins, D, Miyoshi, T, Mkrtchyan, H, Niculescu, I, Okayasu, Y, Pentchev, L, Perdrisat, C, Potterveld, D, Punjabi, V, Reimer, P, Reinhold, J, Roche, J, Sarty, A, Smith, GR, Tadevosyan, V, Tang, LG, Tvaskis, V, Volmer, J, Vulcan, W, Warren, G, Wood, SA, Xu, C, and Zheng, X

Subjects
nucl-ex, hep-ex
Abstract

Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. Purpose: To study the transition between nonperturbative and perturbative quantum chromodynamics as the square of four-momentum transfer to the struck proton, -t, is increased. Method: Cross sections for the H1(e,e′π+)n reaction were measured over the -t range of 0.272 to 2.127 GeV2 with limited azimuthal coverage at fixed beam energy of 4.709 GeV, Q2 of 2.4 GeV2, and W of 2.0 GeV at the Thomas Jefferson National Accelerator Facility (JLab) Hall C. Results: The -t dependence of the measured π+ electroproduction cross section generally agrees with prior data from JLab Halls B and C. The data are consistent with a Regge amplitude-based theoretical model but show poor agreement with a generalized parton distribution-based model. Conclusion: The agreement of cross sections with prior data implies small contribution from the interference terms, and the confirmation of the change in t slopes between the low- and high - t regions previously observed in photoproduction indicates the changing nature of the electroproduction reaction in our kinematic regime.

Published
2019

41. Exclusive π+ electroproduction off the proton from low to high −t

Author

Basnet, S, Huber, GM, Li, WB, Blok, HP, Gaskell, D, Horn, T, Aniol, K, Arrington, J, Beise, EJ, Boeglin, W, Brash, EJ, Breuer, H, Chang, CC, Christy, ME, Ent, R, Gibson, E, Holt, RJ, Jin, S, Jones, MK, Keppel, CE, Kim, W, King, PM, Kovaltchouk, V, Liu, J, Lolos, GJ, Mack, DJ, Margaziotis, DJ, Markowitz, P, Matsumura, A, Meekins, D, Miyoshi, T, Mkrtchyan, H, Niculescu, I, Okayasu, Y, Pentchev, L, Perdrisat, C, Potterveld, D, Punjabi, V, Reimer, P, Reinhold, J, Roche, J, Sarty, A, Smith, GR, Tadevosyan, V, Tang, LG, Tvaskis, V, Volmer, J, Vulcan, W, Warren, G, Wood, SA, Xu, C, and Zheng, X

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, nucl-ex, hep-ex, Nuclear and plasma physics
Abstract

Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. Purpose: To study the transition between nonperturbative and perturbative quantum chromodynamics as the square of four-momentum transfer to the struck proton, -t, is increased. Method: Cross sections for the H1(e,e′π+)n reaction were measured over the -t range of 0.272 to 2.127 GeV2 with limited azimuthal coverage at fixed beam energy of 4.709 GeV, Q2 of 2.4 GeV2, and W of 2.0 GeV at the Thomas Jefferson National Accelerator Facility (JLab) Hall C. Results: The -t dependence of the measured π+ electroproduction cross section generally agrees with prior data from JLab Halls B and C. The data are consistent with a Regge amplitude-based theoretical model but show poor agreement with a generalized parton distribution-based model. Conclusion: The agreement of cross sections with prior data implies small contribution from the interference terms, and the confirmation of the change in t slopes between the low- and high - t regions previously observed in photoproduction indicates the changing nature of the electroproduction reaction in our kinematic regime.

Published
2019

42. Unique Access to u-Channel Physics: Exclusive Backward-Angle Omega Meson Electroproduction

Author

Li, WB, Huber, GM, Blok, HP, Gaskell, D, Horn, T, Semenov-Tian-Shansky, K, Pire, B, Szymanowski, L, Laget, J-M, Aniol, K, Arrington, J, Beise, EJ, Boeglin, W, Brash, EJ, Breuer, H, Chang, CC, Christy, ME, Ent, R, Gibson, EF, Holt, RJ, Jin, S, Jones, MK, Keppel, CE, Kim, W, King, PM, Kovaltchouk, V, Liu, J, Lolos, GJ, Mack, DJ, Margaziotis, DJ, Markowitz, P, Matsumura, A, Meekins, D, Miyoshi, T, Mkrtchyan, H, Niculescu, I, Okayasu, Y, Pentchev, L, Perdrisat, C, Potterveld, D, Punjabi, V, Reimer, PE, Reinhold, J, Roche, J, Roos, PG, Sarty, A, Smith, GR, Tadevosyan, V, Tang, LG, Tvaskis, V, Volmer, J, Vulcan, W, Warren, G, Wood, SA, Xu, C, and Zheng, X

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Jefferson Lab Fπ Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

Backward-angle meson electroproduction above the resonance region, which was previously ignored, is anticipated to offer unique access to the three quark plus sea component of the nucleon wave function. In this Letter, we present the first complete separation of the four electromagnetic structure functions above the resonance region in exclusive ω electroproduction off the proton, ep→e^{'}pω, at central Q^{2} values of 1.60, 2.45  GeV^{2}, at W=2.21  GeV. The results of our pioneering -u≈-u_{min} study demonstrate the existence of a unanticipated backward-angle cross section peak and the feasibility of full L/T/LT/TT separations in this never explored kinematic territory. At Q^{2}=2.45  GeV^{2}, the observed dominance of σ_{T} over σ_{L}, is qualitatively consistent with the collinear QCD description in the near-backward regime, in which the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes: universal nonperturbative objects only accessible through backward-angle kinematics.

Published
2019

43. Comparing proton momentum distributions in A = 2 and 3 nuclei via 2H 3H and 3He (e,e′p) measurements

Author

Cruz-Torres, R, Li, S, Hauenstein, F, Schmidt, A, Nguyen, D, Abrams, D, Albataineh, H, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Ayerbe Gayoso, C, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, JP, Cohen, EO, Covrig, S, Craycraft, K, Dongwi, B, Duer, M, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, O, Hattawy, M, Hen, O, Higinbotham, DW, Hughes, E, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Karki, A, Karki, B, Katramatou, AT, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, King, D, King, P, Korover, I, Kutz, T, Lashley-Colthirst, N, Laskaris, G, Li, W, Liu, H, Liyanage, N, Lonardoni, D, Machleidt, R, Marcucci, LE, Markowitz, P, McClellan, RE, Meekins, D, Mey-Tal Beck, S, Meziani, ZE, Michaels, R, Mihovilovič, M, Nelyubin, V, Nuruzzaman, N, Nycz, M, Obrecht, R, Olson, M, Ou, L, Owen, V, Pandey, B, Pandey, V, Papadopoulou, A, Park, S, Patsyuk, M, Paul, S, Petratos, GG, Piasetzky, E, Pomatsalyuk, R, Premathilake, S, Puckett, AJR, and Punjabi, V

Subjects
nucl-ex, nucl-th, Nuclear & Particles Physics, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

We report the first measurement of the (e,e′p) reaction cross-section ratios for Helium-3 (He3), Tritium (H3), and Deuterium (d). The measurement covered a missing momentum range of 40≤pmiss≤550MeV/c, at large momentum transfer (〈Q2〉≈1.9 (GeV/c)2) and xB>1, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for He3/d and H3/d extend to just above the typical nucleon Fermi-momentum (kF≈250 MeV/c) and differ from each other by ∼20%, while for He3/H3 they agree within the measurement accuracy of about 3%. At momenta above kF, the measured He3/H3 ratios differ from the calculation by 20%−50%. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the He3/H3 cross-section ratio for this measurement by less than 5%. If these calculations are correct, then the differences at large missing momenta between the He3/H3 experimental and calculated ratios could be due to the underlying NN interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the NN interaction.

Published
2019

44. Comparing proton momentum distributions in A = 2 and 3 nuclei via 2H 3H and 3He (e,e′p) measurements

Author

Collaboration, Jefferson Lab Hall A Tritium, Cruz-Torres, R, Li, S, Hauenstein, F, Schmidt, A, Nguyen, D, Abrams, D, Albataineh, H, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, J-P, Cohen, EO, Covrig, S, Craycraft, K, Dongwi, B, Duer, M, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, O, Hattawy, M, Hen, O, Higinbotham, DW, Hughes, E, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Karki, A, Karki, B, Katramatou, AT, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, King, D, King, P, Korover, I, Kutz, T, Lashley-Colthirst, N, Laskaris, G, Li, W, Liu, H, Liyanage, N, Lonardoni, D, Machleidt, R, Marcucci, LE, Markowitz, P, McClellan, RE, Meekins, D, Beck, S Mey-Tal, Meziani, Z-E, Michaels, R, Mihovilovič, M, Nelyubin, V, Nuruzzaman, N, Nycz, M, Obrecht, R, Olson, M, Ou, L, Owen, V, Pandey, B, Pandey, V, Papadopoulou, A, Park, S, Patsyuk, M, Paul, S, Petratos, GG, Piasetzky, E, Pomatsalyuk, R, Premathilake, S, and Puckett, AJR

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, nucl-ex, nucl-th, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract

We report the first measurement of the (e,e′p) reaction cross-section ratios for Helium-3 (He3), Tritium (H3), and Deuterium (d). The measurement covered a missing momentum range of 40≤pmiss≤550MeV/c, at large momentum transfer (〈Q2〉≈1.9 (GeV/c)2) and xB>1, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for He3/d and H3/d extend to just above the typical nucleon Fermi-momentum (kF≈250 MeV/c) and differ from each other by ∼20%, while for He3/H3 they agree within the measurement accuracy of about 3%. At momenta above kF, the measured He3/H3 ratios differ from the calculation by 20%−50%. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the He3/H3 cross-section ratio for this measurement by less than 5%. If these calculations are correct, then the differences at large missing momenta between the He3/H3 experimental and calculated ratios could be due to the underlying NN interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the NN interaction.

Published
2019

45. High-resolution hypernuclear spectroscopy at Jefferson Lab, Hall A

Author

Jefferson Lab Hall A Collaboration, Garibaldi, F., Acha, A., Ambrozewicz, P., Aniol, K. A., Beturin, P., Benaoum, H., Benesch, J., Bertin, P. Y., Blomqvist, K. I., Boeglin, W. U., Breuer, H., Brindza, P., Bydzovsky, P., Camsonne, A., Chang, C. C., Chen, J. -P., Choi, Seonho, Chudakov, E. A., Cisbani, E., Colilli, S., Coman, L., Cusanno, F., Craver, B. J., De Cataldo, G., de Jager, C. W., De Leo, R., Deur, A. P., Ferdi, C., Feuerbach, R. J., Folts, E., Frullani, S., Gayou, O., Giuliani, F., Gomez, J., Gricia, M., Hansen, J. O., Hayes, D., Higinbotham, D. W., Holmstrom, T. K., Hyde, C. E., Ibrahim, H. F., Iodice, M., Jiang, X., Kaufman, L. J., Kino, K., Kross, B., Lagamba, L., LeRose, J. J., Lindgren, R. A., Lucentini, M., Margaziotis, D. J., Markowitz, P., Marrone, S., Meekins, D. G., Meziani, Z. E., McCormick, K., Michaels, R. W., Millener, D. J., Miyoshi, T., Moffit, B., Monaghan, P. A., Moteabbed, M., Camacho, C. Munoz, Nanda, S., Nappi, E., Nelyubin, V. V., Norum, B. E., Okasyasu, Y., Paschke, K. D., Perdrisat, C. F., Piasetzky, E., Punjabi, V. A., Qiang, Y., Raue, B., Reimer, P. E., Reinhold, J., Reitz, B., Roche, R. E., Rodriguez, V. M., Saha, A., Santavenere, F., Sarty, A. J., Segal, J., Shahinyan, A., Singh, J., Sirca, S., Snyder, R., Solvignon, P. H., Sotona, M., Subedi, R., Sulkosky, V. A., Suzuki, T., Ueno, H., Ulmer, P. E., Urciuoli, G. M., Voutier, E., Wojtsekhowski, B. B., Zheng, X., and Zorn, C.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The experiment E94-107 in Hall A at Jefferson Lab started a systematic study of high resolution hypernuclear spectroscopy in the 0p-shell region of nuclei such as the hypernuclei produced in electroproduction on 9Be, 12C and 16O targets. In order to increase counting rates and provide unambiguous kaon identification two superconducting septum magnets and a ring-imaging Cherenkov detector were added to the Hall A standard equipment. The high-quality beam, the good spectrometers and the new experimental devices allowed us to obtain very good results. For the first time, measurable strength with sub-MeV energy resolution was observed for the core-excited states of Lambda 12B. A high-quality Lambda 16N hypernuclear spectrum was likewise obtained. A first measurement of the Lambda binding energy for Lambda 16N, calibrated against the elementary reaction on hydrogen, was obtained with high precision, 13.76 +/- 0.16 MeV. Similarly, the first Lambda 9Li hypernuclear spectrum shows general agreement with theory (distorted-wave impulse approximation with the SLA and BS3 electroproduction models and shell-model wave functions). Some disagreement exists with respect to the relative strength of the states making up the first multiplet. A Lambda separation energy of 8.36 MeV was obtained, in agreement with previous results. It has been shown that the electroproduction of hypernuclei can provide information complementary to that obtained with hadronic probes and the gamma-ray spectroscopy technique., Comment: 27 pages, 18 figures, submitted to Physical Review C

Published
2018
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46. Separated Kaon Electroproduction Cross Section and the Kaon Form Factor from 6 GeV JLab Data

Author

Carmignotto, M., Ali, S., Aniol, K., Arrington, J., Barrett, B., Beise, E. J., Blok, H. P., Boeglin, W., Brash, E. J., Breuer, H., Chang, C. C., Christy, M. E., Dittmann, A., Ent, R., Fenker, H., Gaskell, D., Gibson, E., Holt, R. J., Horn, T., Huber, G. M., Jin, S., Jones, M. K., Keppel, C. E., Kim, W., King, P. M., Kovaltchouk, V., Liu, J., Lolos, G. J., Mack, D. J., Margaziotis, D. J., Markowitz, P., Matsumura, A., Meekins, D., Miyoshi, T., Mkrtchyan, H., Niculescu, G., Niculescu, I., Okayasu, Y., Pegg, I., Pentchev, L., Perdrisat, C., Potterveld, D., Punjabi, V., Reimer, P. E., Reinhold, J., Roche, J., Sarty, A., Smith, G. R., Tadevosyan, V., Tang, L. G., Trotta, R., Tvaskis, V., Vargas, A., Vidakovic, S., Volmer, J., Vulcan, W., Warren, G., Wood, S. A., Xu, C., and Zheng, X.

Subjects
Nuclear Experiment
Abstract

The $^{1}H$($e,e^\prime K^+$)$\Lambda$ reaction was studied as a function of the Mandelstam variable $-t$ using data from the E01-004 (FPI-2) and E93-018 experiments that were carried out in Hall C at the 6 GeV Jefferson Lab. The cross section was fully separated into longitudinal and transverse components, and two interference terms at four-momentum transfers $Q^2$ of 1.00, 1.36 and 2.07 GeV$^2$. The kaon form factor was extracted from the longitudinal cross section using the Regge model by Vanderhaeghen, Guidal, and Laget. The results establish the method, previously used successfully for pion analyses, for extracting the kaon form factor. Data from 12 GeV Jefferson Lab experiments are expected to have sufficient precision to distinguish between theoretical predictions, for example recent perturbative QCD calculations with modern parton distribution amplitudes. The leading-twist behavior for light mesons is predicted to set in for values of $Q^2$ between 5-10 GeV$^2$, which makes data in the few GeV regime particularly interesting. The $Q^2$ dependence at fixed $x$ and $-t$ of the longitudinal cross section we extracted seems consistent with the QCD factorization prediction within the experimental uncertainty.

Published
2018
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47. 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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48. 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, DW, Boyd, C, Gadsby, A, Gilad, S, Saha, A, Udias, JM, Goodwill, JS, 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, MM, 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, DJ, 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, PE, 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, JW, and Weinstein, LB

Subjects
nucl-ex
Abstract

Experimental cross sections for the $^4He(e,e'p)X$ reaction up to a missingmomentum 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 ImpulseApproximation(RDWIA) calculations for $^4He(e,e'p)^3H$ channel. Significantlymore 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 ofinitial-state multi-nucleon correlations are stronger than expected by theRDWIA model.

Published
2019

49. Polarization Transfer Observables in Elastic Electron Proton Scattering at $Q^2 = $2.5, 5.2, 6.8, and 8.5 GeV$^2$

Author

Puckett, A. J. R., Brash, E. J., Jones, M. K., Luo, W., Meziane, M., Pentchev, L., Perdrisat, C. F., Punjabi, V., Wesselmann, F. R., Afanasev, A., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, E., Commisso, M., Cornejo, J. C., Covrig, S., Danagoulian, S., Daniel, A., Davidenko, A., Day, D., Dhamija, S., Dutta, D., Ent, R., Frullani, S., Fenker, H., Frlez, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Marsh, A., Matulenko, Y., Maxwell, J., Mbianda, G., Meekins, D., Melnik, Y., Miller, J., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Moreno, O., Mulholland, J., Narayan, A., Nedev, S., Nuruzzaman, Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Subedi, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wojtsekhowski, B. B., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The GEp-III and GEp-2$\gamma$ experiments were carried out in Jefferson Lab's (JLab's) Hall C from 2007-2008, to extend the knowledge of $G_E^p/G_M^p$ to the highest practically achievable $Q^2$ and to search for effects beyond the Born approximation in polarization transfer observables of elastic $\vec{e}p$ scattering. This article reports an expanded description of the common experimental apparatus and data analysis procedure, and the results of a final reanalysis of the data from both experiments, including the previously unpublished results of the full-acceptance data of the GEp-2$\gamma$ experiment. The Hall C High Momentum Spectrometer detected and measured the polarization of protons recoiling elastically from collisions of JLab's polarized electron beam with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered electrons in coincidence to suppress inelastic backgrounds. The final GEp-III data are largely unchanged relative to the originally published results. The statistical uncertainties of the final GEp-2$\gamma$ data are significantly reduced at $\epsilon = 0.632$ and $0.783$ relative to the original publication. The decrease with $Q^2$ of $G_E^p/G_M^p$ continues to $Q^2 = 8.5$ GeV$^2$, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At $Q^2 = 2.5$ GeV$^2$, the proton form factor ratio $G_E^p/G_M^p$ shows no statistically significant $\epsilon$-dependence, as expected in the Born approximation. The ratio $P_\ell/P_\ell^{Born}$ of the longitudinal polarization transfer component to its Born value shows an enhancement of roughly 1.4\% at $\epsilon = 0.783$ relative to $\epsilon = 0.149$, with $\approx 1.9\sigma$ significance based on the total uncertainty, implying a similar effect in the transverse component $P_t$ that cancels in the ratio $R$., Comment: 44 pages, 28 figures. Archival publication for the GEp-III and GEp-2gamma experiments that ran in Jefferson Lab's experimental Hall C from October, 2007 to June, 2008. v2: final manuscript as accepted by PRC. v3: Replaced figures 13 and 19 with corrected versions from published Erratum. Also made minor corrections to the text and to Table XI reflecting the corrections in the published Erratum

Published
2017
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50. Technical Supplement to 'Polarization Transfer Observables in Elastic Electron-Proton Scattering at Q$^2$ = 2.5, 5.2, 6.8, and 8.5 GeV$^2$'

Author

Puckett, A. J. R., Brash, E. J., Jones, M. K., Luo, W., Meziane, M., Pentchev, L., Perdrisat, C. F., Punjabi, V., Wesselmann, F. R., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, E., Commisso, M., Cornejo, J. C., Covrig, S., Danagoulian, S., Daniel, A., Davidenko, A., Day, D., Dhamija, S., Dutta, D., Ent, R., Frullani, S., Fenker, H., Frlez, E., Garibaldi, F., Gaskell, D., Gilad, S., Gilman, R., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Marsh, A., Matulenko, Y., Maxwell, J., Mbianda, G., Meekins, D., Melnik, Y., Miller, J., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Moreno, O., Mulholland, J., Narayan, A., Nedev, S., Nurruzzaman, Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Subedi, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wojtsekhowski, B. B., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The GEp-III and GEp-2$\gamma$ experiments, carried out in Jefferson Lab's Hall C from 2007-2008, consisted of measurements of polarization transfer in elastic electron-proton scattering at momentum transfers of $Q^2 = 2.5, 5.2, 6.8,$ and $8.54$ GeV$^2$. These measurements were carried out to improve knowledge of the proton electromagnetic form factor ratio $R = \mu_p G_E^p/G_M^p$ at large values of $Q^2$ and to search for effects beyond the Born approximation in polarization transfer observables at $Q^2 = 2.5$ GeV$^2$. The final results of both experiments were reported in a recent archival publication. A full reanalysis of the data from both experiments was carried out in order to reduce the systematic and, for the GEp-2$\gamma$ experiment, statistical uncertainties. This technical note provides additional details of the final analysis omitted from the main publication, including the final evaluation of the systematic uncertainties., Comment: 33 pages, 33 figures. v3 = Final manuscript as accepted for publication in Nuclear Instruments and Methods Section A (in press)

Published
2017
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