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137 results on '"Cornejo, J. C."'

1. Ultra-High precision Compton polarimetry at 2 GeV

Author

Zec, A., Premathilake, S., Cornejo, J. C., Dalton, M. M., Gal, C., Gaskell, D., Gericke, M., Halilovic, I., Liu, H., Mammei, J., Michaels, R., Palatchi, C., Pan, J., Paschke, K. D., Quinn, B., and Zhang, J.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

We report a high precision measurement of electron beam polarization using Compton polarimetry. The measurement was made in experimental Hall A at Jefferson Lab during the CREX experiment in 2020. A total uncertainty of dP/P=0.36% was achieved detecting the back-scattered photons from the Compton scattering process. This is the highest accuracy in a measurement of electron beam polarization using Compton scattering ever reported, surpassing the ground-breaking measurement from the SLAC Large Detector (SLD) Compton polarimeter. Such uncertainty reaches the level required for the future flagship measurements to be made by the MOLLER and SoLID experiments.

Published
2024
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2. 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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3. 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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4. First Determination of the 27Al Neutron Distribution Radius from a Parity-Violating Electron Scattering Measurement

Author

QWeak Collaboration, Androic, D., Armstrong, D. S., Bartlett, K., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cornejo, J. C., Dusa, S. Covrig, Dalton, M. M., Davis, C. A., Deconinck, W., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gal, C., Gaskell, D., Gericke, M. T. W., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Jones, D. C., Jones, M. K., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mei, J., Mesick, K. E., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuruzzaman, van Oers, W. T. H, Owen, V. F., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Radloff, R. W., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Zang, P., Zhamkochyan, S., Christy, M. E., Horowitz, C. J., Fattoyev, F. J., and Lin, Z.

Subjects
Nuclear Experiment
Abstract

We report the first measurement of the parity-violating elastic electron scattering asymmetry on 27Al. The 27Al elastic asymmetry is A_PV = 2.16 +- 0.11 (stat) +- 0.16 (syst) ppm, and was measured at =0.02357 +- 0.0001 GeV^2, = 7.61 +- 0.02 degrees, and = 1.157 GeV with the Qweak apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the 27Al neutron radius R_n = 2.89 +- 0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_n-R_p = -0.04 +- 0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the 27Al weak radius R_w = 3.00 +- 0.15 fm, and the weak skin thickness R_wk - R_ch = -0.04 +- 0.15 fm. The weak form factor at this Q^2 is F_wk = 0.39 +- 0.04., Comment: Revised version after referee's comments and suggestions. Some improvements and clarification to the text, no changes to the figures, tables, results or conclusions. 7 pages, 3 figures, 3 tables

Published
2021
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5. 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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6. Measurement of the Beam-Normal Single-Spin Asymmetry for Elastic Electron Scattering from $^{12}$C and $^{27}$Al

Author

QWeak Collaboration, Androic, D., Armstrong, D. S., Asaturyan, A., Bartlett, K., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Christy, M. E., Cornejo, J. C., Dusa, S. Covrig, Dalton, M. M., Davis, C. A., Deconinck, W., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elassar, M., Falk, W. R., Finn, J. M., Forest, T., Gal, C., Gaskell, D., Gericke, M. T. W., Gray, V. M., Guo, F., Hoskins, J. R., Jones, D. C., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J. P., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mesick, K. E., Michaels, R., Mkrtchyan, A., Mkrtchyan, H., Narayan, A., Ndukum, L. Z., Nuruzzaman, Nelyubin, V., van Oers, W. T. H, Owen, V. F., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Radloff, R. W., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Tadevosyan, V., Tobias, W. A., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Zang, P., and Zhamkochyan, S.

Subjects
Nuclear Experiment
Abstract

We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of $B_n$ on $^{12}$C and provide a first measurement on $^{27}$Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average lab scattering angle for both targets was 7.7 degrees, and the average $Q^2$ for both targets was 0.02437 GeV$^2$ (Q=0.1561 GeV). The asymmetries are $B_n$ = -10.68 $\pm$ 0.90 stat) $\pm$ 0.57 (syst) ppm for $^{12}$C and $B_n$ = -12.16 $\pm$ 0.58 (stat) $\pm$ 0.62 (syst) ppm for $^{27}$Al. The results are consistent with theoretical predictions, and are compared to existing data. When scaled by Z/A, the Q-dependence of all the far-forward angle (theta < 10 degrees) data from $^{1}$H to $^{27}$Al can be described by the same slope out to $Q \approx 0.35$ GeV. Larger-angle data from other experiments in the same Q range are consistent with a slope about twice as steep., Comment: Minor changes after refereeing; version as accepted for Physical Review C. Cosmetic changes to several figures, one author added. 22 pages, 8 figures

Published
2021
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7. 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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8. 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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9. 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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10. 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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11. Precision Measurement of the Beam-Normal Single-Spin Asymmetry in Forward-Angle Elastic Electron-Proton Scattering

Author

QWeak collaboration, Androic, D., Armstrong, D. S., Asaturyan, A., Bartlett, K., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cornejo, J. C., Dusa, S. Covrig, Dalton, M. M., Davis, C. A., Deconinck, W., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gal, C., Gaskell, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Jones, D., Jones, M. K., Jones, R. T., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J. P., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mei, J., Mesick, K. E., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuruzzaman, van Oers, W. T. H, Owen, V. F., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Radloff, R. W., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Zang, P., and Zhamkochyan, S.

Subjects
Nuclear Experiment
Abstract

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of theta_lab = 7.9 degrees and a mean energy of 1.149 GeV. The asymmetry result is B_n = -5.194 +- 0.067 (stat) +- 0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (theta_lab -> 0) where they should be most reliable., Comment: 6 pages, 3 figures; Slightly revised version, after referee's comments; accepted in PRL

Published
2020
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12. Parity-Violating Inelastic Electron-Proton Scattering at Low $Q^2$ Above the Resonance Region

Author

QWeak Collaboration, Androic, D., Armstrong, D. S., Asaturyan, A., Bartlett, K., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cornejo, J. C., Dalton, M. M., Davis, C. A., Deconinck, W., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Falk, W. R., Finn, J. M., Gal, C., Gaskell, D., Gericke, M. T. W., Grames, J., Guo, F., Hoskins, J. R., Jones, D., Jones, M. K., Jones, R., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mesick, K. E., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Narayan, A., Nelyubin, V., van Oers, W. T. H, Owen, V. F., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Radloff, R. W., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Tadevosyan, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., and Zang, P.

Subjects
Nuclear Experiment, High Energy Physics - Phenomenology
Abstract

We report the measurement of the parity-violating asymmetry for the inelastic scattering of electrons from the proton, at $Q^2 = 0.082$ GeV$^2$ and $ W = 2.23$ GeV, above the resonance region. The result $A_{\rm Inel} = - 13.5 \pm 2.0 ({\rm stat}) \pm 3.9 ({\rm syst})$~ppm agrees with theoretical calculations, and helps to validate the modeling of the $\gamma Z$ interference structure functions $F_1^{\gamma Z}$ and $F_2^{\gamma Z}$ used in those calculations, which are also used for determination of the two-boson exchange box diagram ($\Box_{\gamma Z}$) contribution to parity-violating elastic scattering measurements. A positive parity-violating asymmetry for inclusive $\pi^-$ production was observed, as well as positive beam-normal single-spin asymmetry for scattered electrons and a negative beam-normal single-spin asymmetry for inclusive $\pi^-$ production., Comment: 18 pages, 9 figures, version accepted in Physical Review C

Published
2019
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13. 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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14. Precision Measurement of the Weak Charge of the Proton

Author

Androic, D., Armstrong, D. S., Asaturyan, A., Averett, T., Balewski, J., Bartlett, K., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cornejo, J. C., Dusa, S. Covrig, Dalton, M. M., Davis, C. A., Deconinck, W., Diefenbach, J., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gal, C., Gaskell, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Jones, D., Jones, M., Jones, R., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mei, J., Mesick, K. E., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuhait, H., Nuruzzaman, van Oers, W. T. H., Opper, A. K., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Poelker, M., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Young, R. D., Zang, P., and Zhamkochyan, S.

Subjects
Nuclear Experiment
Abstract

The fields of particle and nuclear physics have undertaken extensive programs to search for evidence of physics beyond that explained by current theories. The observation of the Higgs boson at the Large Hadron Collider completed the set of particles predicted by the Standard Model (SM), currently the best description of fundamental particles and forces. However, the theory's limitations include a failure to predict fundamental parameters and the inability to account for dark matter/energy, gravity, and the matter-antimater asymmetry in the universe, among other phenomena. Given the lack of additional particles found so far through direct searches in the post-Higgs era, indirect searches utilizing precise measurements of well predicted SM observables allow highly targeted alternative tests for physics beyond the SM. Indirect searches have the potential to reach mass/energy scales beyond those directly accessible by today's high-energy accelerators. The value of the weak charge of the proton Q_W^p is an example of such an indirect search, as it sets the strength of the proton's interaction with particles via the well-predicted neutral electroweak force. Parity violation (invariance under spatial inversion (x,y,z) -> (-x,-y,-z)) is violated only in the weak interaction, thus providing a unique tool to isolate the weak interaction in order to measure the proton's weak charge. Here we report Q_W^p=0.0719+-0.0045, as extracted from our measured parity-violating (PV) polarized electron-proton scattering asymmetry, A_ep=-226.5+-9.3 ppb. Our value of Q_W^p is in excellent agreement with the SM, and sets multi-TeV-scale constraints on any semi-leptonic PV physics not described within the SM., Comment: Direct link to Nature Version "https://rdcu.be/954U"

Published
2019
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15. 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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16. 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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17. A novel comparison of M{\o}ller and Compton electron-beam polarimeters

Author

Magee, J. A., Narayan, A., Jones, D., Beminiwattha, R., Cornejo, J. C., Dalton, M. M., Deconinck, W., Dutta, D., Gaskell, D., Martin, J. W., Paschke, K. D., Tvaskis, V., Asaturyan, A., Benesch, J., Cates, G., Cavness, B. S., Dillon-Townes, L. A., Hays, G., Hoskins, J., Ihloff, E., Jones, R., King, P. M., Kowalski, S., Kurchaninov, L., Lee, L., McCreary, A., McDonald, M., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Nelyubin, V., Page, S., Ramsay, W. D., Solvignon, P., Storey, D., Tobias, W. A., Urban, E., Vidal, C., Waidyawansa, B., Wang, P., and Zhamkotchyan, S.

Subjects
Physics - Instrumentation and Detectors, Nuclear Experiment
Abstract

We have performed a novel comparison between electron-beam polarimeters based on M{\o}ller and Compton scattering. A sequence of electron-beam polarization measurements were performed at low beam currents ($<$ 5 $\mu$A) during the $Q_{\rm weak}$ experiment in Hall C at Jefferson Lab. These low current measurements were bracketed by the regular high current (180 $\mu$A) operation of the Compton polarimeter. All measurements were found to be consistent within experimental uncertainties of 1% or less, demonstrating that electron polarization does not depend significantly on the beam current. This result lends confidence to the common practice of applying M{\o}ller measurements made at low beam currents to physics experiments performed at higher beam currents. The agreement between two polarimetry techniques based on independent physical processes sets an important benchmark for future precision asymmetry measurements that require sub-1% precision in polarimetry.

Published
2016
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18. First measurement of unpolarized SIDIS cross section and cross section ratios from a $^3$He target

Author

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

Subjects
Nuclear Experiment
Abstract

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

Published
2016
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19. Precision Electron-Beam Polarimetry using Compton Scattering at 1 GeV

Author

Narayan, A., Jones, D., Cornejo, J. C., Dalton, M. M., Deconinck, W., Dutta, D., Gaskell, D., Martin, J. W., Paschke, K. D., Tvaskis, V., Asaturyan, A., Benesch, J., Cates, G., Cavness, B. S., Dillon-Townes, L. A., Hays, G., Ihloff, E., Jones, R., Kowalski, S., Kurchaninov, L., Lee, L., McCreary, A., McDonald, M., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Nelyubin, V., Page, S., Ramsay, W. D., Solvignon, P., Storey, D., Tobias, A., Urban, E., Vidal, C., Wang, P., and Zhamkotchyan, S.

Subjects
Nuclear Experiment, High Energy Physics - Phenomenology, Nuclear Theory, Physics - Accelerator Physics, Physics - Instrumentation and Detectors
Abstract

We report on the highest precision yet achieved in the measurement of the polarization of a low energy, $\mathcal{O}$(1 GeV), electron beam, accomplished using a new polarimeter based on electron-photon scattering, in Hall~C at Jefferson Lab. A number of technical innovations were necessary, including a novel method for precise control of the laser polarization in a cavity and a novel diamond micro-strip detector which was able to capture most of the spectrum of scattered electrons. The data analysis technique exploited track finding, the high granularity of the detector and its large acceptance. The polarization of the $180~\mu$A, $1.16$~GeV electron beam was measured with a statistical precision of $<$~1\% per hour and a systematic uncertainty of 0.59\%. This exceeds the level of precision required by the \qweak experiment, a measurement of the vector weak charge of the proton. Proposed future low-energy experiments require polarization uncertainty $<$~0.4\%, and this result represents an important demonstration of that possibility. This measurement is also the first use of diamond detectors for particle tracking in an experiment., Comment: 9 pages, 7 figures, published in PRX

Published
2015
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20. Double Spin Asymmetries of Inclusive Hadron Electroproductions from a Transversely Polarized $^3\rm{He}$ Target

Author

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

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

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

Published
2015
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21. The Q_weak Experimental Apparatus

Author

Qweak Collaboration, Allison, T., Anderson, M., Androic, D., Armstrong, D. S., Asaturyan, A., Averett, T. D., Averill, R., Balewski, J., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Bessuille, J., Birchall, J., Bonnell, E., Bowman, J., Brindza, P., Brown, D. B., Carlini, R. D., Cates, G. D., Cavness, B., Clark, G., Cornejo, J. C., Dusa, S. Covrig, Dalton, M. M., Davis, C. A., Dean, D. C., Deconinck, W., Diefenbach, J., Dow, K., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Echols, J. R., Elaasar, M., Falk, W. R., Finelli, K. D., Finn, J. M., Gaskell, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hansknecht, J., Harrison, D. J., Henderson, E., Hoskins, J. R., Ihloff, E., Johnston, K., Jones, D., Jones, M., Jones, R., Kargiantoulakis, M., Kelsey, J., Khan, N., King, P. M., Korkmaz, E., Kowalski, S., Kubera, A., Leacock, J., Leckey, J. P., Lee, A. R., Lee, J. H., Lee, L., Liang, Y., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McCreary, A., McDonald, M. H., McHugh, M. J., Medeiros, P., Meekins, D., Mei, J., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Musson, J., Mesick, K. E., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuruzzaman, van Oers, W. T. H., Opper, A. K., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Poelker, M., Rajotte, J. F., Ramsay, W. D., Roberts, W. R., Roche, J., Rose, P. W., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Sobczynski, S., Solvignon, P., Spayde, D. T., Stokes, B., Storey, D. W., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Urban, E., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Zhamkochyan, S., and Zielinski, R. B.

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

The Jefferson Lab Q_weak experiment determined the weak charge of the proton by measuring the parity-violating elastic scattering asymmetry of longitudinally polarized electrons from an unpolarized liquid hydrogen target at small momentum transfer. A custom apparatus was designed for this experiment to meet the technical challenges presented by the smallest and most precise ${\vec{e}}$p asymmetry ever measured. Technical milestones were achieved at Jefferson Lab in target power, beam current, beam helicity reversal rate, polarimetry, detected rates, and control of helicity-correlated beam properties. The experiment employed 180 microA of 89% longitudinally polarized electrons whose helicity was reversed 960 times per second. The electrons were accelerated to 1.16 GeV and directed to a beamline with extensive instrumentation to measure helicity-correlated beam properties that can induce false asymmetries. Moller and Compton polarimetry were used to measure the electron beam polarization to better than 1%. The electron beam was incident on a 34.4 cm liquid hydrogen target. After passing through a triple collimator system, scattered electrons between 5.8 degrees and 11.6 degrees were bent in the toroidal magnetic field of a resistive copper-coil magnet. The electrons inside this acceptance were focused onto eight fused silica Cerenkov detectors arrayed symmetrically around the beam axis. A total scattered electron rate of about 7 GHz was incident on the detector array. The detectors were read out in integrating mode by custom-built low-noise pre-amplifiers and 18-bit sampling ADC modules. The momentum transfer Q^2 = 0.025 GeV^2 was determined using dedicated low-current (~100 pA) measurements with a set of drift chambers before (and a set of drift chambers and trigger scintillation counters after) the toroidal magnet., Comment: 48 pages, 36 figures. Accepted by Nuclear Instruments and Methods A

Published
2014

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

Author

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

Subjects
Nuclear Experiment
Abstract

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

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

Author

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

Subjects
Nuclear Experiment
Abstract

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

Published
2013
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24. Early Results from the Qweak Experiment

Author

Androic, D., Armstrong, D. S., Asaturyan, A., Averett, T., Balewski, J., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cates, G. D., Cornejo, J. C., Covrig, S., Dalton, M. M., Davis, C. A., Deconinck, W., Diefenbach, J., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gaskel, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Johnston, K., Jones, D., Jones, M., Jones, R., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J., McHugh, M. J., Meekins, D., Mei, J., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Myers, K. E., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuruzzaman, van Oers, W. T. H, Opper, A. K., Page, S. A., Pan, J., Paschke, K., Phillips, S. K., Pitt, M. L., Poelker, M., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Young, R. D., and Zhamkochyan, S.

Subjects
Nuclear Experiment
Abstract

A subset of results from the recently completed Jefferson Lab Qweak experiment are reported. This experiment, sensitive to physics beyond the Standard Model, exploits the small parity-violating asymmetry in elastic ep scattering to provide the first determination of the protons weak charge Qweak(p). The experiment employed a 180 uA longitudinally polarized 1.16 GeV electron beam on a 35 cm long liquid hydrogen target. Scattered electrons corresponding to Q2 of 0.025 GeV2 were detected in eight Cerenkov detectors arrayed symmetrically around the beam axis. The goals of the experiment were to provide a measure of Qweak(p) to 4.2 percent (combined statistical and systematic error), which implies a measure of sin2(thetaw) at the level of 0.3 percent, and to help constrain the vector weak quark charges C1u and C1d. The experimental method is described, with particular focus on the challenges associated with the worlds highest power LH2 target. The new constraints on C1u and C1d provided by the subset of the experiments data analyzed to date will also be shown, together with the extracted weak charge of the neutron., Comment: 8 pages, 4 figures, INPC2013

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

Author

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

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

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

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

Author

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

Subjects
Nuclear Experiment
Abstract

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

Published
2013
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27. First Determination of the Weak Charge of the Proton

Author

Qweak Collaboration, Androic, D., Armstrong, D. S., Asaturyan, A., Averett, T., Balewski, J., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cates, G. D., Cornejo, J. C., Covrig, S., Dalton, M. M., Davis, C. A., Deconinck, W., Diefenbach, J., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gaskell, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Johnston, K., Jones, D., Jones, M., Jones, R., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mei, J., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Myers, K. E., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuruzzaman, van Oers, W. T. H, Opper, A. K., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Poelker, M., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Young, R. D., and Zhamkochyan, S.

Subjects
Nuclear Experiment
Abstract

The Qweak experiment has measured the parity-violating asymmetry in polarized e-p elastic scattering at Q^2 = 0.025(GeV/c)^2, employing 145 microamps of 89% longitudinally polarized electrons on a 34.4cm long liquid hydrogen target at Jefferson Lab. The results of the experiment's commissioning run are reported here, constituting approximately 4% of the data collected in the experiment. From these initial results the measured asymmetry is Aep = -279 +- 35 (statistics) +- 31 (systematics) ppb, which is the smallest and most precise asymmetry ever measured in polarized e-p scattering. The small Q^2 of this experiment has made possible the first determination of the weak charge of the proton, QpW, by incorporating earlier parity-violating electron scattering (PVES) data at higher Q^2 to constrain hadronic corrections. The value of QpW obtained in this way is QpW(PVES) = 0.064 +- 0.012, in good agreement with the Standard Model prediction of QpW(SM) = 0.0710 +- 0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES+APV analysis reveals the neutron's weak charge to be QnW(PVES+APV) = -0.975 +- 0.010., Comment: 7 pages, 3 figures

Published
2013
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28. Polarization components in $\pi^{0}$ photoproduction at photon energies up to 5.6 GeV

Author

Luo, W., Brash, E. J., Gilman, R., Jones, M. K., Meziane, M., Pentchev, L., Perdrisat, C. F., Puckett, A. J. R., Punjabi, V., Wesselmann, F. R., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Ates, O., Baghdasaryan, H., Benmokhtar, F., Bertozzi, W., Bimbot, L., Bosted, P., Boeglin, W., Butuceanu, C., Carter, P., Chernenko, S., Christy, M. 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., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Kang, H., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Markowitz, P., 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., Nuruzzaman, Nedev, S., Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P. E., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Strakovsky, I. I., Subedi, R., Suleiman, R., Tomasi-Gustafsson, E., Vasiliev, A., Veilleux, M., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L.

Subjects
Nuclear Experiment
Abstract

We present new data for the polarization observables of the final state proton in the $^{1}H(\vec{\gamma},\vec{p})\pi^{0}$ reaction. These data can be used to test predictions based on hadron helicity conservation (HHC) and perturbative QCD (pQCD). These data have both small statistical and systematic uncertainties, and were obtained with beam energies between 1.8 and 5.6 GeV and for $\pi^{0}$ scattering angles larger than 75$^{\circ}$ in center-of-mass (c.m.) frame. The data extend the polarization measurements data base for neutral pion photoproduction up to $E_{\gamma}=5.6 GeV$. The results show non-zero induced polarization above the resonance region. The polarization transfer components vary rapidly with the photon energy and $\pi^{0}$ scattering angle in c.m. frame. This indicates that HHC does not hold and that the pQCD limit is still not reached in the energy regime of this experiment., Comment: 6 pages and 2 figures

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

Author

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

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

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

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

Author

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

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

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

Published
2011
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31. Search for effects beyond the Born approximation in polarization transfer observables in $\vec{e}p$ elastic scattering

Author

Meziane, M., Brash, E. J., Gilman, R., Jones, M. K., Luo, W., Pentchev, L., Perdrisat, C. F., Puckett, A. J. R., Punjabi, V., Wesselmann, F. R., Ahmidouch, A., Albayrak, I., Aniol, K. A., Arrington, J., Asaturyan, A., Ates, O., 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., Goncharenko, Y., Hafidi, K., Hamilton, D., Higinbotham, D. W., Hinton, W., Horn, T., Hu, B., Huang, J., Huber, G. M., Jensen, E., Kang, H., Keppel, C., Khandaker, M., King, P., Kirillov, D., Kohl, M., Kravtsov, V., Kumbartzki, G., Li, Y., Mamyan, V., Margaziotis, D. J., Markowitz, P., 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., Nuruzzaman, Nedev, S., Piasetzky, E., Pierce, W., Piskunov, N. M., Prok, Y., Ransome, R. D., Razin, D. S., Reimer, P. E., Reinhold, J., Rondon, O., Shabestari, M., Shahinyan, A., Shestermanov, K., Sirca, S., Sitnik, I., Smykov, L., Smith, G., Solovyev, L., Solvignon, P., Subedi, R., Suleiman, R., Tomasi-Gustafsson, E., Vasiliev, A., Vanderhaeghen, M., Veilleux, M., Wojtsekhowski, B. B., Wood, S., Ye, Z., Zanevsky, Y., Zhang, X., Zhang, Y., Zheng, X., and Zhu, L.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, $G_{E}/G_{M}$, obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange (TPEX) contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic $H(\vec{e},e'\vec{p})$ reaction for three different beam energies at a fixed squared momentum transfer $Q^2 = 2.5$ GeV$^2$, spanning a wide range of the virtual photon polarization parameter, $\epsilon$. From these measured polarization observables, we have obtained separately the ratio $R$, which equals $\mu_p G_{E}/G_{M}$ in the Born approximation, and the longitudinal polarization transfer component $P_\ell$, with statistical and systematic uncertainties of $\Delta R \approx \pm 0.01 \mbox{(stat)} \pm 0.013 \mbox{(syst)}$ and $\Delta P_\ell/P^{Born}_{\ell} \approx \pm 0.006 \mbox{(stat)}\pm 0.01 \mbox{(syst)}$. The ratio $R$ is found to be independent of $\epsilon$ at the 1.5% level, while the $\epsilon$ dependence of $P_\ell$ shows an enhancement of $(2.3 \pm 0.6) %$ relative to the Born approximation at large $\epsilon$.

Published
2010
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32. Recoil Polarization Measurements of the Proton Electromagnetic Form Factor Ratio to Q^2 = 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., 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, Nuclear Theory
Abstract

Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5 GeV2. By extending the range of Q2 for which GEp is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the non-perturbative regime.

Published
2010
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33. The tracking analysis in the Q-weak experiment

Author

Pan, J., Androic, D., Armstrong, D. S., Asaturyan, A., Averett, T., Balewski, J., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cates, G. D., Cornejo, J. C., Covrig, S., Dalton, M. M., Davis, C. A., Deconinck, W., Diefenbach, J., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gaskell, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Johnston, K., Jones, D., Jones, M., Jones, R., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mei, J., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Myers, K. E., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuruzzaman, van Oers, W. T. H, Opper, A. K., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Poelker, M., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Young, R. D., and Zhamkochyan, S.

Published
2016
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34. Form Factors and Two-Photon Exchange in High-Energy Elastic Electron-Proton Scattering

Author

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

Published
2022
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35. 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
General Physics and Astronomy, FOS: Physical sciences, Nuclear Experiment (nucl-ex), single spin asymmetry, elastic electron scattering, 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
2022

36. 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, John, 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, M. E., Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, J. C., 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, V. M., Gu, C, Hague, T, Hamad, G, Hamilton, David, Hamilton, K., Hansen, O, Hauenstein, F, Henry, W, Higinbotham, D. W., Holmstrom, T, Horn, T, Huang, Y, Huber, G. M., Hyde, C. E., 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, Rachel, Muñoz Camacho, C, 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, Zhu, P, and Jefferson Lab Hall A Collaboration

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

37. Determination of the ^{27}Al Neutron Distribution Radius from a Parity-Violating Electron Scattering Measurement

Author

Androić, Darko, Armstrong, D. S., Bartlett, K., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cornejo, J. C., Covrig Dusa, S., Dalton, M. M., Davis, C. A., Deconinck, W., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gal, C., Gaskell, D., Gericke, M. T. W., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Jones, D. C., Jones, M. K., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mesick, K. E., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuruzzaman, van Oers, W. T. H., Owen, V. F., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Radloff, R. W., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Ševa, Tomislav, Shabestari, M. H., Silwal, R., Šimičević, Neven, Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Zang, P., Zhamkochyan, S., Christy, M. E., Horowitz, C. J., Fattoyev, F. J., and Lin, Z.

Subjects
parity vialation, elastic electron scattering asimmetry, neuton skin thickness
Abstract

We report the first measurement of the parity- violating elastic electron scattering asymmetry on 27Al. The 27Al elastic asymmetry is A_PV = 2.16 +- 0.11 (stat) +- 0.16 (syst) ppm, and was measured at =0.02357 +- 0.0001 GeV^2, = 7.61 +- 0.02 degrees, and = 1.157 GeV with the Qweak apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the 27Al neutron radius R_n = 2.89 +- 0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_n-R_p = -0.04 +- 0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the 27Al weak radius R_w = 3.00 +- 0.15 fm, and the weak skin thickness R_wk - R_ch = -0.04 +- 0.15 fm. The weak form factor at this Q^2 is F_wk = 0.39 +- 0.04.

Published
2021

38. The ${Q^{p}_{\rm Weak}}$ experiment: A search for physics beyond the standard model via a measurement of the proton’s weak charge

Author

Androic, D., Armstrong, D. S., Asaturyan, A., Averett, T., Balewski, J., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cornejo, J. C., Covrig, S., Dalton, M. M., Davis, C. A., Deconinck, W., Diefenbach, J., Dow, K., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gaskell, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Johnston, K., Jones, D., Jones, M., Jones, R., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J., McHugh, M., Meekins, D., Mei, J., Michaels, R., Micherdzinska, A., Myers, K. E., Mkrtchyan, A., Mkrtchyan, H., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuruzzaman, N., van Oers, W. T. H, Opper, A. K., Page, S. A., Pan, J., Paschke, K., Phillips, S. K., Pitt, M. L., Poelker, M., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Young, R. D., Zhamkochyan, S., and Zou, D.

Published
2013
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39. Deep Exclusive Electroproduction of π0 at High Q2 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., Zhu, P., Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Jefferson Lab Hall A

Subjects
[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], momentum transfer dependence, helicity, High Energy Physics - Experiment, pi: distribution amplitude, generalized parton distribution: transversity, kinematics, pi0: electroproduction, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], quark: valence, polarization: transverse, High Energy Physics::Experiment, p: structure function, Nuclear Experiment, experimental results, photon: virtual, Jefferson Lab
Abstract

International audience; We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of xB (0.36, 0.48, and 0.60) and Q2 (3.1 to 8.4 GeV2) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσT/dt+εdσL/dt, dσTT/dt, dσLT/dt, and dσLT′/dt are extracted as a function of the proton momentum transfer t-tmin. 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

40. Parity-violating inelastic electron-proton scattering at low Q2 above the resonance region

Author

Androić, D., Armstrong, D. S., Asaturyan, A., Bartlett, K., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cornejo, J. C., Covrig Dusa, S., Dalton, M. M., Davis, C. A., Deconinck, W., Dowd, J. F., Dunne, J. A., Dutta, D., Duvall, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Gal, C., Gaskell, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Jones, D., Jones, M. K., Jones, R. T., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J. P., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mesick, K. E., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Narayan, A., Ndukum, L. Z., Nelyubin, V., van Oers, W. T. H., Owen, V. F., Page, S. A., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Radloff, R. W., Ramsay, W. D., Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H., Silwal, R., Simicevic, N., Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Suleiman, R., Tadevosyan, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Zang, P., and Qweak Collaboration

Subjects
three-body breakup, reaction cross section, helium-3, Photon, media_common.quotation_subject, Nuclear Theory, FOS: Physical sciences, Electron, Inelastic scattering, 01 natural sciences, Asymmetry, Nuclear physics, High Energy Physics - Phenomenology (hep-ph), Proton scattering, 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, media_common, Physics, Elastic scattering, 010308 nuclear & particles physics, Structure function, Parity (physics), NATURAL SCIENCES. Physics, PRIRODNE ZNANOSTI. Fizika, High Energy Physics - Phenomenology, High Energy Physics::Experiment
Abstract

We report the measurement of the parity-violating asymmetry for the inelastic scattering of electrons from the proton, at $Q^2 = 0.082$ GeV$^2$ and $ W = 2.23$ GeV, above the resonance region. The result $A_{\rm Inel} = - 13.5 \pm 2.0 ({\rm stat}) \pm 3.9 ({\rm syst})$~ppm agrees with theoretical calculations, and helps to validate the modeling of the $\gamma Z$ interference structure functions $F_1^{\gamma Z}$ and $F_2^{\gamma Z}$ used in those calculations, which are also used for determination of the two-boson exchange box diagram ($\Box_{\gamma Z}$) contribution to parity-violating elastic scattering measurements. A positive parity-violating asymmetry for inclusive $\pi^-$ production was observed, as well as positive beam-normal single-spin asymmetry for scattered electrons and a negative beam-normal single-spin asymmetry for inclusive $\pi^-$ production., Comment: 18 pages, 9 figures, version accepted in Physical Review C

Published
2020

41. The ${Q^{p}_{\rm Weak}}$ experiment

Author

Androic, D., primary, Armstrong, D. S., additional, Asaturyan, A., additional, Averett, T., additional, Balewski, J., additional, Beaufait, J., additional, Beminiwattha, R. S., additional, Benesch, J., additional, Benmokhtar, F., additional, Birchall, J., additional, Carlini, R. D., additional, Cornejo, J. C., additional, Covrig, S., additional, Dalton, M. M., additional, Davis, C. A., additional, Deconinck, W., additional, Diefenbach, J., additional, Dow, K., additional, Dowd, J. F., additional, Dunne, J. A., additional, Dutta, D., additional, Duvall, W. S., additional, Elaasar, M., additional, Falk, W. R., additional, Finn, J. M., additional, Forest, T., additional, Gaskell, D., additional, Gericke, M. T. W., additional, Grames, J., additional, Gray, V. M., additional, Grimm, K., additional, Guo, F., additional, Hoskins, J. R., additional, Johnston, K., additional, Jones, D., additional, Jones, M., additional, Jones, R., additional, Kargiantoulakis, M., additional, King, P. M., additional, Korkmaz, E., additional, Kowalski, S., additional, Leacock, J., additional, Leckey, J., additional, Lee, A. R., additional, Lee, J. H., additional, Lee, L., additional, MacEwan, S., additional, Mack, D., additional, Magee, J. A., additional, Mahurin, R., additional, Mammei, J., additional, Martin, J., additional, McHugh, M., additional, Meekins, D., additional, Mei, J., additional, Michaels, R., additional, Micherdzinska, A., additional, Myers, K. E., additional, Mkrtchyan, A., additional, Mkrtchyan, H., additional, Narayan, A., additional, Ndukum, L. Z., additional, Nelyubin, V., additional, Nuruzzaman, N., additional, van Oers, W. T. H, additional, Opper, A. K., additional, Page, S. A., additional, Pan, J., additional, Paschke, K., additional, Phillips, S. K., additional, Pitt, M. L., additional, Poelker, M., additional, Rajotte, J. F., additional, Ramsay, W. D., additional, Roche, J., additional, Sawatzky, B., additional, Seva, T., additional, Shabestari, M. H., additional, Silwal, R., additional, Simicevic, N., additional, Smith, G., additional, Solvignon, P., additional, Spayde, D. T., additional, Subedi, A., additional, Subedi, R., additional, Suleiman, R., additional, Tadevosyan, V., additional, Tobias, W. A., additional, Tvaskis, V., additional, Waidyawansa, B., additional, Wang, P., additional, Wells, S. P., additional, Wood, S. A., additional, Yang, S., additional, Young, R. D., additional, Zhamkochyan, S., additional, and Zou, D., additional

Published
2013
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42. Measurement of the 3He Spin-Structure Functions and of Neutron (3He) Spin-Dependent Sum Rules at 0.035

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
High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, Nuclear Experiment (nucl-ex)
Abstract

The spin-structure functions $g_1$ and $g_2$, and the spin-dependent partial cross-section $��_\mathrm{TT}$ have been extracted from the polarized cross-sections differences, $����_{\parallel}\hspace{-0.06cm}\left(��,Q^{2}\right)$ and $����_{\perp}\hspace{-0.06cm}\left(��,Q^{2}\right)$ 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 $\overline{��_1}\hspace{-0.06cm}\left(Q^{2}\right)$, $��_2\hspace{-0.06cm}\left(Q^{2}\right)$ 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 $��$ degree of freedom for spin observables., 7 pages, 5 figures, 3 tables. Version published in Phys. Lett. B

Published
2019
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43. Polarization transfer observables in elastic electron-proton scattering at Q2=2.5, 5.2, 6.8, and 8.5 GeV2

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, M. 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., Širca, 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.

Abstract

Purpose: The GEp-III and GEp-2γ experiments were carried out in Jefferson Laboratory’s (JLab’s) Hall C from\ud 2007 to 2008, to extend the knowledge of Gp\ud E/Gp\ud M to the highest practically achievable Q2 given the maximum\ud beam energy of 6 GeV and to search for effects beyond the Born approximation in polarization transfer observables\ud of elastic ep scattering. This article provides an expanded description of the common experimental apparatus and\ud data analysis procedures, and reports the results of a final reanalysis of the data from both experiments, including\ud the previously unpublished results of the full-acceptance dataset of the GEp-2γ experiment.\ud Methods: Polarization transfer observables in elastic ep → ep scattering were measured at central Q2 values\ud of 2.5, 5.2, 6.8, and 8.54 GeV2\ud . At Q2 = 2.5 GeV2\ud , data were obtained for central values of the virtual photon\ud polarization parameter of 0.149, 0.632, and 0.783. The Hall C High Momentum Spectrometer detected and\ud measured the polarization of protons recoiling elastically from collisions of JLab’s polarized electron beam\ud with a liquid hydrogen target. A large-acceptance electromagnetic calorimeter detected the elastically scattered\ud electrons in coincidence to suppress inelastic backgrounds.\ud Results: The final GEp-III data are largely unchanged relative to the originally published results. The statistical\ud uncertainties of the final GEp-2γ data are significantly reduced at = 0.632 and 0.783 relative to the original\ud publication.\ud Conclusions: The final GEp-III results show that the decrease with Q2 of Gp\ud E/Gp\ud M continues to Q2 = 8.5 GeV2, but at a slowing rate relative to the approximately linear decrease observed in earlier Hall A measurements. At\ud Q2 = 8.5 GeV2\ud , Gp\ud E/Gp\ud M remains positive but is consistent with zero. At Q2 = 2.5 GeV2\ud , Gp\ud E/Gp\ud M derived from\ud the polarization component ratio R ∝ Pt/P shows no statistically significant dependence, as expected in the\ud Born approximation. On the other hand, the ratio Pl/P Born\ud l of the longitudinal polarization transfer component\ud to its Born value shows an enhancement of roughly 1.7% at = 0.783 relative to = 0.149, with ≈ 2.2σ\ud significance based on the total uncertainty, implying a similar effect in the transverse component Pt that cancels\ud in the ratio R.

Published
2017

44. First Direct Measurement of the Proton’s Weak Charge

Author

Androić, Darko, Armstrong, D. S., Asaturyan, A., Averett, T., Balewski, J., Bartlett, K., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cates, G. D., Cornejo, J. C., Covrig, S., Dalton, M. M., Davis, C. A., Deconinck, W., Diefenbach, J., Dowd, J. F., Dunne, J. A., Dutta, D., Duvalla, W. S., Elaasar, M., Falk, W. R., Finn, J. M., Forest, T., Gal, C., Gaskell, D., Gericke, M. T. W., Grames, J., Gray, V. M., Grimm, K., Guo, F., Hoskins, J. R., Johnston, K., Jones, D., Jones, M., Jones, R., Kargiantoulakis, M., King, P. M., Korkmaz, E., Kowalski, S., Leacock, J., Leckey, J., Lee, A. R., Lee, J. H., Lee, L., MacEwan, S., Mack, D., Magee, J. A., Mahurin, R., Mammei, J., Martin, J. W., McHugh, M. J., Meekins, D., Mei, J., Michaels, R., Micherdzinska, A., Mkrtchyan, A., Mkrtchyan, H., Morgan, N., Myers, K. E., Narayan, A., Ndukum, L. Z., Nelyubin, V., Nuhait, H., Nuruzzaman, W.T.H van Oers, Page, S. A., Opper, A. K., Pan, J., Paschke, K. D., Phillips, S. K., Pitt, M. L., Poelker, M., Rajotte, J. F., Ramsay, W. D., Roche, J., Sawatzky, B., Ševa, Tomislav, Shabestari, M. H., Silwal, R., Šimičević, Neven, Smith, G. R., Solvignon, P., Spayde, D. T., Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A., Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P., Wood, S. A., Yang, S., Young, R. D., Zang, P., and Zhamkochyan, S.

Subjects
PRIRODNE ZNANOSTI. Fizika, q-weak experiment, Nuclear Experiment, NATURAL SCIENCES. Physics
Abstract

The Qweak experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q2 = 0.025 (GeV/c)2. The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well as the method of extracting the weak charge of the proton. The results from a small subset of the data, that has been published, will also be presented. Furthermore an update will be given of the current status of the data analysis.

Published
2017

46. First measurement of unpolarized semi-inclusive deep-inelastic scattering cross sections from a ³He target

Author

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

Abstract

United States. Department of Energy (contract DE-AC05-06OR23177), United States. Department of Energy (contract DE-FG02-03ER41231)

Published
2017

48. Precision Electron-Beam Polarimetry at 1 GeV Using Diamond Microstrip Detectors

Author

Narayan, A., primary, Jones, D., additional, Cornejo, J. C., additional, Dalton, M. M., additional, Deconinck, W., additional, Dutta, D., additional, Gaskell, D., additional, Martin, J. W., additional, Paschke, K. D., additional, Tvaskis, V., additional, Asaturyan, A., additional, Benesch, J., additional, Cates, G., additional, Cavness, B. S., additional, Dillon-Townes, L. A., additional, Hays, G., additional, Ihloff, E., additional, Jones, R., additional, King, P. M., additional, Kowalski, S., additional, Kurchaninov, L., additional, Lee, L., additional, McCreary, A., additional, McDonald, M., additional, Micherdzinska, A., additional, Mkrtchyan, A., additional, Mkrtchyan, H., additional, Nelyubin, V., additional, Page, S., additional, Ramsay, W. D., additional, Solvignon, P., additional, Storey, D., additional, Tobias, A., additional, Urban, E., additional, Vidal, C., additional, Waidyawansa, B., additional, Wang, P., additional, and Zhamkotchyan, S., additional

Published
2016
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49. Qweak: First Direct Measurement of the Proton's Weak Charge.

Author

Androic, D., Armstrong, D. S., Asaturyan, A., Averett, T., Balewski, J., Bartlett, K., Beaufait, J., Beminiwattha, R. S., Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D., Cates, G. D., Cornejo, J. C., Covrig, S., Dalton, M. M., Davis, C. A., Deconinck, W., Diefenbach, J., and Dowd, J. F.

Subjects
PROTONS, ELASTIC scattering, MOMENTUM transfer, ELECTRON beams, LIQUID hydrogen
Abstract

The article presents an overview of the Qweak experiment which aimed to determine the weak charge of the proton QpW and discusses its results. Topics mentioned include measurement of the parity-violating asymmetry, the construction of the Qweak apparatus in Hall C at the Thomas Jefferson National Accelerator Facility, and the Qweak's liquid nitrogen target.

Published
2017
Full Text
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50. The Q[superscript p][subscript Weak] experiment

Author

Androic, D., Armstrong, D. S, Asaturyan, A., Averett, T., Beaufait, J., Beminiwattha, R. S, Benesch, J., Benmokhtar, F., Birchall, J., Carlini, R. D, Cornejo, J. C, Covrig, S., Dalton, M. M, Davis, C. A, Deconinck, W., Diefenbach, J., Dowd, J. F, Dunne, J. A, Dutta, D., Duvall, W. S, Elaasar, M., Falk, W. R, Finn, J. M, Forest, T., Gaskell, D., Gericke, M. T W, Grames, J., Gray, V. M, Grimm, K., Hoskins, J. R, Johnston, K., Jones, D., Jones, M., Jones, R., Kargiantoulakis, M., King, P. M, Korkmaz, E., Leacock, J., Leckey, J., Lee, A. R, Lee, J. H, Lee, L., MacEwan, S., Mack, D., Magee, J. A, Mahurin, R., Mammei, J., Martin, J., McHugh, M., Meekins, D., Mei, J., Michaels, R., Micherdzinska, A., Myers, K. E, Mkrtchyan, A., Mkrtchyan, H., Narayan, A., Ndukum, L. Z, Nelyubin, V., Nuruzzaman, N., van Oers, W. T H, Opper, A. K, Page, S. A, Pan, J., Paschke, K., Phillips, S. K, Pitt, M. L, Poelker, M., Ramsay, W. D, Roche, J., Sawatzky, B., Seva, T., Shabestari, M. H, Silwal, R., Simicevic, N., Smith, G., Solvignon, P., Spayde, D. T, Subedi, A., Subedi, R., Suleiman, R., Tadevosyan, V., Tobias, W. A, Tvaskis, V., Waidyawansa, B., Wang, P., Wells, S. P, Wood, S. A, Yang, S., Young, R. D, Zhamkochyan, S., Balewski, Jan T., Dow, Karen Ann, Guo, Fang, Kowalski, Stanley B, Rajotte, Jean-Francois, Zou, David, Massachusetts Institute of Technology. Department of Physics, Massachusetts Institute of Technology. Laboratory for Nuclear Science, Balewski, Jan T., Dow, Karen Ann, Guo, Fang, Kowalski, Stanley B, Rajotte, Jean-Francois, and Zou, David

Abstract

In May 2012, the Q[superscript p][subscript Weak] collaboration completed a two year measurement program to determine the weak charge of the proton Q[superscript p][subscript Weak] = ( 1 - 4sin [superscript 2] θ[subscript W] at the Thomas Jefferson National Accelerator Facility (TJNAF). The experiment was designed to produce a 4.0 % measurement of the weak charge, via a 2.5 % measurement of the parity violating asymmetry in the number of elastically scattered 1.165 GeV electrons from protons, at forward angles. At the proposed precision, the experiment would produce a 0.3 % measurement of the weak mixing angle at a momentum transfer of Q[superscript 2] = 0.026 GeV[superscript 2], making it the most precise stand alone measurement of the weak mixing angle at low momentum transfer. In combination with other parity measurements, Q[superscript p][subscript Weak] will also provide a high precision determination of the weak charges of the up and down quarks. At the proposed precision, a significant deviation from the Standard Model prediction could be a signal of new physics at mass scales up to ≃ 6 TeV, whereas agreement would place new and significant constraints on possible Standard Model extensions at mass scales up to ≃ 2 TeV. This paper provides an overview of the physics and the experiment, as well as a brief look at some preliminary diagnostic and analysis data.

Published
2013

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