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3,524 results on '"Hansen O."'

1. Pion electroproduction measurements in the nucleon resonance region

Author: Li, R., Sparveris, N., Atac, H., Jones, M. K., Paolone, M., Akbar, Z., Ali, M., Gayoso, C. Ayerbe, Berdnikov, V., Biswas, D., Boer, M., Camsonne, A., Chen, J. -P., Diefenthaler, M., Duran, B., Dutta, D., Gaskell, D., Hansen, O., Hauenstein, F., Heinrich, N., Henry, W., Horn, T., Huber, G. M., Jia, S., Joosten, S., Karki, A., Kay, S. J. D., Kumar, V., Li, X., Li, W. B., Liyanage, A. H., Mack, D., Malace, S., Markowitz, P., McCaughan, M., Meziani, Z. -E., Mkrtchyan, H., Morean, C., Muhoza, M., Narayan, A., Pasquini, B., Rehfuss, M., Sawatzky, B., Smith, G. R., Smith, A., Trotta, R., Yero, C., Zheng, X., and Zhou, J.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: We report new pion electroproduction measurements in the $\Delta(1232)$ resonance, utilizing the SHMS - HMS magnetic spectrometers of Hall C at Jefferson Lab. The data focus on a region that exhibits a strong and rapidly changing interplay of the mesonic cloud and quark-gluon dynamics in the nucleon. The results are in reasonable agreement with models that employ pion cloud effects and chiral effective field theory calculations, but at the same time they suggest that an improvement is required to the theoretical calculations and provide valuable input that will allow their refinements. The data illustrate the potential of the magnetic spectrometers setup in Hall C towards the study the $\Delta(1232)$ resonance. These first reported results will be followed by a series of measurements in Hall C, that will expand the studies of the $\Delta(1232)$ resonance offering a high precision insight within a wide kinematic range from low to high momentum transfers.
Published: 2024
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2. Photosynthesis

Author: Calvin, M, Anderson, J M, Bassham, J A, Blass, U, Holm-Hansen, O, Moses, V, Pon, N G, Sogo, P B, and Tollin, G
Published: 2024

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

Author: Okuyama, K., Itabashi, K., Nagao, S., Nakamura, S. N., Suzuki, K. N., Gogami, T., Pandey, B., Tang, L., Bydžovský, P., Skoupil, D., Mart, T., Abrams, D., Akiyama, T., Androic, D., Aniol, K., Gayoso, C. Ayerbe, Bane, J., Barcus, S., Barrow, J., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Camsonne, A., Castellanos, J., Chen, J-P., Chen, J., Covrig, S., Chrisman, D., Cruz-Torres, R., Das, R., Fuchey, E., Gnanvo, K., Garibaldi, F., Gautam, T., Gomez, J., Gueye, P., Hague, T. J., Hansen, O., Henry, W., Hauenstein, F., Higinbotham, D. W., Hyde, C. E., Kaneta, M., Keppel, C., Kutz, T., Lashley-Colthirst, N., Li, S., Liu, H., Mammei, J., Markowitz, P., McClellan, R. E., Meddi, F., Meekins, D., Michaels, R., Mihovilovič, M., Moyer, A., Nguyen, D., Nycz, M., Owen, V., Palatchi, C., Park, S., Petkovic, T., Premathilake, S., Reimer, P. E., Reinhold, J., Riordan, S., Rodriguez, V., Samanta, C., Santiesteban, S. N., Sawatzky, B., Širca, S., Slifer, K., Su, T., Tian, Y., Toyama, Y., Uehara, K., Urciuoli, G. M., Votaw, D., Williamson, J., Wojtsekhowski, B., Wood, S. A., Yale, B., Ye, Z., Zhang, J., and Zheng, X.
Subjects: Nuclear Experiment
Abstract: In 2018, the E12-17-003 experiment was conducted at the Thomas Jefferson National Accelerator Facility (JLab) to explore the possible existence of an nnLambda state in the reconstructed missing mass distribution from a tritium gas target [K. N. Suzuki et al., Prog. Theor. Exp. Phys. 2022, 013D01 (2022), B. Pandey et al., Phys. Rev. C 105, L051001 (2022)]. As part of this investigation, data was also collected using a gaseous hydrogen target, not only for a precise absolute mass scale calibration but also for the study of Lambda/Sigma^0 electroproduction. This dataset was acquired at Q^2~0.5 (GeV/c)^2, W=2.14 GeV, and theta_{gamma K}^{c.m.}~8 deg. It covers forward angles where photoproduction data is scarce and a low-Q^2 region that is of interest for hypernuclear experiments. On the other hand, this kinematic region is at a slightly higher Q^2 than previous hypernuclear experiments, thus providing crucial information for understanding the Q^2 dependence of the differential cross sections for Lambda/Sigma^0 hyperon electroproduction. This paper reports on the Q^2 dependence of the differential cross section for the e + p -> e' + K^+ + Lambda/Sigma^0 reaction in the 0.2-0.8 (GeV/c)^2, and provides comparisons with the currently available theoretical models., Comment: 11 pages, 15 figures
Published: 2024

4. Cross-section measurement of virtual photoproduction of iso-triplet three-body hypernucleus, Λnn

Author: Gogami T., Suzuki K. N., Pandey B., Itabashi K., Nagao S., Okuyama K., Nakamura S. N., Tang L., Abrams D., Akiyama T., Androic D., Aniol K., Ayerbe Gayoso C., Bane J., Barcus S., Barrow J., Bellini V., Bhatt H., Bhetuwal D., Biswas D., Camsonne A., Castellanos J., Chen J-P., Chen J., Covrig S., Chrisman D., Cruz-Torres R., Das R., Fuchey E., Gnanvo K., Garibaldi F., Gautam T., Gomez J., Gueye P., Hague T. J., Hansen O., Henry W., Hauenstein F., Higinbotham D. W., Hyde C. E., Kaneta M., Keppel C., Kutz T., Lashley-Colthirst N., Li S., Liu H., Mammei J., Markowitz P., McClellan R. E., Meddi F., Meekins D., Michaels R., Mihovilovic M., Moyer A., Nguyen D., Nycz M., Owen V., Palatchi C., Park S., Petkovic T., Premathilake S., Reimer P. E., Reinhold J., Riordan S., Rodriguez V., Samanta C., Santiesteban S. N., Sawatzky B., Širca S., Slifer K., Su T., Tian Y., Toyama Y., Uehara K., Urciuoli G. M., Votaw D., Williamson J., Wojtsekhowski B., Wood S. A., Yale B., Ye Z., Zhang J., and Zheng X.
Subjects: Physics, QC1-999
Abstract: Missing-mass spectroscopy with the 3H(e, e′K+) reaction was carried out at Jefferson Lab’s (JLab) Hall A in Oct–Nov, 2018. The differential cross section for the 3H(γ∗, K+)Λnn was deduced at ω = Ee − Ee′ = 2.102 GeV and at the forward K+-scattering angle (0° ≤ θγ∗K ≤ 5°) in the laboratory frame. Given typical predicted energies and decay widths, which are (BΛ, Γ) = (−0.25, 0.8) and (−0.55, 4.7) MeV, the cross sections were found to be 11.2 ± 4.8(stat.)+4.1−2.1(sys.) and 18.1 ± 6.8(stat.)+4.2−2.9(sys.) nb/sr, respectively. The obtained result would impose a constraint for interaction models particularly between Λ and neutron by comparing to theoretical calculations.
Published: 2022
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5. Study of the Λ/Σ0 electroproduction in the low-Q2 region at JLab

Author: Okuyama K., Itabashi K., Nagao S., Nakamura S. N., Suzuki K. N., Gogami T., Pandey B., Tang L., Abrams D., Akiyama T., Androic D., Aniol K., Ayerbe Gayoso C., Bane J., Barcus S., Barrow J., Bellini V., Bhatt H., Bhetuwal D., Biswas D., Camsonne A., Castellanos J., Chen J-P., Chen J., Covrig S., Chrisman D., Cruz-Torres R., Das R., Fuchey E., Gnanvo K., Garibaldi F., Gautam T., Gomez J., Gueye P., Hague T. J., Hansen O., Henry W., Hauenstein F., Higinbotham D. W., Hyde C. E., Kaneta M., Keppel C., Kutz T., Lashley-Colthirst N., Li S., Liu H., Mammei J., Markowitz P., McClellan R. E., Meddi F., Meekins D., Michaels R., Mihovilovic M., Moyer A., Nguyen D., Nycz M., Owen V., Palatchi C., Park S., Petkovic T., Premathilake S., Reimer P. E., Reinhold J., Riordan S., Rodriguez V., Samanta C., Santiesteban S. N., Sawatzky B., Širca S., Slifer K., Su T., Tian Y., Toyama Y., Uehara K., Urciuoli G. M., Votaw D., Williamson J., Wojtsekhowski B., Wood S. A., Yale B., Ye Z., Zhang J., and Zheng X.
Subjects: Physics, QC1-999
Abstract: We performed an experiment using tritium and hydrogen cryogenic gas targets at Thomas Jefferson National Accelerator Facility (JLab) in 2018 (E12-17-003)[1, 2]. In this article, we discuss the Λ/Σ0 hyperon electroproduction from hydrogen target. Elementary Λ/Σ0 hyperon production processes are important not only for an absolute mass scale calibration in our experiment, but also for the study of the electroproduction mechanisms themselves. In this article, we reported the results of the differential cross section for the p(e, e’K+)Λ/Σ0 reaction at Q2 ∼ 0.5 (GeV/c)2.
Published: 2022
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6. Study of Λn FSI with Λ quasi-free productions on the 3H(e, e′K+)X reaction at JLab

Author: Itabashi K., Suzuki K.N., Pandey B., Okuyama K., Gogami T., Nagao S., Nakamura S.N., Tang L., Abrams D., Akiyama T., Androic D., Aniol K., Ayerbe Gayoso C., Bane J., Barcus S., Barrow J., Bellini V., Bhatt H., Bhetuwal D., Biswas D., Camsonne A., Castellanos J., Chen J-P., Chen J., Covrig S., Chrisman D., Cruz-Torres R., Das R., Fuchey E., Gnanvo K., Garibaldi F., Gautam T., Gomez J., Gueye P., Hague T.J., Hansen O., Henry W., Hauenstein F., Higinbotham D.W., Hyde C.E., Kaneta M., Keppel C., Kutz T., Lashley-Colthirst N., Li S., Liu H., Mammei J., Markowitz P., McClellan R. E., Meddi F., Meekins D., Michaels R., Mihovilovic M., Moyer A., Nguyen D., Nycz M., Owen V., Palatchi C., Park S., Petkovic T., Premathilake S., Reimer P.E., Reinhold J., Riordan S., Rodriguez V., Samanta C., Santiesteban S.N., Sawatzky B., Širca S., Slifer K., Su T., Tian Y., Toyama Y., Uehara K., Urciuoli G.M., Votaw D., Williamson J., Wojtsekhowski B., Wood S.A., Yale B., Ye Z., Zhang J., and Zheng X.
Subjects: Physics, QC1-999
Abstract: Abstract. An nnΛ is a neutral baryon system with no charge. The study of the pure Λ-neutron system such as nnΛ gives us information on the Λn interaction. The nnΛ search experiment (E12-17-003) was performed at JLab Hall A in 2018. In this article, the Λn FSI was investigated by a shape analysis of the 3H(e, e′K+)X missing mass spectrum, and a preliminary result for the Λn FSI study is given.
Published: 2022
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7. Measured proton electromagnetic structure deviates from theoretical predictions

Author: Li, R., Sparveris, N., Atac, H., Jones, M. K., Paolone, M., Akbar, Z., Gayoso, C. Ayerbe, Berdnikov, V., Biswas, D., Boer, M., Camsonne, A., Chen, J. -P., Diefenthaler, M., Duran, B., Dutta, D., Gaskell, D., Hansen, O., Hauenstein, F., Heinrich, N., Henry, W., Horn, T., Huber, G. M., Jia, S., Joosten, S., Karki, A., Kay, S. J. D., Kumar, V., Li, X., Li, W. B., Liyanage, A. H., Malace, S., Markowitz, P., McCaughan, M., Meziani, Z. -E., Mkrtchyan, H., Morean, C., Muhoza, M., Narayan, A., Pasquini, B., Rehfuss, M., Sawatzky, B., Smith, G. R., Smith, A., Trotta, R., Yero, C., Zheng, X., and Zhou, J.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton's bound state.A fundamental property of the proton involves the response of the system to an external electromagnetic field. It is characterized by the electromagnetic polarizabilities that describe how easily the charge and magnetization distributions inside the system are distorted by the electromagnetic field. Moreover, the generalized polarizabilities map out the resulting deformation of the densities in a proton subject to an electromagnetic field. They disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents. Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved for two decades. Here we report measurements of the proton's electromagnetic generalized polarizabilities at low four-momentum transfer squared. We show evidence of an anomaly to the behaviour of the proton's electric generalized polarizability that contradicts the predictions of nuclear theory and derive its signature in the spatial distribution of the induced polarization in the proton. The reported measurements suggest the presence of a new, not-yet-understood dynamical mechanism in the proton and present notable challenges to the nuclear theory.
Published: 2022
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8. Cell volume increase in murine MC3T3-E1 pre-osteoblasts attaching onto biocompatible Tantalum observed by magnetic AC mode Atomic Force Microscopy

Author: Klembt Andersen L., Antoranz Contera S., Justesen J., Duch M., Hansen O., Chevallier J., Foss M., Pedersen F. S., and Besenbacher F.
Subjects: Diseases of the musculoskeletal system, RC925-935, Orthopedic surgery, RD701-811
Abstract: Magnetic AC mode (MACmode) atomic force microscopy (AFM) was used to study murine (mouse) MC3T3-E1 preosteoblastic cells attached to biocompatible tantalum substrates. Cell volumes of attached cells derived from AFM images were compared to volumes of detached cells in suspension measured by the Coulter sizing technique. An increase of similar 50 % in cell volume was observed when the cells attached to planar tantalum substrates and developed a flattened structure including lamellipodia. We address thoroughly the issues general to the AFM determination of absolute cell volumes, and compare our magnetic AC mode AFM measurements to hitherto reported cell volume determinations by contact mode AFM.
Published: 2005

9. Determining the Proton's Gluonic Gravitational Form Factors

Author: Duran, B., Meziani, Z. -E., Joosten, S., Jones, M. K., Prasad, S., Peng, C., Armstrong, W., Atac, H., Chudakov, E., Bhatt, H., Bhetuwal, D., Boer, M., Camsonne, A., Chen, J. -P., Dalton, M. M., Deokar, N., Diefenthaler, M., Dunne, J., Fassi, L. El, Fuchey, E., Gao, H., Gaskell, D., Hansen, O., Hauenstein, F., Higinbotham, D., Jia, S., Karki, A., Keppel, C., King, P., Ko, H. S., Li, X., Li, R., Mack, D., Malace, S., McCaughan, M., McClellan, R. E., Michaels, R., Meekins, D., Paolone, M., Pentchev, L., Pooser, E., Puckett, A., Radloff, R., Rehfuss, M., Reimer, P. E., Riordan, S., Sawatzky, B., Smith, A., Sparveris, N., Szumila-Vance, H., Wood, S., Xie, J., Ye, Z., Yero, C., and Zhao, Z.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The proton is one of the main building blocks of all visible matter in the universe. Among its intrinsic properties are its electric charge, mass, and spin. These emerge from the complex dynamics of its fundamental constituents, quarks and gluons, described by the theory of quantum chromodynamics (QCD). Using electron scattering, its electric charge and spin, shared among the quark constituents, have been the topic of active investigation. An example is the novel precision measurement of the proton's electric charge radius. In contrast, little is known about the proton's inner mass density, dominated by the energy carried by the gluons, which are hard to access through electron scattering since gluons carry no electromagnetic charge. Here, we chose to probe this gluonic gravitational density using a small color dipole, the $J/\psi$ particle, through its threshold photoproduction. From our data, we determined, for the first time, the proton's gluonic gravitational form factors. We used a variety of models and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some cases, the determined radius, although model dependent, is in excellent agreement with first-principle predictions from lattice QCD. This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter., Comment: Accepted for publication
Published: 2022
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10. Proton spin structure and generalized polarizabilities in the strong quantum chromodynamics regime

Author: Ruth, D, Zielinski, R, Gu, C, Allada (Cummings), M, Badman, T, Huang, M, Liu, J, Zhu, P, Allada, K, Zhang, J, Camsonne, A, Chen, J-P, Slifer, K, Aniol, K, Annand, J, Arrington, J, Averett, T, Baghdasaryan, H, Bellini, V, Boeglin, W, Brock, J, Carlin, C, Chen, C, Cisbani, E, Crabb, D, Daniel, A, Day, D, Duve, R, Fassi, L El, Friedman, M, Fuchey, E, Gao, H, Gilman, R, Glamazdin, S, Gueye, P, Hafez, M, Han, Y, Hansen, O, Shabestari, M Hashemi, Hen, O, Higinbotham, D, Horn, T, Iqbal, S, Jensen, E, Kang, H, Keith, CD, Kelleher, A, Keller, D, Khanal, H, Korover, I, Kumbartzki, G, Li, W, Lichtenstadt, J, Lindgren, R, Long, E, Malace, S, Markowitz, P, Maxwell, J, Meekins, DM, Meziani, ZE, McLean, C, Michaels, R, Mihovilovič, M, Muangma, N, Camacho, C Munoz, Musson, J, Myers, K, Oh, Y, Carmignotto, M Pannunzio, Perdrisat, C, Phillips, S, Piasetzky, E, Pierce, J, Punjabi, V, Qiang, Y, Reimer, PE, Roblin, Y, Ron, G, Rondon, O, Russo, G, Saenboonruang, K, Sawatzky, B, Shahinyan, A, Shneor, R, Širca, S, Sjoegren, J, Solvignon-Slifer, P, Sparveris, N, Sulkosky, V, Wesselmann, F, Yan, W, Yang, H, Yao, H, Ye, Z, Yurov, M, Zhang, Y, Zhao, YX, and Zheng, X
Subjects: Mathematical Sciences, Physical Sciences, Fluids & Plasmas
Abstract: The strong interaction is not well understood at low energies or for interactions with low momentum transfer. Chiral perturbation theory gives testable predictions for the nucleonic generalized polarizabilities, which are fundamental quantities describing the nucleon’s response to an external field. We report a measurement of the proton’s generalized spin polarizabilities extracted with a polarized electron beam and a polarized solid ammonia target in the region where chiral perturbation theory is expected to be valid. The investigated structure function g2 characterizes the internal spin structure of the proton. From its moments, we extract the longitudinal–transverse spin polarizability δLT and twist-3 matrix element and polarizability d2¯. Our results provide discriminating power between existing chiral perturbation theory calculations and will help provide a better understanding of this strong quantum chromodynamics regime.
Published: 2022

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

Author: Ruth, D., Zielinski, R., Gu, C., Allada, M., Badman, T., Huang, M., Liu, J., Zhu, P., Allada, K., Zhang, J., Camsonne, A., Chen, J. P., Slifer, K., Aniol, K., Annand, J., Arrington, J., Averett, T., Baghdasaryan, H., Bellini, V., Boeglin, W., Brock, J., Carlin, C., Chen, C., Cisbani, E., Crabb, D., Daniel, A., Day, D., Duve, R., Fassi, L. El, Friedman, M., Fuchey, E., Gao, H., Gilman, R., Glamazdin, S., Gueye, P., Hafez, M., Han, Y., Hansen, O., Shabestari, M. Hashemi, Hen, O., Higinbotham, D., Horn, T., Iqbal, S., Jensen, E., Kang, H., Keith, C. D., Kelleher, A., Keller, D., Khanal, H., Korover, I., Kumbartzki, G., Li, W., Lichtenstadt, J., Lindgren, R., Long, E., Malace, S., Markowitz, P., Maxwell, J., Meekins, D. M., Meziani, Z. E., McLean, C., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Munoz, Musson, J., Myers, K., Oh, Y., Carmignotto, M. Pannunzio, Perdrisat, C., Phillips, S., Piasetzky, E., Pierce, J., Punjabi, V., Qiang, Y., Reimer, P. E., Roblin, Y., Ron, G., Rondon, O., Russo, G., Saenboonruang, K., Sawatzky, B., Shahinyan, A., Shneor, R., Sjoegren, J., Solvignon-Slifer, P., Sparveris, N., Sulkosky, V., Wesselmann, F., Yan, W., Yang, H., Yao, H., Ye, Z., Yurov, M., Zhang, Y., Zhao, Y. X., and Zheng, X.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The strong interaction is not well understood at low energy, or for interactions with low momentum transfer $Q^2$, but one of the clearest insights we have comes from Chiral Perturbation Theory ($\chi$PT). This effective treatment gives testable predictions for the nucleonic generalized polarizabilities -- fundamental quantities describing the nucleon's response to an external field. We have measured the proton's generalized spin polarizabilities in the region where $\chi$PT is expected to be valid. Our results include the first ever data for the transverse-longitudinal spin polarizability $\delta_{LT}$, and also extend the coverage of the polarizability $\bar{d_2}$ to very low $Q^2$ for the first time. These results were extracted from moments of the structure function $g_2$, a quantity which characterizes the internal spin structure of the proton. Our experiment ran at Jefferson Lab using a polarized electron beam and a polarized solid ammonia (NH$_3$) target. The $\delta_{LT}$ polarizability has remained a challenging quantity for $\chi$PT to reproduce, despite its reduced sensitivity to higher resonance contributions; recent competing calculations still disagree with each other and also diverge from the measured neutron data at very low $Q^2$. Our proton results provide discriminating power between existing calculations, and will help provide a better understanding of this strong QCD regime.
Published: 2022

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

Author: Georges, F, Rashad, MNH, Stefanko, A, Dlamini, M, Karki, B, Ali, SF, Lin, P-J, Ko, H-S, Israel, N, Adikaram, D, Ahmed, Z, Albataineh, H, Aljawrneh, B, Allada, K, Allison, S, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Atac, H, Averett, T, Ayerbe Gayoso, C, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Biswas, D, Brash, E, Bulumulla, D, Campbell, J, Camsonne, A, Carmignotto, M, Castellano, J, Chen, C, Chen, J-P, Chetry, T, Christy, ME, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Covrig Dusa, S, Crowe, B, Danagoulian, S, Danley, T, De Persio, F, Deconinck, W, Defurne, M, Desnault, C, Di, D, Duer, M, Duran, B, Ent, R, Fanelli, C, Franklin, G, Fuchey, E, Gal, C, Gaskell, D, Gautam, T, Glamazdin, O, Gnanvo, K, Gray, VM, Gu, C, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, CE, Ibrahim, H, Jen, C-M, Jin, K, Jones, M, Kabir, A, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, WB, Liu, J, Liu, H, Liyanage, A, Magee, J, Malace, S, Mammei, J, Markowitz, P, McClellan, E, Mazouz, M, and Meddi, F
Subjects: Jefferson Lab Hall A Collaboration, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract: We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes. In particular, the high accuracy of the present data demonstrates sensitivity to some very poorly known CFFs.
Published: 2022

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

Author: Suzuki, K. N., Gogami, T., Pandey, B., Itabashi, K., Nagao, S., Okuyama, K., Nakamura, S. N., Tang, L., Abrams, D., Akiyama, T., Androic, D., Aniol, K., Gayoso, C. Ayerbe, Bane, J., Barcus, S., Barrow, J., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Camsonne, A., Castellanos, J., Chen, J-P., Chen, J., Covrig, S., Chrisman, D., Cruz-Torres, R., Das, R., Fuchey, E., Gnanvo, K., Garibaldi, F., Gautam, T., Gomez, J., Gueye, P., Hague, T. J., Hansen, O., Henry, W., Hauenstein, F., Higinbotham, D. W., Hyde, C. E., Kaneta, M., Keppel, C., Kutz, T., Lashley-Colthirst, N., Li, S., Liu, H., Mammei, J., Markowitz, P., McClellan, R. E., Meddi, F., Meekins, D., Michaels, R., Mihovilovič, M., Moyer, A., Nguyen, D., Nycz, M., Owen, V., Palatchi, C., Park, S., Petkovic, T., Premathilake, S., Reimer, P. E., Reinhold, J., Riordan, S., Rodriguez, V., Samanta, C., Santiesteban, S. N., Sawatzky, B., Širca, S., Slifer, K., Su, T., Tian, Y., Toyama, Y., Uehara, K., Urciuoli, G. M., Votaw, D., Williamson, J., Wojtsekhowski, B., Wood, S. A., Yale, B., Ye, Z., Zhang, J., and Zheng, X.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: The small binding energy of the hypertrition leads to predictions of non-existence of bound hypernuclei for isotriplet three-body systems such as $nn\Lambda$. However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound $nn\Lambda$ state. The $nn\Lambda$ state was sought by missing-mass spectroscopy via the $(e,e'K^+)$ reaction at Jefferson Lab's experimental Hall A. The present experiment has higher sensitivity to the $nn\Lambda$-state investigation in terms of better precision by a factor of about three. The analysis shown in this article focuses on the derivation of the reaction cross-section for the $^3{\rm{H}}(\gamma^{*},K^+)\textrm{X}$ reaction. Events that were detected in an acceptance, where a Monte Carlo simulation could reproduce the data well ($|\delta p/p| < 4\%$), were analyzed to minimize the systematic uncertainty. No significant structures were observed with the acceptance cuts, and the upper limits of the production cross-section of the $nn\Lambda$ state were obtained to be $21$ and $31~\rm{nb/sr}$ at the $90\%$ confidence level when theoretical predictions of $(-B_{\Lambda}, \Gamma) = (0.25,0.8)$ and $(0.55, 4.7)$ MeV, respectively, were assumed. The cross-section result provides valuable information for examining the existence of $nn\Lambda$., Comment: 27 pages, 12 figures
Published: 2021
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15. Deeply virtual Compton scattering off the neutron

Author: Benali, M., Desnault, C., Mazouz, M., Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., Defurne, M., de Jager, C. W., de Leo, R., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Huber, G. M., Hyde, C. E., Iqbal, S., Itard, F., Kang, Ho., Kang, Hy., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jimenez-Arguello, A. Marti, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Pomatsalyuk, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatie, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zana, L., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: High Energy Physics - Phenomenology, High Energy Physics - Experiment, Nuclear Experiment
Abstract: The three-dimensional structure of nucleons (protons and neutrons) is embedded in so-called generalized parton distributions, which are accessible from deeply virtual Compton scattering. In this process, a high energy electron is scattered off a nucleon by exchanging a virtual photon. Then, a highly-energetic real photon is emitted from one of the quarks inside the nucleon, which carries information on the quark's transverse position and longitudinal momentum. By measuring the cross-section of deeply virtual Compton scattering, Compton form factors related to the generalized parton distributions can be extracted. Here, we report the observation of unpolarized deeply virtual Compton scattering off a deuterium target. From the measured photon-electroproduction cross-sections, we have extracted the cross-section of a quasi-free neutron and a coherent deuteron. Due to the approximate isospin symmetry of quantum chromodynamics, we can determine the contributions from the different quark flavours to the helicity-conserved Compton form factors by combining our measurements with previous ones probing the proton's internal structure. These results advance our understanding of the description of the nucleon structure, which is important to solve the proton spin puzzle.
Published: 2021
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16. Spectroscopic study of a possible Λnn resonance and a pair of ΣNN states using the (e,e′K+) reaction with a tritium target

Author: Pandey, B, Tang, L, Gogami, T, Suzuki, KN, Itabashi, K, Nagao, S, Okuyama, K, Nakamura, SN, Abrams, D, Afnan, IR, Akiyama, T, Androic, D, Aniol, K, Averett, T, Gayoso, C Ayerbe, Bane, J, Barcus, S, Barrow, J, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Camsonne, A, Castellanos, J, Chen, J-P, Chen, J, Covrig, S, Chrisman, D, Cruz-Torres, R, Das, R, Fuchey, E, Gal, C, Gibson, BF, Gnanvo, K, Garibaldi, F, Gautam, T, Gomez, J, Gueye, P, Hague, TJ, Hansen, O, Henry, W, Hauenstein, F, Higinbotham, DW, Hyde, C, Kaneta, M, Keppel, C, Kutz, T, Lashley-Colthirst, N, Li, S, Liu, H, Mammei, J, Markowitz, P, McClellan, RE, Meddi, F, Meekins, D, Michaels, R, Mihovilovič, M, Moyer, A, Nguyen, D, Nycz, M, Owen, V, Palatchi, C, Park, S, Petkovic, T, Premathilake, S, Reimer, PE, Reinhold, J, Riordan, S, Rodriguez, V, Samanta, C, Santiesteban, SN, Sawatzky, B, Širca, S, Slifer, K, Su, T, Tian, Y, Toyama, Y, Uehara, K, Urciuoli, GM, Votaw, D, Williamson, J, Wojtsekhowski, B, Wood, S, Yale, B, Ye, Z, Zhang, J, and Zheng, X
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Nuclear and plasma physics
Abstract: A mass spectroscopy experiment with a pair of nearly identical high-resolution spectrometers and a tritium target was performed in Hall A at Jefferson Lab. Utilizing the (e,e′K+) reaction, enhancements, which may correspond to a possible Λnn resonance and a pair of ςNN states, were observed with an energy resolution of about 1.21 MeV (σ), although greater statistics are needed to make definitive identifications. An experimentally measured Λnn state may provide a unique constraint in determining the Λn interaction, for which no scattering data exist. In addition, although bound A=3 and 4 ς hypernuclei have been predicted, only an A=4 ς hypernucleus (Heς4) was found, utilizing the (K-,π-) reaction on a He4 target. The possible bound ςNN state is likely a ς0nn state, although this has to be confirmed by future experiments.
Published: 2022

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

Author: Christy, ME, Gautam, T, Ou, L, Schmookler, B, Wang, Y, Adikaram, D, Ahmed, Z, Albataineh, H, Ali, SF, Aljawrneh, B, Allada, K, Allison, SL, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Bhatt, H, Bhetuwal, D, Biswas, D, Brash, E, Bulumulla, D, Camacho, CM, Campbell, J, Camsonne, A, Carmignotto, M, Castellanos, J, Chen, C, Chen, J-P, Chetry, T, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Dusa, S Covrig, Crowe, B, Danagoulian, S, Danley, T, Deconinck, W, Defurne, M, Desnault, C, Di, D, Dlamini, M, Duer, M, Duran, B, Ent, R, Fanelli, C, Fuchey, E, Gal, C, Gaskell, D, Georges, F, Gilad, S, Glamazdin, O, Gnanvo, K, Gramolin, AV, Gray, VM, Gu, C, Habarakada, A, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Hernandez, AV, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, C, Ibrahim, H, Israel, N, Jen, C-M, Jin, K, Jones, M, Kabir, A, Karki, B, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, W, Liu, H, Liu, J, Liyanage, AH, Mack, D, and Magee, J
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75 (GeV/c)^{2}. Combined with existing data, these provide an improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8 (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.
Published: 2022

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

Author: Suzuki, KN, Gogami, T, Pandey, B, Itabashi, K, Nagao, S, Okuyama, K, Nakamura, SN, Tang, L, Abrams, D, Akiyama, T, Androic, D, Aniol, K, Gayoso, C Ayerbe, Bane, J, Barcus, S, Barrow, J, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Camsonne, A, Castellanos, J, Chen, J-P, Chen, J, Covrig, S, Chrisman, D, Cruz-Torres, R, Das, R, Fuchey, E, Gnanvo, K, Garibaldi, F, Gautam, T, Gomez, J, Gueye, P, Hague, TJ, Hansen, O, Henry, W, Hauenstein, F, Higinbotham, DW, Hyde, CE, Kaneta, M, Keppel, C, Kutz, T, Lashley-Colthirst, N, Li, S, Liu, H, Mammei, J, Markowitz, P, McClellan, RE, Meddi, F, Meekins, D, Michaels, R, Mihovilovič, M, Moyer, A, Nguyen, D, Nycz, M, Owen, V, Palatchi, C, Park, S, Petkovic, T, Premathilake, S, Reimer, PE, Reinhold, J, Riordan, S, Rodriguez, V, Samanta, C, Santiesteban, SN, Sawatzky, B, Širca, S, Slifer, K, Su, T, Tian, Y, Toyama, Y, Uehara, K, Urciuoli, GM, Votaw, D, Williamson, J, Wojtsekhowski, B, Wood, SA, Yale, B, Ye, Z, Zhang, J, and Zheng, X
Subjects: Mathematical Sciences, Physical Sciences
Abstract: The small binding energy of the hypertriton leads to predictions of the non-existence of bound hypernuclei for isotriplet three-body systems such as nnΛ. However, invariant mass spectroscopy at GSI has reported events that may be interpreted as the bound nnΛ state. The nnΛ state was sought by missing-mass spectroscopy via the (e, e′K+) reaction at Jefferson Lab's experimental Hall A. The present experiment has higher sensitivity to the nnΛ-state investigation in terms of better precision by a factor of about three. The analysis shown in this article focuses on the derivation of the reaction cross-section for the 3H(γ∗, K+)X reaction. Events that were detected in an acceptance, where a Monte Carlo simulation could reproduce the data well (δ p/p| < 4), were analyzed to minimize the systematic uncertainty. No significant structures were observed with the acceptance cuts, and the upper limits of the production cross-section of the nnΛ state were obtained to be 21 and 31 nb sr-1 at the $90\%$ confidence level when theoretical predictions of (-BΛ, Γ) = (0.25, 0.8) MeV and (0.55, 4.7) MeV, respectively, were assumed. The cross-section result provides valuable information for examining the existence of nnΛ.
Published: 2022

19. 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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20. Deep Exclusive Electroproduction of π0 at High Q2 in the Quark Valence Regime

Author: Dlamini, M, Karki, B, Ali, SF, Lin, P-J, Georges, F, Ko, H-S, Israel, N, Rashad, MNH, Stefanko, A, Adikaram, D, Ahmed, Z, Albataineh, H, Aljawrneh, B, Allada, K, Allison, S, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Atac, H, Averett, T, Ayerbe Gayoso, C, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Biswas, D, Brash, E, Bulumulla, D, Campbell, J, Camsonne, A, Carmignotto, M, Castellano, J, Chen, C, Chen, J-P, Chetry, T, Christy, ME, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Covrig Dusa, S, Crowe, B, Danagoulian, S, Danley, T, De Persio, F, Deconinck, W, Defurne, M, Desnault, C, Di, D, Duer, M, Duran, B, Ent, R, Fanelli, C, Franklin, G, Fuchey, E, Gal, C, Gaskell, D, Gautam, T, Glamazdin, O, Gnanvo, K, Gray, VM, Gu, C, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, C, Ibrahim, H, Jen, C-M, Jin, K, Jones, M, Kabir, A, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, W, Liu, J, Liu, H, Liyanage, A, Magee, J, Malace, S, Mammei, J, Markowitz, P, McClellan, E, Meddi, F, and Meekins, D
Subjects: Jefferson Lab Hall A Collaboration, Mathematical Sciences, Physical Sciences, Engineering, General Physics
Abstract: We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of x_{B} (0.36, 0.48, and 0.60) and Q^{2} (3.1 to 8.4 GeV^{2}) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions dσ_{T}/dt+εdσ_{L}/dt, dσ_{TT}/dt, dσ_{LT}/dt, and dσ_{LT^{'}}/dt are extracted as a function of the proton momentum transfer t-t_{min}. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.
Published: 2021

21. Early Mortality After Curative-intent Radiotherapy in Patients With Locally Advanced Non-small Cell Lung Cancer—A Population-based Cohort Study

Author: Jensen, K.H., Persson, G., Pøhl, M., Frank, M.S., Hansen, O., Schytte, T., Kristiansen, C., Knap, M., Skovborg, M., Vogelius, I.R., and Friborg, J.
Published: 2024
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22. Determining the gluonic gravitational form factors of the proton

Author: Duran, B., Meziani, Z.-E., Joosten, S., Jones, M. K., Prasad, S., Peng, C., Armstrong, W., Atac, H., Chudakov, E., Bhatt, H., Bhetuwal, D., Boer, M., Camsonne, A., Chen, J.-P., Dalton, M. M., Deokar, N., Diefenthaler, M., Dunne, J., El Fassi, L., Fuchey, E., Gao, H., Gaskell, D., Hansen, O., Hauenstein, F., Higinbotham, D., Jia, S., Karki, A., Keppel, C., King, P., Ko, H. S., Li, X., Li, R., Mack, D., Malace, S., McCaughan, M., McClellan, R. E., Michaels, R., Meekins, D., Paolone, Michael, Pentchev, L., Pooser, E., Puckett, A., Radloff, R., Rehfuss, M., Reimer, P. E., Riordan, S., Sawatzky, B., Smith, A., Sparveris, N., Szumila-Vance, H., Wood, S., Xie, J., Ye, Z., Yero, C., and Zhao, Z.
Published: 2023
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23. 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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24. Backward-angle Exclusive pi0 Production above the Resonance Region

Author: Li, W. B., Huber, G. M., Stevens, J. R., Semenov-Tian-Shansky, K., Szymanowski, L., Pire, B., Amaryan, M., Androic, D., Aniol, K., Armstrong, D., Averett, T., Gayoso, C. Ayerbe, Boeglin, W., Boer, M., Camsonne, A., Chen, J., Dusa, S. Covrig, Deconinck, W., Defurne, M., Delcarro, F., Diefenthaler, M., Diehl, S., Elaasar, M., Fanelli, C., Fegan, S., Fuchey, E., Gaskell, D., Hansen, O., Hauenstein, F., Higinbotham, D., Blin, A. Hiller, Hurley, A., Hyde, C., Joo, K., Junaid, M., Kalantarians, N., Kay, S., Khachatryan, M., King, P., Kumar, V., Lersch, D., Lorenti, L., Markowitz, P., McCaughan, M., Mkrtchyan, A., Mkrtchyan, H., Niculescu, G., Niculescu, I., Papandreou, Z., Paremuzyan, R., Park, K., Paudyal, D., Roche, J., Rodas, A., Sawatzky, B., Schertz, A., Smith, G., Strakovsky, I., Tadevosyan, V., Usman, A., Voskanyan, H., and Yero, C.
Subjects: Nuclear Experiment
Abstract: The proposed measurement is a dedicated study of the exclusive electroproduction process,1H(e,e'p)pi0, in the backward-angle regime (u-channel process) above the resonance region. The produced pi0 is emitted 180 degrees opposite to the virtual-photon momentum. This study also aims to apply the well-known Rosenbluth separation technique that provides the model-independent differential cross-sections at the never explored u-channel kinematics region. Currently, the "soft-hard transition" in u-channel meson production remains an interesting and unexplored subject. The available theoretical frameworks offer competing interpretations for the observed backward-angle cross section peaks. In a "soft" hadronic Regge exchange description, the backward meson production comes from the interference between nucleon exchange and the meson produced via re-scattering within the nucleon. Whereas in the "hard" GPD-like backward collinear factorization regime, the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes (TDAs), otherwise known as super skewed parton distributions (SuperSPDs). Both TDAs and SPDs are universal non-perturbative objects of nucleon structure accessible only through backward-angle kinematics. The separated cross sections:sigma_T,sigma_L and T/L ratio at Q2=2-6 GeV2, provide a direct test of two predictions from the TDA model. The magnitude and u-dependence of the separated cross sections also provide a direct connection to the re-scattering Regge picture. The extracted interaction radius (from u-dependence) at different Q2 can be used to study the soft-hard transition in the u-channel kinematics. The acquisition of these data will be an important step forward in validating the existence of a backward factorization scheme of the nucleon structure function and establishing its applicable kinematic range.
Published: 2020

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

Author: Accardi, A., Afanasev, A., Albayrak, I., Ali, S. F., Amaryan, M., Annand, J. R. M., Arrington, J., Asaturyan, A., Atac, H., Avakian, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Barion, L., Battaglieri, M., Bellini, V., Beminiwattha, R., Benmokhtar, F., Berdnikov, V. V., Bernauer, J. C., Bertone, V., Bianconi, A., Biselli, A., Bisio, P., Blunden, P., Boer, M., Bondì, M., Brinkmann, K. -T., Briscoe, W. J., Burkert, V., Cao, T., Camsonne, A., Capobianco, R., Cardman, L., Carmignotto, M., Caudron, M., Causse, L., Celentano, A., Chatagnon, P., Chen, J. -P., Chetry, T., Ciullo, G., Cline, E., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Darmé, L., Day, D., Defurne, M., De Napoli, M., Deur, A., De Vita, R., D'Hose, N., Diehl, S., Diefenthaler, M., Dongwi, B., Dupré, R., Dutrieux, H., Dutta, D., Ehrhart, M., Fassi, L. El, Elouadrhiri, L., Ent, R., Erler, J., Fernando, I. P., Filippi, A., Flay, D., Forest, T., Fuchey, E., Fucini, S., Furletova, Y., Gao, H., Gaskell, D., Gasparian, A., Gautam, T., Girod, F. -X., Gnanvo, K., Grames, J., Grauvoge, G. N., Gueye, P., Guidal, M., Habet, S., Hague, T. J., Hamilton, D. J., Hansen, O., Hasell, D., Hattawy, M., Higinbotham, D. W., Hobart, A., Horn, T., Hyde, C. E., Ibrahim, H., Ilyichev, A., Italiano, A., Joo, K., Joosten, S. J., Khachatryan, V., Kalantarians, N., Kalicy, G., Karky, B., Keller, D., Keppel, C., Kerver, M., Khandaker, M., Kim, A., Kim, J., King, P. M., Kinney, E., Klimenko, V., Ko, H. -S., Kohl, M., Kozhuharov, V., Kriesten, B. T., Krnjaic, G., Kubarovsky, V., Kutz, T., Lanza, L., Leali, M., Lenisa, P., Liyanage, N., Liu, Q., Liuti, S., Mammei, J., Mantry, S., Marchand, D., Markowitz, P., Marsicano, L., Mascagna, V., Mazouz, M., McCaughan, M., McKinnon, B., McNulty, D., Melnitchouk, W., Metz, A., Meziani, Z. -E., Migliorati, S., Mihovilovic, M., Milner, R., Mkrtchyan, A., Mkrtchyan, H., Movsisyan, A., Moutarde, H., Muhoza, M., Camacho, C. Muñoz, Murphy, J., Nadel-Turonski, P., Nardi, E., Nazeer, J., Niccolai, S., Niculescu, G., Novotny, R., Owens, J. F., Paolone, M., Pappalardo, L., Paremuzyan, R., Pasquini, B., Pasyuk, E., Patel, T., Pegg, I., Peng, C., Perera, D., Poelker, M., Price, K., Puckett, A. J. R., Raggi, M., Randazzo, N., Rashad, M. N. H., Rathnayake, M., Raue, B., Reimer, P. E., Rinaldi, M., Rizzo, A., Roblin, Y., Roche, J., Rondon-Aramayo, O., Sabatié, F., Salmè, G., Santopinto, E., Estrada, R. Santos, Sawatzky, B., Schmidt, A., Schweitzer, P., Scopetta, S., Sergeyeva, V., Shabestari, M., Shahinyan, A., Sharabian, Y., Širca, S., Smith, E. S., Sokhan, D., Somov, A., Sparveris, N., Spata, M., Spiesberger, H., Spreafico, M., Stepanyan, S., Stoler, P., Strakovsky, I., Suleiman, R., Suresh, M., Sznajder, P., Szumila-Vance, H., Tadevosyan, V., Tadepalli, A. S., Thomas, A. W., Tiefenback, M., Trotta, R., Ungaro, M., Valente, P., Vanderhaeghen, M., Venturelli, L., Voskanyan, H., Voutier, E., Wojtsekhowski, B., Wood, M. H., Wood, S., Xie, J., Xiong, W., Ye, Z., Yurov, M., Zaunick, H. -G., Zhamkochyan, S., Zhang, J., Zhang, S., Zhao, S., Zhao, Z. W., Zheng, X., Zhou, J., and Zorn, C.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental programs at the next generation of lepton accelerators. In the context of the hadronic physics program at Jefferson Lab (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of nucleons and nuclei, in both the elastic and deep-inelastic regimes. For instance, elastic scattering of polarized and unpolarized electrons and positrons from the nucleon enables a model independent determination of its electromagnetic form factors. Also, the deeply-virtual scattering of polarized and unpolarized electrons and positrons allows unambiguous separation of the different contributions to the cross section of the lepto-production of photons and of lepton-pairs, enabling an accurate determination of the nucleons and nuclei generalized parton distributions, and providing an access to the gravitational form factors. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model of particle physics through the search of a dark photon, the precise measurement of electroweak couplings, and the investigation of charged lepton flavor violation. This document discusses the perspectives of an experimental program with high duty-cycle positron beams at JLab., Comment: 18 pages, 7 figures This version superseeds the previous version which scientific content was decomposed into several more elaborated articles. All of these articles will be collected in the EPJ A Topical Issue about "Positron beam and physics at Jefferson Lab (e+@Jlab)"
Published: 2020
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26. Probing few-body nuclear dynamics via 3H and 3He (e,e'p)pn cross-section measurements

Author: Cruz-Torres, R., Nguyen, D., Hauenstein, F., Schmidt, A., Li, S., Abrams, D., Albataineh, H., Alsalmi, S., Androic, D., Aniol, K., Armstrong, W., Arrington, J., Atac, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Beck, A., Bellini, V., Benmokhtar, F., Bhatt, H., Bhetuwal, D., Biswas, D., Blyth, D., Boeglin, W., Bulumulla, D., Camsonne, A., Castellanos, J., Chen, J-P., Cohen, E. O., Covrig, S., Craycraft, K., Dongwi, B., Duer, M., Duran, B., Dutta, D., Fuchey, E., Gal, C., Gautam, T. N., Gilad, S., Gnanvo, K., Gogami, T., Golak, J., Gomez, J., Gu, C., Hague, A. Habarakada T., Hansen, O., Hattawy, M., Hen, O., Higinbotham, D. W., Hughes, E., Hyde, C., Ibrahim, H., Jian, S., Joosten, S., Kamada, H., Karki, A., Karki, B., Katramatou, A. T., Keppel, C., Khachatryan, M., Khachatryan, V., Khanal, A., King, D., King, P., Korover, I., Kutz, T., Lashley-Colthirst, N., Laskaris, G., Li, W., Liu, H., Liyanage, N., Markowitz, P., McClellan, R. E., Meekins, D., Meziani, S. Mey-Tal Beck Z-E., Michaels, R., Mihovilovic, M., Nelyubin, V., Nuruzzaman, N., Nycz, M., Obrecht, R., Olson, M., Ou, L., Owen, V., Pandey, B., Pandey, V., Papadopoulou, A., Park, S., Patsyuk, M., Paul, S., Petratos, G. G., Piasetzky, E., Pomatsalyuk, R., Premathilake, S., Puckett, A. J. R., Punjabi, V., Ransome, R., Rashad, M. N. H., Reimer, P. E., Riordan, S., Roche, J., Sargsian, M., Santiesteban, N., Sawatzky, B., Segarra, E. P., Schmookler, B., Shahinyan, A., Sirca, S., Skibinski, R., Sparveris, N., Su, T., Suleiman, R., Szumila-Vance, H., Tadepalli, A. S., Tang, L., Tireman, W., Topolnicki, K., Tortorici, F., Urciuoli, G., Weinstein, L. B., Witala, H., Wojtsekhowski, B., Wood, S., Ye, Z. H., Ye, Z. Y., and Zhang, J.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: We report the first measurement of the \eep three-body breakup reaction cross sections in helium-3 ($^3$He) and tritium ($^3$H) at large momentum transfer ($\langle Q^2 \rangle \approx 1.9$ (GeV/c)$^2$) and $x_B>1$ kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta $40 \le p_{miss} \le 500$ MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab-initio calculations. Overall good agreement, within $\pm20\%$, is observed between data and calculations for the full $p_{miss}$ range for $^3$H and for $100 \le p_{miss} \le 350$ MeV/c for $^3$He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at $p_{miss} > 250$ MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of $^3$He plus $^3$H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire $p_{miss}$ range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of $500$ MeV/c., Comment: Accepted for publication in PRL. 8 pages, 3 figures, and online supplementary materials
Published: 2020
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27. An experimental program with high duty-cycle polarized and unpolarized positron beams at Jefferson Lab

Author: Accardi, A, Afanasev, A, Albayrak, I, Ali, SF, Amaryan, M, Annand, JRM, Arrington, J, Asaturyan, A, Atac, H, Avakian, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Barion, L, Battaglieri, M, Bellini, V, Beminiwattha, R, Benmokhtar, F, Berdnikov, VV, Bernauer, JC, Bertone, V, Bianconi, A, Biselli, A, Bisio, P, Blunden, P, Boer, M, Bondì, M, Brinkmann, K-T, Briscoe, WJ, Burkert, V, Cao, T, Camsonne, A, Capobianco, R, Cardman, L, Carmignotto, M, Caudron, M, Causse, L, Celentano, A, Chatagnon, P, Chen, J-P, Chetry, T, Ciullo, G, Cline, E, Cole, PL, Contalbrigo, M, Costantini, G, D’Angelo, A, Darmé, L, Day, D, Defurne, M, De Napoli, M, Deur, A, De Vita, R, D’Hose, N, Diehl, S, Diefenthaler, M, Dongwi, B, Dupré, R, Dutrieux, H, Dutta, D, Ehrhart, M, El Fassi, L, Elouadrhiri, L, Ent, R, Erler, J, Fernando, IP, Filippi, A, Flay, D, Forest, T, Fuchey, E, Fucini, S, Furletova, Y, Gao, H, Gaskell, D, Gasparian, A, Gautam, T, Girod, F-X, Gnanvo, K, Grames, J, Grauvogel, GN, Gueye, P, Guidal, M, Habet, S, Hague, TJ, Hamilton, DJ, Hansen, O, Hasell, D, Hattawy, M, Higinbotham, DW, Hobart, A, Horn, T, Hyde, CE, Ibrahim, H, Ilyichev, A, Italiano, A, Joo, K, Joosten, SJ, Khachatryan, V, Kalantarians, N, and Kalicy, G
Subjects: Nuclear and Plasma Physics, Particle and High Energy Physics, Synchrotrons and Accelerators, Physical Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Nuclear and plasma physics, Particle and high energy physics, Synchrotrons and accelerators
Abstract: Positron beams, both polarized and unpolarized, are identified as important ingredients for the experimental programs at the next generation of lepton accelerators. In the context of the hadronic physics program at Jefferson Lab (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of nucleons and nuclei, in both the elastic and deep-inelastic regimes. For instance, elastic scattering of polarized and unpolarized electrons and positrons from the nucleon enables a model independent determination of its electromagnetic form factors. Also, the deeply-virtual scattering of polarized and unpolarized electrons and positrons allows unambiguous separation of the different contributions to the cross section of the lepto-production of photons and of lepton-pairs, enabling an accurate determination of the nucleons and nuclei generalized parton distributions, and providing an access to the gravitational form factors of the energy-momentum tensor. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model of particle physics through the search of a dark photon, the precise measurement of electroweak couplings, and the investigation of charged lepton flavor violation. This document discusses the perspectives of an experimental program with high duty-cycle positron beams at JLab.
Published: 2021

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

Author: Christy, ME, Gautam, T, Ou, L, Schmookler, B, Wang, Y, Adikaram, D, Ahmed, Z, Albataineh, H, Ali, SF, Aljawrneh, B, Allada, K, Allison, SL, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Bhatt, H, Bhetuwal, D, Biswas, D, Brash, E, Bulumulla, D, Camacho, CM, Campbell, J, Camsonne, A, Carmignotto, M, Castellanos, J, Chen, C, Chen, J-P, Chetry, T, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Dusa, S Covrig, Crowe, B, Danagoulian, S, Danley, T, Deconinck, W, Defurne, M, Desnault, C, Di, D, Dlamini, M, Duer, M, Duran, B, Ent, R, Fanelli, C, Fuchey, E, Gal, C, Gaskell, D, Georges, F, Gilad, S, Glamazdin, O, Gnanvo, K, Gramolin, AV, Gray, VM, Gu, C, Habarakada, A, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Hernandez, AV, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, C, Ibrahim, H, Israel, N, Jen, C-M, Jin, K, Jones, M, Kabir, A, Karki, B, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, W, Liu, H, Liu, J, Liyanage, AH, Mack, D, and Magee, J
Subjects: nucl-ex, hep-ex
Abstract: We present new precision measurements of the elastic electron-protonscattering cross section for momentum transfer (Q$^2$) up to 15.75~\gevsq.Combined with existing data, these provide an improved extraction of the protonmagnetic form factor at high Q$^2$ and double the range over which alongitudinal/transverse separation of the cross section can be performed. Thedifference between our results and polarization data agrees with that observedat lower Q$^2$ and attributed to hard two-photon exchange (TPE) effects,extending to 8~(GeV/c)$^2$ the range of Q$^2$ for which a discrepancy isestablished at $>$95\% confidence. We use the discrepancy to quantify the sizeof TPE contributions needed to explain the cross section at high Q$^2$.
Published: 2021

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

Author: Cruz-Torres, R., Li, S., Hauenstein, F., Schmidt, A., Nguyen, D., Abrams, D., Albataineh, H., Alsalmi, S., Androic, D., Aniol, K., Armstrong, W., Arrington, J., Atac, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Bane, J., Barcus, S., Beck, A., Bellini, V., Bhatt, H., Bhetuwal, D., Biswas, D., Blyth, D., Boeglin, W., Bulumulla, D., Camsonne, A., Castellanos, J., Chen, J. -P., Cohen, E. O., Covrig, S., Craycraft, K., Dongwi, B., Duer, M., Duran, B., Dutta, D., Fuchey, E., Gal, C., Gautam, T. N., Gilad, S., Gnanvo, K., Gogami, T., Gomez, J., Gu, C., Habarakada, A., Hague, T., Hansen, O., Hattawy, M., Hen, O., Higinbotham, D. W., Hughes, E., Hyde, C., Ibrahim, H., Jian, S., Joosten, S., Karki, A., Karki, B., Katramatou, A. T., Keppel, C., Khachatryan, M., Khachatryan, V., Khanal, A., King, D., King, P., Korover, I., Kutz, T., Lashley-Colthirst, N., Laskaris, G., Li, W., Liu, H., Liyanage, N., Lonardoni, D., Machleidt, R., Marcucci, L. E., Markowitz, P., McClellan, R. E., Meekins, D., Beck, S. Mey-Tal, Meziani, Z. -E., Michaels, R., Mihovilovic, M., Nelyubin, V., Nuruzzaman, N., Nycz, M., Obrecht, R., Olson, M., Ou, L., Owen, V., Pandey, B., Pandey, V., Papadopoulou, A., Park, S., Patsyuk, M., Paul, S., Petratos, G. G., Piasetzky, E., Pomatsalyuk, R., Premathilake, S., Puckett, A. J. R., Punjabi, V., Ransome, R., Rashad, M. N. H., Reimer, P. E., Riordan, S., Roche, J., Sammarruca, F., Santiesteban, N., Sawatzky, B., Segarra, E. P., Schmookler, B., Shahinyan, A., Širch, S., Sparveris, N., Su, T., Suleiman, R., Szumila-Vance, H., Tadepalli, A. S., Tang, L., Tireman, W., Tortorici, F., Urciuoli, G., Viviani, M., Weinstein, L. B., Wojtsekhowski, B., Wood, S., Ye, Z. H., Ye, Z. Y., and Zhang, J.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: We report the first measurement of the $(e,e'p)$ reaction cross-section ratios for Helium-3 ($^3$He), Tritium ($^3$H), and Deuterium ($d$). The measurement covered a missing momentum range of $40 \le p_{miss} \le 550$ MeV$/c$, at large momentum transfer ($\langle Q^2 \rangle \approx 1.9$ (GeV$/c$)$^2$) and $x_B>1$, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for $^3$He$/d$ and $^3$H$/d$ extend to just above the typical nucleon Fermi-momentum ($k_F \approx 250$ MeV$/c$) and differ from each other by $\sim 20\%$, while for $^3$He/$^3$H they agree within the measurement accuracy of about 3\%. At momenta above $k_F$, the measured $^3$He/$^3$H ratios differ from the calculation by $20\% - 50\%$. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the $^3$He/$^3$H cross-section ratio for this measurement by less than 5\%. If these calculations are correct, then the differences at large missing momenta between the $^3$He/$^3$H experimental and calculated ratios could be due to the underlying $NN$ interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the $NN$ interaction., Comment: 8 pages, 3 figures (4 panels)
Published: 2019
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30. Deep exclusive electroproduction of $π^0$ at high $Q^2$ in the quark valence regime

Author: Collaboration, The Jefferson Lab Hall A, Dlamini, M, Karki, B, Ali, SF, Lin, P-J, Georges, F, Ko, H-S, Israel, N, Rashad, MNH, Stefanko, A, Adikaram, D, Ahmed, Z, Albataineh, H, Aljawrneh, B, Allada, K, Allison, S, Alsalmi, S, Androic, D, Aniol, K, Annand, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Bartlett, K, Bellini, V, Beminiwattha, R, Bericic, J, Biswas, D, Brash, E, Bulumulla, D, Campbell, J, Camsonne, A, Carmignotto, M, Castellano, J, Chen, C, Chen, J-P, Chetry, T, Christy, ME, Cisbani, E, Clary, B, Cohen, E, Compton, N, Cornejo, JC, Dusa, S Covrig, Crowe, B, Danagoulian, S, Danley, T, Persio, F De, Deconinck, W, Defurne, M, Desnault, C, Di, D, Duer, M, Duran, B, Ent, R, Fanelli, C, Franklin, G, Fuchey, E, Gal, C, Gaskell, D, Gautam, T, Glamazdin, O, Gnanvo, K, Gray, VM, Gu, C, Hague, T, Hamad, G, Hamilton, D, Hamilton, K, Hansen, O, Hauenstein, F, Henry, W, Higinbotham, DW, Holmstrom, T, Horn, T, Huang, Y, Huber, GM, Hyde, C, Ibrahim, H, Jen, C-M, Jin, K, Jones, M, Kabir, A, Keppel, C, Khachatryan, V, King, PM, Li, S, Li, W, Liu, J, Liu, H, Liyanage, A, Magee, J, Malace, S, Mammei, J, Markowitz, P, McClellan, E, and Meddi, F
Subjects: hep-ex, nucl-ex
Abstract: We report measurements of the exclusive neutral pion electroproduction crosssection off protons at large values of $x_B$ (0.36, 0.48 and 0.60) and $Q^2$(3.1 to 8.4 GeV$^2$) obtained from Jefferson Lab Hall A experiment E12-06-014.The corresponding structure functions $d\sigma_L/dt+\epsilon d\sigma_T/dt$,$d\sigma_{TT}/dt$, $d\sigma_{LT}/dt$ and $d\sigma_{LT'}/dt$ are extracted as afunction of the proton momentum transfer $t-t_{min}$. The results suggest theamplitude for transversely polarized virtual photons continues to dominate thecross-section throughout this kinematic range. The data are well described bycalculations based on transversity Generalized Parton Distributions coupled toa helicity flip Distribution Amplitude of the pion, thus providing a unique wayto probe the structure of the nucleon.
Published: 2020

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

Author: Accardi, A, Afanasev, A, Albayrak, I, Ali, SF, Amaryan, M, Annand, JRM, Arrington, J, Asaturyan, A, Atac, H, Avakian, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Barion, L, Battaglieri, M, Bellini, V, Beminiwattha, R, Benmokhtar, F, Berdnikov, VV, Bernauer, JC, Bertone, V, Bianconi, A, Biselli, A, Bisio, P, Blunden, P, Boer, M, Bondì, M, Brinkmann, K-T, Briscoe, WJ, Burkert, V, Cao, T, Camsonne, A, Capobianco, R, Cardman, L, Carmignotto, M, Caudron, M, Causse, L, Celentano, A, Chatagnon, P, Chen, J-P, Chetry, T, Ciullo, G, Cline, E, Cole, PL, Contalbrigo, M, Costantini, G, D'Angelo, A, Darmé, L, Day, D, Defurne, M, Napoli, M De, Deur, A, Vita, R De, D'Hose, N, Diehl, S, Diefenthaler, M, Dongwi, B, Dupré, R, Dutrieux, H, Dutta, D, Ehrhart, M, Fassi, L El, Elouadrhiri, L, Ent, R, Erler, J, Fernando, IP, Filippi, A, Flay, D, Forest, T, Fuchey, E, Fucini, S, Furletova, Y, Gao, H, Gaskell, D, Gasparian, A, Gautam, T, Girod, F-X, Gnanvo, K, Grames, J, Grauvoge, GN, Gueye, P, Guidal, M, Habet, S, Hague, TJ, Hamilton, DJ, Hansen, O, Hasell, D, Hattawy, M, Higinbotham, DW, Hobart, A, Horn, T, Hyde, CE, Ibrahim, H, Ilyichev, A, Italiano, A, Joo, K, Joosten, SJ, Khachatryan, V, Kalantarians, N, and Kalicy, G
Subjects: nucl-ex, hep-ex, hep-ph
Abstract: Positron beams, both polarized and unpolarized, are identified as essentialingredients for the experimental programs at the next generation of leptonaccelerators. In the context of the hadronic physics program at Jefferson Lab(JLab), positron beams are complementary, even essential, tools for a preciseunderstanding of the electromagnetic structure of nucleons and nuclei, in boththe elastic and deep-inelastic regimes. For instance, elastic scattering ofpolarized and unpolarized electrons and positrons from the nucleon enables amodel independent determination of its electromagnetic form factors. Also, thedeeply-virtual scattering of polarized and unpolarized electrons and positronsallows unambiguous separation of the different contributions to the crosssection of the lepto-production of photons and of lepton-pairs, enabling anaccurate determination of the nucleons and nuclei generalized partondistributions, and providing an access to the gravitational form factors.Furthermore, positron beams offer the possibility of alternative tests of theStandard Model of particle physics through the search of a dark photon, theprecise measurement of electroweak couplings, and the investigation of chargedlepton flavor violation. This document discusses the perspectives of anexperimental program with high duty-cycle positron beams at JLab.
Published: 2020

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

Author: Cruz-Torres, R, Nguyen, D, Hauenstein, F, Schmidt, A, Li, S, Abrams, D, Albataineh, H, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Benmokhtar, F, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, J-P, Cohen, EO, Covrig, S, Craycraft, K, Dongwi, B, Duer, M, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Golak, J, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, O, Hattawy, M, Hen, O, Higinbotham, DW, Hughes, E, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Kamada, H, Karki, A, Karki, B, Katramatou, AT, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, King, D, King, P, Korover, I, Kutz, T, Lashley-Colthirst, N, Laskaris, G, Li, W, Liu, H, Liyanage, N, Markowitz, P, McClellan, RE, Meekins, D, Beck, S Mey-Tal, Meziani, Z-E, Michaels, R, Mihovilovič, M, Nelyubin, V, Nuruzzaman, N, Nycz, M, Obrecht, R, Olson, M, Ou, L, Owen, V, Pandey, B, Pandey, V, Papadopoulou, A, Park, S, Patsyuk, M, Paul, S, Petratos, GG, Piasetzky, E, Pomatsalyuk, R, Premathilake, S, Puckett, AJR, and Punjabi, V
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Jefferson Lab Hall A Tritium Collaboration, nucl-ex, nucl-th, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract: We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9 (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500 MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full p_{miss} range for ^{3}H and for 100≤p_{miss}≤350 MeV/c for ^{3}He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at p_{miss}>250 MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of ^{3}He plus ^{3}H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire p_{miss} range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500 MeV/c.
Published: 2020

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

Author: Cruz-Torres, R, Nguyen, D, Hauenstein, F, Schmidt, A, Li, S, Abrams, D, Albataineh, H, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Ayerbe Gayoso, C, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Benmokhtar, F, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, J-P, Cohen, EO, Covrig, S, Craycraft, K, Dongwi, B, Duer, M, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Golak, J, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, O, Hattawy, M, Hen, O, Higinbotham, DW, Hughes, E, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Kamada, H, Karki, A, Karki, B, Katramatou, AT, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, King, D, King, P, Korover, I, Kutz, T, Lashley-Colthirst, N, Laskaris, G, Li, W, Liu, H, Liyanage, N, Markowitz, P, McClellan, RE, Meekins, D, Mey-Tal Beck, S, Meziani, Z-E, Michaels, R, Mihovilovič, M, Nelyubin, V, Nuruzzaman, N, Nycz, M, Obrecht, R, Olson, M, Ou, L, Owen, V, Pandey, B, Pandey, V, Papadopoulou, A, Park, S, Patsyuk, M, Paul, S, Petratos, GG, Piasetzky, E, Pomatsalyuk, R, Premathilake, S, Puckett, AJR, and Punjabi, V
Subjects: Jefferson Lab Hall A Tritium Collaboration, nucl-ex, nucl-th, General Physics, Mathematical Sciences, Physical Sciences, Engineering
Abstract: We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9 (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500 MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full p_{miss} range for ^{3}H and for 100≤p_{miss}≤350 MeV/c for ^{3}He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at p_{miss}>250 MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of ^{3}He plus ^{3}H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire p_{miss} range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500 MeV/c.
Published: 2020

34. Regionale Frühversorgung weiterentwickeln – Viele Wege führen nach Rom: Entwicklungsetappen von 4 etablierten rheumatologischen Frühversorgungskonzepten in verschiedenen Regionen Deutschlands

Author: Benesova, K., Hansen, O., Sander, O., Feuchtenberger, M., Nigg, A., Voigt, A., Seipelt, E., Schneider, M., Lorenz, H.-M., and Krause, A.
Published: 2022
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35. Measurement of double-polarization asymmetries in the quasi-elastic $^3\vec{\mathrm{He}}(\vec{\mathrm{e}},\mathrm{e}'\mathrm{p})$ process

Author: Mihovilovič, M., Jin, G., Long, E., Zhang, Y. -W., Allada, K., Anderson, B., Annand, J. R. M., Averett, T., Bertozzi, W., Boeglin, W., Bradshaw, P., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. P., Chudakov, E., De Leo, R., Deng, X., Deltuva, A., Deur, A., Dutta, C., Fassi, L. El, Flay, D., Frullani, S., Garibaldi, F., Gao, H., Gilad, S., Gilman, R., Glamazdin, O., Golak, J., Golge, S., Gomez, J., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Ibrahim, H., de Jager, C. W., Jensen, E., Jiang, X., Jones, M., Kamada, H., Kang, H., Katich, J., Khanal, H. P., Kievsky, A., King, P., Korsch, W., LeRose, J., Lindgren, R., Lu, H. -J., Luo, W., Marcucci, L. E., Markowitz, P., Meziane, M., Michaels, R., Moffit, B., Monaghan, P., Muangma, N., Nanda, S., Norum, B. E., Pan, K., Parno, D. S., Piasetzky, E., Posik, M., Punjabi, V., Puckett, A. J. R., Qian, X., Qiang, Y., Qui, X., Riordan, S., Saha, A., Sauer, P. U., Sawatzky, B., Schiavilla, R., Schoenrock, B., Shabestari, M., Shahinyan, A., Širca, S., Skibiński, R., John, J. St., Subedi, R., Sulkosky, V., Tireman, W., Tobias, W. A., Topolnicki, K., Urciuoli, G. M., Viviani, M., Wang, D., Wang, K., Wang, Y., Watson, J., Wojtsekhowski, B., Witała, H., Ye, Z., Zhan, X., Zhang, Y., Zheng, X., Zhao, B., Zhu, L., and Collaboration, The Jefferson Lab Hall A
Subjects: Nuclear Experiment
Abstract: We report on a precise measurement of double-polarization asymmetries in electron-induced breakup of $^3\mathrm{He}$ proceeding to $\mathrm{pd}$ and $\mathrm{ppn}$ final states, performed in quasi-elastic kinematics at $Q^2 = 0.25\,(\mathrm{GeV}/c)^2$ for missing momenta up to $250\,\mathrm{MeV}/c$. These observables represent highly sensitive tools to investigate the electromagnetic and spin structure of $^3\mathrm{He}$ and the relative importance of two- and three-body effects involved in the breakup reaction dynamics. The measured asymmetries cannot be satisfactorily reproduced by state-of-the-art calculations of $^3\mathrm{He}$ unless their three-body segment is adjusted, indicating that the spin-dependent part of the nuclear interaction governing the three-body breakup process is much smaller than previously thought., Comment: 5 pages, 3 figures, submitted to Phys. Rev. Lett
Published: 2018
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36. Comparing proton momentum distributions in A = 2 and 3 nuclei via 2H 3H and 3He (e,e′p) measurements

Author: Cruz-Torres, R, Li, S, Hauenstein, F, Schmidt, A, Nguyen, D, Abrams, D, Albataineh, H, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Ayerbe Gayoso, C, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, JP, Cohen, EO, Covrig, S, Craycraft, K, Dongwi, B, Duer, M, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, O, Hattawy, M, Hen, O, Higinbotham, DW, Hughes, E, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Karki, A, Karki, B, Katramatou, AT, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, King, D, King, P, Korover, I, Kutz, T, Lashley-Colthirst, N, Laskaris, G, Li, W, Liu, H, Liyanage, N, Lonardoni, D, Machleidt, R, Marcucci, LE, Markowitz, P, McClellan, RE, Meekins, D, Mey-Tal Beck, S, Meziani, ZE, Michaels, R, Mihovilovič, M, Nelyubin, V, Nuruzzaman, N, Nycz, M, Obrecht, R, Olson, M, Ou, L, Owen, V, Pandey, B, Pandey, V, Papadopoulou, A, Park, S, Patsyuk, M, Paul, S, Petratos, GG, Piasetzky, E, Pomatsalyuk, R, Premathilake, S, Puckett, AJR, and Punjabi, V
Subjects: nucl-ex, nucl-th, Nuclear & Particles Physics, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract: We report the first measurement of the (e,e′p) reaction cross-section ratios for Helium-3 (He3), Tritium (H3), and Deuterium (d). The measurement covered a missing momentum range of 40≤pmiss≤550MeV/c, at large momentum transfer (〈Q2〉≈1.9 (GeV/c)2) and xB>1, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for He3/d and H3/d extend to just above the typical nucleon Fermi-momentum (kF≈250 MeV/c) and differ from each other by ∼20%, while for He3/H3 they agree within the measurement accuracy of about 3%. At momenta above kF, the measured He3/H3 ratios differ from the calculation by 20%−50%. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the He3/H3 cross-section ratio for this measurement by less than 5%. If these calculations are correct, then the differences at large missing momenta between the He3/H3 experimental and calculated ratios could be due to the underlying NN interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the NN interaction.
Published: 2019

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

Author: Collaboration, Jefferson Lab Hall A Tritium, Cruz-Torres, R, Li, S, Hauenstein, F, Schmidt, A, Nguyen, D, Abrams, D, Albataineh, H, Alsalmi, S, Androic, D, Aniol, K, Armstrong, W, Arrington, J, Atac, H, Averett, T, Gayoso, C Ayerbe, Bai, X, Bane, J, Barcus, S, Beck, A, Bellini, V, Bhatt, H, Bhetuwal, D, Biswas, D, Blyth, D, Boeglin, W, Bulumulla, D, Camsonne, A, Castellanos, J, Chen, J-P, Cohen, EO, Covrig, S, Craycraft, K, Dongwi, B, Duer, M, Duran, B, Dutta, D, Fuchey, E, Gal, C, Gautam, TN, Gilad, S, Gnanvo, K, Gogami, T, Gomez, J, Gu, C, Habarakada, A, Hague, T, Hansen, O, Hattawy, M, Hen, O, Higinbotham, DW, Hughes, E, Hyde, C, Ibrahim, H, Jian, S, Joosten, S, Karki, A, Karki, B, Katramatou, AT, Keppel, C, Khachatryan, M, Khachatryan, V, Khanal, A, King, D, King, P, Korover, I, Kutz, T, Lashley-Colthirst, N, Laskaris, G, Li, W, Liu, H, Liyanage, N, Lonardoni, D, Machleidt, R, Marcucci, LE, Markowitz, P, McClellan, RE, Meekins, D, Beck, S Mey-Tal, Meziani, Z-E, Michaels, R, Mihovilovič, M, Nelyubin, V, Nuruzzaman, N, Nycz, M, Obrecht, R, Olson, M, Ou, L, Owen, V, Pandey, B, Pandey, V, Papadopoulou, A, Park, S, Patsyuk, M, Paul, S, Petratos, GG, Piasetzky, E, Pomatsalyuk, R, Premathilake, S, and Puckett, AJR
Subjects: Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, nucl-ex, nucl-th, Mathematical Physics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Mathematical sciences, Physical sciences
Abstract: We report the first measurement of the (e,e′p) reaction cross-section ratios for Helium-3 (He3), Tritium (H3), and Deuterium (d). The measurement covered a missing momentum range of 40≤pmiss≤550MeV/c, at large momentum transfer (〈Q2〉≈1.9 (GeV/c)2) and xB>1, which minimized contributions from non quasi-elastic (QE) reaction mechanisms. The data is compared with plane-wave impulse approximation (PWIA) calculations using realistic spectral functions and momentum distributions. The measured and PWIA-calculated cross-section ratios for He3/d and H3/d extend to just above the typical nucleon Fermi-momentum (kF≈250 MeV/c) and differ from each other by ∼20%, while for He3/H3 they agree within the measurement accuracy of about 3%. At momenta above kF, the measured He3/H3 ratios differ from the calculation by 20%−50%. Final state interaction (FSI) calculations using the generalized Eikonal Approximation indicate that FSI should change the He3/H3 cross-section ratio for this measurement by less than 5%. If these calculations are correct, then the differences at large missing momenta between the He3/H3 experimental and calculated ratios could be due to the underlying NN interaction, and thus could provide new constraints on the previously loosely-constrained short-distance parts of the NN interaction.
Published: 2019

38. A Glimpse of Gluons through Deeply Virtual Compton Scattering on the Proton

Author: Defurne, M., Jiménez-Argüello, A. Martì, Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Hyde, C. E., Iqbal, S., Itard, F., Kang, H., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Mazouz, M., Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatié, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Experiment
Abstract: The proton is composed of quarks and gluons, bound by the most elusive mechanism of strong interaction called confinement. In this work, the dynamics of quarks and gluons are investigated using deeply virtual Compton scattering (DVCS): produced by a multi-GeV electron, a highly virtual photon scatters off the proton which subsequently radiates a high energy photon. Similarly to holography, measuring not only the magnitude but also the phase of the DVCS amplitude allows to perform 3D images of the internal structure of the proton. The phase is made accessible through the quantum-mechanical interference of DVCS with the Bethe-Heitler (BH) process, in which the final photon is emitted by the electron rather than the proton. We report herein the first full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the high energy regime where the scattering process is expected to occur off a single quark in the proton, these accurate measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.
Published: 2017
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39. Rosenbluth separation of the $\pi^0$ Electroproduction Cross Section off the Neutron

Author: Mazouz, M., Ahmed, Z., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., Defurne, M., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Huber, G. M., Hyde, C. E., Iqbal, S., Itard, F., Kang, Ho., Kang, Hy., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jiménez-Argüello, A. Martí, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Muangma, N., Camacho, C. Muñoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabatié, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zana, L., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report the first longitudinal/transverse separation of the deeply virtual exclusive $\pi^0$ electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions $d\sigma_L/dt$, $d\sigma_T/dt$, $d\sigma_{LT}/dt$ and $d\sigma_{TT}/dt$ are extracted as a function of the momentum transfer to the recoil system at $Q^2$=1.75 GeV$^2$ and $x_B$=0.36. The $ed \to ed\pi^0$ cross sections are found compatible with the small values expected from theoretical models. The $en \to en\pi^0$ cross sections show a dominance from the response to transversely polarized photons, and are in good agreement with calculations based on the transversity GPDs of the nucleon. By combining these results with previous measurements of $\pi^0$ electroproduction off the proton, we present a flavor decomposition of the $u$ and $d$ quark contributions to the cross section., Comment: 6 pages, 6 figures, Submitted to Phys. Rev. Lett
Published: 2017
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40. Design and expected performance of the MICE demonstration of ionization cooling

Author: MICE Collaboration, Bogomilov, M., Tsenov, R., Vankova-Kirilova, G., Song, Y., Tang, J., Li, Z., Bertoni, R., Bonesini, M., Chignoli, F., Mazza, R., Palladino, V., de Bari, A., Cecchet, G., Orestano, D., Tortora, L., Kuno, Y., Ishimoto, S., Filthaut, F., Jokovic, D., Maletic, D., Savic, M., Hansen, O. M., Ramberger, S., Vretenar, M., Asfandiyarov, R., Blondel, A., Drielsma, F., Karadzhov, Y., Charnley, G., Collomb, N., Gallagher, A., Grant, A., Griffiths, S., Hartnett, T., Martlew, B., Moss, A., Muir, A., Mullacrane, I., Oates, A., Owens, P., Stokes, G., Tucker, M., Warburton, P., White, C., Adams, D., Anderson, R. J., Barclay, P., Bayliss, V., Boehm, J., Bradshaw, T. W., Courthold, M., Dumbell, K., Francis, V., Fry, L., Hayler, T., Hills, M., Lintern, A., Macwaters, C., Nichols, A., Preece, R., Ricciardi, S., Rogers, C., Stanley, T., Tarrant, J., Wilson, A., Watson, S., Bayes, R., Nugent, J. C., Soler, F. J. P., Gamet, R., Barber, G., Blackmore, V. J., Colling, D., Dobbs, A., Dornan, P., Hunt, C., Kurup, A., Lagrange, J-B., Long, K., Martyniak, J., Middleton, S., Pasternak, J., Uchida, M. A., Cobb, J. H., Lau, W., Booth, C. N., Hodgson, P., Langlands, J., Overton, E., Robinson, M., Smith, P. J., Wilbur, S., Dick, A. J., Ronald, K., Whyte, C. G., Young, A. R., Boyd, S., Franchini, P., Greis, J. R., Pidcott, C., Taylor, I., Gardener, R. B. S., Kyberd, P., Nebrensky, J. J., Palmer, M., Witte, H., Bross, A. D., Bowring, D., Liu, A., Neuffer, D., Popovic, M., Rubinov, P., DeMello, A., Gourlay, S., Li, D., Prestemon, S., Virostek, S., Freemire, B., Hanlet, P., Kaplan, D. M., Mohayai, T. A., Rajaram, D., Snopok, P., Suezaki, V., Torun, Y., Onel, Y., Cremaldi, L. M., Sanders, D. A., Summers, D. J., Hanson, G. G., and Heidt, C.
Subjects: Physics - Accelerator Physics
Abstract: Muon beams of low emittance provide the basis for the intense, well-characterised neutrino beams necessary to elucidate the physics of flavour at a neutrino factory and to provide lepton-antilepton collisions at energies of up to several TeV at a muon collider. The international Muon Ionization Cooling Experiment (MICE) aims to demonstrate ionization cooling, the technique by which it is proposed to reduce the phase-space volume occupied by the muon beam at such facilities. In an ionization-cooling channel, the muon beam passes through a material in which it loses energy. The energy lost is then replaced using RF cavities. The combined effect of energy loss and re-acceleration is to reduce the transverse emittance of the beam (transverse cooling). A major revision of the scope of the project was carried out over the summer of 2014. The revised experiment can deliver a demonstration of ionization cooling. The design of the cooling demonstration experiment will be described together with its predicted cooling performance., Comment: 21 pages, 10 figures
Published: 2017
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41. A System of Connected Digital Twins with Artificial Intelligent Solutions - The Key to Resolving the Energy Trilemma

Author: Hansen, O. H., additional, Jaiswal, V., additional, and Eriksson, K., additional
Published: 2024
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42. A Trustworthy Digital Twin for Data Driven Verification

Author: Hansen, O. H., additional, Stang, J., additional, and Jaiswal, V., additional
Published: 2024
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43. 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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44. A Search for the LHCb Charmed 'Pentaquark' using Photo-Production of $J/{\psi}$ at Threshold in Hall C at Jefferson Lab

Author: Meziani, Z. -E., Joosten, S., Paolone, M., Chudakov, E., Jones, M., Adhikari, K., Aniol, K., Armstrong, W., Arrington, J., Asaturyan, A., Atac, H., Bae, S., Bhatt, H., Bhetuwal, D., Chen, J. -P., Chen, X., Choi, H., Choi, S., Diefenthaler, M., Dunne, J., Dupré, R., Duran, B., Dutta, D., El-Fassi, L., Fu, Q., Gao, H., Go, H., Gu, C., Ha, J., Hafidi, K., Hansen, O., Hattawy, M., Higinbotham, D., Huber, G. M., Markowitz, P., Meekins, D., Mkrtchyan, H., Nouicer, R., Li, W., Li, X., Liu, T., Peng, C., Pentchev, L., Pooser, E., Rehfuss, M., Sparveris, N., Tadevosyan, V., Wang, R., Wesselmann, F. R., Wood, S., Xiong, W., Yan, X., Ye, L., Ye, Z., Zafar, A., Zhang, Y., Zhao, F., Zhao, Z., and Zhamkochyana, S.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We propose to measure the photo-production cross section of $J/{\psi}$ near threshold, in search of the recently observed LHCb hidden-charm resonances $P_c$(4380) and $P_c$(4450) consistent with 'pentaquarks'. The observation of these resonances in photo-production will provide strong evidence of the true resonance nature of the LHCb states, distinguishing them from kinematic enhancements. A bremsstrahlung photon beam produced with an 11 GeV electron beam at CEBAF covers the energy range of $J/{\psi}$ production from the threshold photo-production energy of 8.2 GeV, to an energy beyond the presumed $P_c$(4450) resonance. The experiment will be carried out in Hall C at Jefferson Lab using a 50{\mu}A electron beam incident on a 9% copper radiator. The resulting photon beam passes through a 15 cm liquid hydrogen target, producing $J/{\psi}$ mesons through a diffractive process in the $t$-channel, or through a resonant process in the $s$- and $u$-channel. The decay $e^+e^-$ pair of the $J/{\psi}$ will be detected in coincidence using the two high-momentum spectrometers of Hall C. The spectrometer settings have been optimized to distinguish the resonant $s$- and $u$-channel production from the diffractive $t$-channel $J/{\psi}$ production. The $s$- and $u$-channel production of the charmed 5-quark resonance dominates the $t$-distribution at large $t$. The momentum and angular resolution of the spectrometers is sufficient to observe a clear resonance enhancement in the total cross section and $t$-distribution. We request a total of 11 days of beam time with 9 days to carry the main experiment and 2 days to acquire the needed $t$-channel elastic $J/{\psi}$ production data for a calibration measurement. This calibration measurement in itself will greatly enhance our knowledge of $t$-channel elastic $J/{\psi}$ production near threshold., Comment: This document is an updated version of the original proposal PR12-16-007, which was approved with an 'A' rating and a 'high-impact' label by the Jefferson Lab PAC 44 in July 2016. The experiment was awarded 11 days of beam time
Published: 2016

45. Rosenbluth separation of the $\pi^0$ electroproduction cross section

Author: Defurne, M., Mazouz, M., Albataineh, H., Allada, K., Aniol, K. A., Bellini, V., Benali, M., Boeglin, W., Bertin, P., Brossard, M., Camsonne, A., Canan, M., Chandavar, S., Chen, C., Chen, J. -P., de Jager, C. W., de Leo, R., Desnault, C., Deur, A., Fassi, L. El, Ent, R., Flay, D., Friend, M., Fuchey, E., Frullani, S., Garibaldi, F., Gaskell, D., Giusa, A., Glamazdin, O., Golge, S., Gomez, J., Hansen, O., Higinbotham, D., Holmstrom, T., Horn, T., Huang, J., Huang, M., Hyde, C. E., Iqbal, S., Itard, F., Kang, H., Kelleher, A., Keppel, C., Koirala, S., Korover, I., LeRose, J. J., Lindgren, R., Long, E., Magne, M., Mammei, J., Margaziotis, D. J., Markowitz, P., Jimenez-Arguello, A. Marti, Meddi, F., Meekins, D., Michaels, R., Mihovilovic, M., Camacho, C. Munoz, Nadel-Turonski, P., Nuruzzaman, N., Paremuzyan, R., Puckett, A., Punjabi, V., Qiang, Y., Rakhman, A., Rashad, M. N. H., Riordan, S., Roche, J., Russo, G., Sabati, F., Saenboonruang, K., Saha, A., Sawatzky, B., Selvy, L., Shahinyan, A., Sirca, S., Solvignon, P., Sperduto, M. L., Subedi, R., Sulkosky, V., Sutera, C., Tobias, W. A., Urciuoli, G. M., Wang, D., Wojtsekhowski, B., Yao, H., Ye, Z., Zafar, A., Zhan, X., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We present deeply virtual $\pi^0$ electroproduction cross-section measurements at $x_B$=0.36 and three different $Q^2$--values ranging from 1.5 to 2 GeV$^2$, obtained from experiment E07-007 that ran in the Hall A at Jefferson Lab. The Rosenbluth technique was used to separate the longitudinal and transverse responses. Results demonstrate that the cross section is dominated by its transverse component, and thus is far from the asymptotic limit predicted by perturbative Quantum Chromodynamics. An indication of a non-zero longitudinal contribution is provided by the interference term $\sigma_{LT}$ also measured. Results are compared with several models based on the leading twist approach of Generalized Parton Distributions (GPDs). In particular, a fair agreement is obtained with models where the scattering amplitude is described by a convolution of chiral-odd (transversity) GPDs of the nucleon with the twist-3 pion distribution amplitude. Therefore, neutral pion electroproduction may offer the exciting possibility of accessing transversity GPDs through experiment., Comment: Submitted to Physical Review Letters
Published: 2016
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46. Measurements of $d_{2}^{n}$ and $A_{1}^{n}$: Probing the neutron spin structure

Author: Flay, D., Posik, M., Parno, D. S., Allada, K., Armstrong, W., Averett, T., Benmokhtar, F., Bertozzi, W., Camsonne, A., Canan, M., Cates, G. D., Chen, C., Chen, J. -P., Choi, S., Chudakov, E., Cusanno, F., Dalton, M. M., Deconinck, W., de Jager, C. W., Deng, X., Deur, A., Dutta, C., Fassi, L. El, Franklin, G. B., Friend, M., Gao, H., Garibaldi, F., Gilad, S., Gilman, R., Glamazdin, O., Golge, S., Gomez, J., Guo, L., Hansen, O., Higinbotham, D. W., Holmstrom, T., Huang, J., Hyde, C., Ibrahim, H. F., Jiang, X., Jin, G., Katich, J., Kelleher, A., Kolarkar, A., Korsch, W., Kumbartzki, G., LeRose, J. J., Lindgren, R., Liyanage, N., Long, E., Lukhanin, A., Mamyan, V., McNulty, D., Meziani, Z. -E., Michaels, R., Mihovilovič, M., Moffit, B., Muangma, N., Nanda, S., Narayan, A., Nelyubin, V., Norum, B., Oh, Y., Peng, J. C., Qian, X., Qiang, Y., Rakhman, A., Riordan, S., Saha, A., Sawatzky, B., Shabestari, M. H., Shahinyan, A., Širca, S., Solvignon, P., Subedi, R., Sulkosky, V., Tobias, A., Troth, W., Wang, D., Wang, Y., Wojtsekhowski, B., Yan, X., Yao, H., Ye, Y., Ye, Z., Yuan, L., Zhan, X., Zhang, Y., Zhang, Y. -W., Zhao, B., and Zheng, X.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: We report on the results of the E06-014 experiment performed at Jefferson Lab in Hall A, where a precision measurement of the twist-3 matrix element $d_2$ of the neutron ($d_{2}^{n}$) was conducted. This quantity represents the average color Lorentz force a struck quark experiences in a deep inelastic electron scattering event off a neutron due to its interaction with the hadronizing remnants. This color force was determined from a linear combination of the third moments of the spin structure functions $g_1$ and $g_2$ on $^{3}$He after nuclear corrections had been applied to these moments. The kinematics included two average $Q^{2}$ bins of $3.2$ GeV$^{2}$ and $4.3$ GeV$^{2}$, and Bjorken-$x$ $0.25 \leq x \leq 0.90$ covering the DIS and resonance regions. We found $d_2^n$ to be small and negative for $ = 3.2$ GeV$^{2}$, and smaller for $ = 4.3$ GeV$^{2}$, consistent with a lattice QCD calculation. The twist-4 matrix element $f_{2}^{n}$ was extracted by combining our $d_{2}^{n}$ with the world data on $\Gamma_{1}^{n} = \int_{0}^{1} g_{1}^{n} dx$. We found $f_{2}^{n}$ to be roughly an order of magnitude larger than $d_{2}^{n}$. Utilizing the extracted $d_{2}^{n}$ and $f_{2}^{n}$ data, we separated the color force into its electric and magnetic components, $F_{E}^{y,n}$ and $F_{B}^{y,n}$, and found them to be equal and opposite in magnitude, in agreement with instanton model predictions but not with those from QCD sum rules. Additionally, we have extracted the neutron virtual photon-nucleon asymmetry $A_{1}^{n}$, the structure function ratio $g_{1}^{n}/F_{1}^{n}$, and the quark ratios $(\Delta u + \Delta \bar{u})/(u + \bar{u})$ and $(\Delta d + \Delta \bar{d})/(d + \bar{d})$. These results were found to be consistent with DIS world data and with the prediction of the constituent quark model but at odds with those of perturbative QCD at large $x$., Comment: 55 Pages, 45 figures, 48 tables. 15 supplemental files. Grammatical and typo fixes. Revised some model descriptions and updated analyses for f_2^n and color forces
Published: 2016
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47. Pion contamination in the MICE muon beam

Author: Adams, D., Alekou, A., Apollonio, M., Asfandiyarov, R., Barber, G., Barclay, P., de Bari, A., Bayes, R., Bayliss, V., Bertoni, R., Blackmore, V. J., Blondel, A., Blot, S., Bogomilov, M., Bonesini, M., Booth, C. N., Bowring, D., Boyd, S., Bradshaw, T. W., Bravar, U., Bross, A. D., Capponi, M., Carlisle, T., Cecchet, G., Charnley, C., Chignoli, F., Cline, D., Cobb, J. H., Colling, G., Collomb, N., Coney, L., Cooke, P., Courthold, M., Cremaldi, L. M., DeMello, A., Dick, A., Dobbs, A., Dornan, P., Drews, M., Drielsma, F., Filthaut, F., Fitzpatrick, T., Franchini, P., Francis, V., Fry, L., Gallagher, A., Gamet, R., Gardener, R., Gourlay, S., Grant, A., Greis, J. R., Griffiths, S., Hanlet, P., Hansen, O. M., Hanson, G. G., Hart, T. L., Hartnett, T., Hayler, T., Heidt, C., Hills, M., Hodgson, P., Hunt, C., Iaciofano, A., Ishimoto, S., Kafka, G., Kaplan, D. M., Karadzhov, Y., Kim, Y. K., Kuno, Y., Kyberd, P., Lagrange, J-B, Langlands, J., Lau, W., Leonova, M., Li, D., Lintern, A., Littlefield, M., Long, K., Luo, T., Macwaters, C., Martlew, B., Martyniak, J., Mazza, R., Middleton, S., Moretti, A., Moss, A., Muir, A., Mullacrane, I., Nebrensky, J. J., Neuffer, D., Nichols, A., Nicholson, R., Nugent, J. C., Oates, A., Onel, Y., Orestano, D., Overton, E., Owens, P., Palladino, V., Pasternak, J., Pastore, F., Pidcott, C., Popovic, M., Preece, R., Prestemon, S., Rajaram, D., Ramberger, S., Rayner, M. A., Ricciardi, S., Roberts, T. J., Robinson, M., Rogers, C., Ronald, K., Rubinov, P., Rucinski, P., Sakamato, H., Sanders, D. A., Santos, E., Savidge, T., Smith, P. J., Snopok, P., Soler, F. J. P., Speirs, D., Stanley, T., Stokes, G., Summers, D. J., Tarrant, J., Taylor, I., Tortora, L., Torun, Y., Tsenov, R., Tunnell, C. D., Uchida, M. A., Vankova-Kirilova, G., Virostek, S., Vretenar, M., Warburton, P., Watson, S., White, C., Whyte, C. G., Wilson, A., Winter, M., Yang, X., Young, A., and Zisman, M.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: The international Muon Ionization Cooling Experiment (MICE) will perform a systematic investigation of ionization cooling with muon beams of momentum between 140 and 240\,MeV/c at the Rutherford Appleton Laboratory ISIS facility. The measurement of ionization cooling in MICE relies on the selection of a pure sample of muons that traverse the experiment. To make this selection, the MICE Muon Beam is designed to deliver a beam of muons with less than $\sim$1\% contamination. To make the final muon selection, MICE employs a particle-identification (PID) system upstream and downstream of the cooling cell. The PID system includes time-of-flight hodoscopes, threshold-Cherenkov counters and calorimetry. The upper limit for the pion contamination measured in this paper is $f_\pi < 1.4\%$ at 90\% C.L., including systematic uncertainties. Therefore, the MICE Muon Beam is able to meet the stringent pion-contamination requirements of the study of ionization cooling., Comment: 16 pages, 7 figures
Published: 2015
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48. Electron-Muon Ranger: performance in the MICE Muon Beam

Author: Adams, D., Alekou, A., Apollonio, M., Asfandiyarov, R., Barber, G., Barclay, P., de Bari, A., Bayes, R., Bayliss, V., Bene, P., Bertoni, R., Blackmore, V. J., Blondel, A., Blot, S., Bogomilov, M., Bonesini, M., Booth, C. N., Bowring, D., Boyd, S., Bradshaw, T. W., Bravar, U., Bross, A. D., Cadoux, F., Capponi, M., Carlisle, T., Cecchet, G., Charnley, C., Chignoli, F., Cline, D., Cobb, J. H., Colling, G., Collomb, N., Coney, L., Cooke, P., Courthold, M., Cremaldi, L. M., Debieux, S., DeMello, A., Dick, A., Dobbs, A., Dornan, P., Drielsma, F., Filthaut, F., Fitzpatrick, T., Franchini, P., Francis, V., Fry, L., Gallagher, A., Gamet, R., Gardener, R., Gourlay, S., Grant, A., Graulich, J. S., Greis, J., Griffiths, S., Hanlet, P., Hansen, O. M., Hanson, G. G., Hart, T. L., Hartnett, T., Hayler, T., Heidt, C., Hills, M., Hodgson, P., Hunt, C., Husi, C., Iaciofano, A., Ishimoto, S., Kafka, G., Kaplan, D. M., Karadzhov, Y., Kim, Y. K., Kuno, Y., Kyberd, P., Lagrange, J-B, Langlands, J., Lau, W., Leonova, M., Li, D., Lintern, A., Littlefield, M., Long, K., Luo, T., Macwaters, C., Martlew, B., Martyniak, J., Masciocchi, F., Mazza, R., Middleton, S., Moretti, A., Moss, A., Muir, A., Mullacrane, I., Nebrensky, J. J., Neuffer, D., Nichols, A., Nicholson, R., Nicola, L., Messomo, E. Noah, Nugent, J. C., Oates, A., Onel, Y., Orestano, D., Overton, E., Owens, P., Palladino, V., Pasternak, J., Pastore, F., Pidcott, C., Popovic, M., Preece, R., Prestemon, S., Rajaram, D., Ramberger, S., Rayner, M. A., Ricciardi, S., Roberts, T. J., Robinson, M., Rogers, C., Ronald, K., Rothenfusser, K., Rubinov, P., Rucinski, P., Sakamato, H., Sanders, D. A., Sandstrom, R., Santos, E., Savidge, T., Smith, P. J., Snopok, P., Soler, F. J. P., Speirs, D., Stanley, T., Stokes, G., Summers, D. J., Tarrant, J., Taylor, I., Tortora, L., Torun, Y., Tsenov, R., Tunnell, C. D., Uchida, M. A., Vankova-Kirilova, G., Virostek, S., Vretenar, M., Warburton, P., Watson, S., White, C., Whyte, C. G., Wilson, A., Wisting, H., Yang, X., Young, A., and Zisman, M.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: The Muon Ionization Cooling Experiment (MICE) will perform a detailed study of ionization cooling to evaluate the feasibility of the technique. To carry out this program, MICE requires an efficient particle-identification (PID) system to identify muons. The Electron-Muon Ranger (EMR) is a fully-active tracking-calorimeter that forms part of the PID system and tags muons that traverse the cooling channel without decaying. The detector is capable of identifying electrons with an efficiency of 98.6%, providing a purity for the MICE beam that exceeds 99.8%. The EMR also proved to be a powerful tool for the reconstruction of muon momenta in the range 100-280 MeV/$c$., Comment: 22 pages, 19 figures
Published: 2015
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49. Electroexcitation of the $\Delta^{+}(1232)$ at low momentum transfer

Author: Blomberg, A., Anez, D., Sparveris, N., Sarty, A., Paolone, M., Gilad, S., Higinbotham, D., Abudureyimu, A. R., Ahmed, Z., Albataineh, H., Allada, K., Anderson, B., Aniol, K., Annand, J., Averett, T., Baghdasaryan, H., Bai, X., Beck, A., Beck, S., Bellini, V., Benmokhtar, F., Boeglin, W., Camacho, C. M., Camsonne, A., Chen, C., Chen, J. P., Chirapatpimol, K., Cisbani, E., Dalton, M., Deconinck, W., Defurne, M., De Leo, R., Flay, D., Fomin, N., Friend, M., Frullani, S., Fuchey, E., Garibaldi, F., Gilman, R., Gu, C., Hamilton, D., Hanretty, C., Hansen, O., Shabestari, M. Hashemi, Holmstrom, T., Huang, M., Iqbal, S., Kalantarians, N., Kang, H., Kelleher, A., Khandaker, M., Leckey, J., LeRose, J., Lindgren, R., Long, E., Mammei, J., Margaziotis, D. J., Jimenez-Arguello, A. Marti, Meziani, Z. E., Mihovilovic, M., Muangma, N., Norum, B., Nuruzzaman, Pan, K., Phillips, S., Polychronopoulou, A., Pomerantz, I., Posik, M., Punjabi, V., Qian, X., Reimer, P. E., Riordan, S., Ron, G., Saha, A., Schulte, E., Selvy, L., Sirca, S., Sjoegren, J., Subedi, R., Sulkosky, V., Tireman, W., Wang, D., Watson, J., Weinstein, L., Wojtsekhowski, B., Yan, W., Yaron, I., Ye, Z., Zhan, X., Zhang, Y., Zhang, J., Zhao, B., Zhao, Z., Zheng, X., and Zhu, P.
Subjects: Nuclear Experiment
Abstract: We report on new p$(e,e^\prime p)\pi^\circ$ measurements at the $\Delta^{+}(1232)$ resonance at the low momentum transfer region. The mesonic cloud dynamics is predicted to be dominant and rapidly changing in this kinematic region offering a test bed for chiral effective field theory calculations. The new data explore the low $Q^2$ dependence of the resonant quadrupole amplitudes while extending the measurements of the Coulomb quadrupole amplitude to the lowest momentum transfer ever reached. The results disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The reported measurements suggest that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements.
Published: 2015
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50. The E00-110 experiment in Jefferson Lab's Hall A: Deeply Virtual Compton Scattering off the Proton at 6 GeV

Author: Defurne, M., Amaryan, M., Aniol, K. A., Beaumel, M., Benaoum, H., Bertin, P., Brossard, M., Camsonne, A., Chen, J. -P., Chudakov, E., Craver, B., Cusanno, F., de Jager, C. W., Deur, A., Feuerbach, R., Ferdi, C., Fieschi, J. -M., Frullani, S., Fuchey, E., Garcon, M., Garibaldi, F., Gayou, O., Gavalian, G., Gilman, R., Gomez, J., Gueye, P., Guichon, P. A. M., Guillon, B., Hansen, O., Hayes, D., Higinbotham, D., Holmstrom, T., Hyde, C. E., Ibrahim, H., Igarashi, R., Jiang, X., Jo, H. S., Kaufman, L. J., Kelleher, A., Keppel, C., Kolarkar, A., Kuchina, E., Kumbartzki, G., Laveissière, G., LeRose, J. J., Lindgren, R., Liyanage, N., Lu, H. -J., Margaziotis, D. J., Mazouz, M., Meziani, Z. -E., McCormick, K., Michaels, R., Michel, B., Moffit, B., Monaghan, P., Camacho, C. Muñoz, Nanda, S., Nelyubin, V., Paremuzyan, R., Potokar, M., Qiang, Y., Ransome, R. D., Réal, J. -S., Reitz, B., Roblin, Y., Roche, J., Sabatié, F., Saha, A., Sirca, S., Slifer, K., Solvignon, P., Subedi, R., Sulkosky, V., Ulmer, P. E., Voutier, E., Wang, K., Weinstein, L. B., Wojtsekhowski, B., Zheng, X., and Zhu, L.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We present final results on the photon electroproduction ($\vec{e}p\rightarrow ep\gamma$) cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region from Jefferson Lab experiment E00-110. Results from an analysis of a subset of these data were published before, but the analysis has been improved which is described here at length, together with details on the experimental setup. Furthermore, additional data have been analyzed resulting in photon electroproduction cross sections at new kinematic settings, for a total of 588 experimental bins. Results of the $Q^2$- and $x_B$-dependences of both the helicity-dependent and helicity-independent cross sections are discussed. The $Q^2$-dependence illustrates the dominance of the twist-2 handbag amplitude in the kinematics of the experiment, as previously noted. Thanks to the excellent accuracy of this high luminosity experiment, it becomes clear that the unpolarized cross section shows a significant deviation from the Bethe-Heitler process in our kinematics, compatible with a large contribution from the leading twist-2 DVCS$^2$ term to the photon electroproduction cross section. The necessity to include higher-twist corrections in order to fully reproduce the shape of the data is also discussed. The DVCS cross sections in this paper represent the final set of experimental results from E00-110, superseding the previous publication., Comment: 48 pages, 32 figures
Published: 2015
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