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873 results on '"McKinnon, B."'

1. First Measurement of Deeply Virtual Compton Scattering on the Neutron with Detection of the Active Neutron

Author: CLAS Collaboration, Hobart, A., Niccolai, S., Čuić, M., Kumerički, K., Achenbach, P., Alvarado, J. S., Armstrong, W. R., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boiarinov, S., Bondi, M., Booth, W. A., Bossù, F., Brinkmann, K. -Th., Briscoe, W. J., Brooks, W. K., Bueltmann, S., Burkert, V. D., Cao, T., Capobianco, R., Carman, D. S., Chatagnon, P., Ciullo, G., Cole, P. L., Contalbrigo, M., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Fogler, C., Gates, K., Gavalian, G., Gilfoyle, G. P., Glazier, D., Gothe, R. W., Gotra, Y., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jiang, H., Jo, H. S., Joo, K., Kageya, T., Kim, A., Kim, W., Klimenko, V., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., MacGregor, I. J. D., Marchand, D., Mascagna, V., Maynes, M., McKinnon, B., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Muñoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Rafael, S. Polcher, Poudel, J., Price, J. W., Prok, Y., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Golubenko, A. A., Salgado, C., Schadmand, S., Schmidt, A., Scott, Marshall B. C., Seroka, E. M., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Tommaso, V., Voskanyan, H., Voutier, E., Watts, D. P, Wei, X., Williams, R., Wood, M. H., Xu, L., Zachariou, N., Zhang, J., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Measuring Deeply Virtual Compton Scattering on the neutron is one of the necessary steps to understand the structure of the nucleon in terms of Generalized Parton Distributions (GPDs). Neutron targets play a complementary role to transversely polarized proton targets in the determination of the GPD $E$. This poorly known and poorly constrained GPD is essential to obtain the contribution of the quarks' angular momentum to the spin of the nucleon. DVCS on the neutron was measured for the first time selecting the exclusive final state by detecting the neutron, using the Jefferson Lab longitudinally polarized electron beam, with energies up to 10.6 GeV, and the CLAS12 detector. The extracted beam-spin asymmetries, combined with DVCS observables measured on the proton, allow a clean quark-flavor separation of the imaginary parts of the GPDs $H$ and $E$., Comment: 7 pages, 6 figures
Published: 2024

2. Photoproduction of the {\Sigma}+ hyperon using linearly polarized photons with CLAS

Author: CLAS Collaboration, Clark, L., McKinnon, B., Ireland, D. G., Glazier, D. I., Livingston, K., and Rönchen, D.
Subjects: Nuclear Experiment
Abstract: Background: Measurements of the polarization observables {\Sigma}, P, T, Ox, Oz for the reaction {\gamma}p {\rightarrow) KS0 {\Sigma}+ using a linearly polarized photon beam of energy 1.1 to 2.1 GeV are reported. Purpose: The measured data provide information on a channel that has not been studied extensively, but is required for a full coupled-channel analysis in the nucleon resonance region. Method: Observables have been simultaneously extracted using likelihood sampling with a Markov-Chain Monte- Carlo process. Results: Angular distributions in bins of photon energy E{\gamma} are produced for each polarization observable. T, Ox and Oz are first time measurements of these observables in this reaction. The extraction of {\Sigma} extends the energy range beyond a previous measurement. The measurement of P, the recoil polarization, is consistent with previous measurements. Conclusions: The measured data are shown to be significant enough to affect the estimation of the nucleon resonance parameters when fitted within a coupled-channels model., Comment: 10 pages, 5 figures
Published: 2024

3. Beam Charge Asymmetries for Deeply Virtual Compton Scattering on the Proton at CLAS12

Author: Voutier, E., Burkert, V., Niccolai, S., Paremuzyan, R., Afanasev, A., Alvarado-Galeano, J. -S., Atoui, M., Barion, L., Battaglieri, M., Bernauer, J., Bianconi, A., Bondi, M., Briscoe, W., Camsonne, A., Capobianco, R., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Cole, P., Contalbrigo, M., Costantini, G., Defurne, M., Deur, A., De Vita, R., Diehl, S., Dupré, R., Elouadrhiri, L., Fernando, I., Filippi, A., Forest, T., Girod, F. -X., Gosta, G., Grames, J., Gueye, P., Habet, S., Hattawy, M., Higinbotham, D., Hobart, A., Hyde, C., Joo, K., Kim, A., Klimenko, V., Kubarovsky, V., Leali, M., Lenisa, P., Marchand, D., Marsicano, L., Mascagna, V., Matamoros, D., McCaughan, M., McKinnon, B., Migliorati, S., Mitra, H. S., Movsisyan, A., Muñoz-Camacho, C., Osipenko, M., Ouillon, M., Pappalardo, L., Pasquini, B., Pasyuk, E., Pilleux, N., Poelker, M., Raue, B., Ripani, M., Santos, R., Schmidt, A., Singh, R., Sokhan, D., Spreafico, M., Stoler, P., Strakovsky, I., Taiuti, M., Venturelli, L., Wang, P. -K., Wei, X., Zhao, Z., Collaboration, the CLAS, and Group, the Jefferson Lab Positron Working
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The parameterization of the nucleon structure through Generalized Parton Distributions (GPDs) shed a new light on the nucleon internal dynamics. For its direct interpretation, Deeply Virtual Compton Scattering (DVCS) is the golden channel for GPDs investigation. The DVCS process interferes with the Bethe-Heitler (BH) mechanism to constitute the leading order amplitude of the $eN \to eN\gamma$ process. The study of the $ep\gamma$ reaction with polarized positron and electron beams gives a complete set of unique observables to unravel the different contributions to the $ep \gamma$ cross section. This separates the different reaction amplitudes, providing a direct access to their real and imaginary parts which procures crucial constraints on the model dependences and associated systematic uncertainties on GPDs extraction. The real part of the BH-DVCS interference amplitude is particularly sensitive to the $D$-term which parameterizes the Gravitational Form Factors of the nucleon. The separation of the imaginary parts of the interference and DVCS amplitudes provides insights on possible higher-twist effects. We propose to measure the unpolarized and polarized Beam Charge Asymmetries (BCAs) of the $\vec{e}^{\pm}p \to e^{\pm}p \gamma$ process on an unpolarized hydrogen target with {\tt CLAS12}, using polarized positron and electron beams at 10.6 GeV. The azimuthal and $t$-dependences of the unpolarized and polarized BCAs will be measured over a large $(x_B,Q^2)$ phase space using a 100 day run with a luminosity of 0.66$\times 10^{35}$cm$^{-2}\cdot$s$^{-1}$., Comment: Proposal to the Jefferson Lab Program Advisory Committee (PAC51)
Published: 2023

4. Beam Spin Asymmetry Measurements of Deeply Virtual $\pi^0$ Production with CLAS12

Author: Kim, A., Diehl, S., Joo, K., Kubarovsky, V., Achenbach, P., Akbar, Z., Alvarado, J. S., Armstrong, Whitney R., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Bianconi, A., Biselli, A. S., Bondi, M., Bossù, F., Boiarinov, S., Brinkmann, K. T., Briscoe, W. J., Brooks, W. K., Bueltmann, S., Burkert, V. D., Capobianco, R., Carman, D. S., Carvajal, J. C., Celentano, A., Charles, G., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clary, B., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., DeVita, R., Defurne, M., Deur, A., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., ElAlaoui, A., ElFassi, L., Fegan, S., Filippi, A., Fogler, C., Gavalian, G., Gilfoyle, G. P., Gosta, G., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Hung, Yu-Chun, Ilieva, Y., Ireland, D. G., Isupov, E., Jo, H. S., Johnston, R., Joosten, S., Khachatryan, M., Khanal, A., Kim, W., Klimenko, V., Kripko, A., Kuhn, S. E., Lanza, L., Leali, M., Kabir, M. L., Lee, S., Lenisa, P., Li, X., MacGregor, I . J . D., Marchand, D., Mascagna, V., McKinnon, B., Matamoros, D., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Moran, P., MunozCamacho, C., Naidoo, P., Neupane, K., Nguyen, D., Niccolai, S., Niculescu, G., Osipenko, M., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Radic, A., Ramasubramanian, N., Reed, Trevor, Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sokhan, D., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Wishart, R., Wood, M. H., Yurov, M., Zachariou, N., Zhang, J., Ziegler, V., and Zurek, M.
Subjects: Nuclear Experiment
Abstract: The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive $\pi^0$ production in a wide kinematic region with the photon virtualities $Q^2$ up to 8 GeV$^2$ and the Bjorken scaling variable $x_B$ in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions.The interpretation of these measurements in terms of the Generalized Parton Distributions (GPDs) demonstrates their sensitivity to the chiral-odd GPD $\bar E_T$, which contains information on quark transverse spin densities in unpolarized and polarized nucleons and provides access to the proton's transverse anomalous magnetic moment. Additionally, the data were compared to a theoretical model based on a Regge formalism that was extended to the high photon virtualities., Comment: arXiv admin note: substantial text overlap with arXiv:2210.14557
Published: 2023

5. Strong interaction physics at the luminosity frontier with 22 GeV electrons at Jefferson Lab

Author: Accardi, A., Achenbach, P., Adhikari, D., Afanasev, A., Akondi, C. S., Akopov, N., Albaladejo, M., Albataineh, H., Albrecht, M., Almeida-Zamora, B., Amaryan, M., Androić, D., Armstrong, W., Armstrong, D. S., Arratia, M., Arrington, J., Asaturyan, A., Austregesilo, A., Avakian, H., Averett, T., Gayoso, C. Ayerbe, Bacchetta, A., Balantekin, A. B., Baltzell, N., Barion, L., Barry, P. C., Bashir, A., Battaglieri, M., Bellini, V., Belov, I., Benhar, O., Benkel, B., Benmokhtar, F., Bentz, W., Bertone, V., Bhatt, H., Bianconi, A., Bibrzycki, L., Bijker, R., Binosi, D., Biswas, D., Boër, M., Boeglin, W., Bogacz, S. A., Boglione, M., Bondí, M., Boos, E. E., Bosted, P., Bozzi, G., Brash, E. J., Briceño, R. A., Brindza, P. D., Briscoe, W. J., Brodsky, S. J., Brooks, W. K., Burkert, V. D., Camsonne, A., Cao, T., Cardman, L. S., Carman, D. S., Carpinelli, M., Cates, G. D., Caylor, J., Celentano, A., Celiberto, F. G., Cerutti, M., Chang, L., Chatagnon, P., Chen, C., Chen, J.-P., Chetry, T., Christopher, A., Christy, E., Chudakov, E., Cisbani, E., Cloët, I. C., Cobos-Martinez, J. J., Cohen, E. O., Colangelo, P., Cole, P. L., Constantinou, M., Contalbrigo, M., Costantini, G., Cosyn, W., Cotton, C., Courtoy, A., Dusa, S. Covrig, Crede, V., Cui, Z.-F., D’Angelo, A., Döring, M., Dalton, M. M., Danilkin, I., Davydov, M., Day, D., De Fazio, F., De Napoli, M., De Vita, R., Dean, D. J., Defurne, M., de Paula, W., de Téramond, G. F., Deur, A., Devkota, B., Dhital, S., Di Nezza, P., Diefenthaler, M., Diehl, S., Dilks, C., Ding, M., Djalali, C., Dobbs, S., Dupré, R., Dutta, D., Edwards, R. G., Egiyan, H., Ehinger, L., Eichmann, G., Elaasar, M., Elouadrhiri, L., Alaoui, A. El, Fassi, L. El, Emmert, A., Engelhardt, M., Ent, R., Ernst, D. J., Eugenio, P., Evans, G., Fanelli, C., Fegan, S., Fernández-Ramírez, C., Fernandez, L. A., Fernando, I. P., Filippi, A., Fischer, C. S., Fogler, C., Fomin, N., Frankfurt, L., Frederico, T., Freese, A., Fu, Y., Gamberg, L., Gan, L., Gao, F., Garcia-Tecocoatzi, H., Gaskell, D., Gasparian, A., Gates, K., Gavalian, G., Ghoshal, P. K., Giachino, A., Giacosa, F., Giannuzzi, F., Gilfoyle, G.-P., Girod, F.-X., Glazier, D. I., Gleason, C., Godfrey, S., Goity, J. L., Golubenko, A. A., Gonzàlez-Solís, S., Gothe, R. W., Gotra, Y., Griffioen, K., Grocholski, O., Grube, B., Guèye, P., Guo, F.-K., Guo, Y., Guo, L., Hague, T. J., Hammoud, N., Hansen, J.-O., Hattawy, M., Hauenstein, F., Hayward, T., Heddle, D., Heinrich, N., Hen, O., Higinbotham, D. W., Higuera-Angulo, I. M., Hiller Blin, A. N., Hobart, A., Hobbs, T., Holmberg, D. E., Horn, T., Hoyer, P., Huber, G. M., Hurck, P., Hutauruk, P. T. P., Ilieva, Y., Illari, I., Ireland, D. G., Isupov, E. L., Italiano, A., Jaegle, I., Jarvis, N. S., Jenkins, D. J., Jeschonnek, S., Ji, C.-R., Jo, H. S., Jones, M., Jones, R. T., Jones, D. C., Joo, K., Junaid, M., Kageya, T., Kalantarians, N., Karki, A., Karyan, G., Katramatou, A. T., Kay, S. J. D., Kazimi, R., Keith, C. D., Keppel, C., Kerbizi, A., Khachatryan, V., Khanal, A., Khandaker, M., Kim, A., Kinney, E. R., Kohl, M., Kotzinian, A., Kriesten, B. T., Kubarovsky, V., Kubis, B., Kuhn, S. E., Kumar, V., Kutz, T., Leali, M., Lebed, R. F., Lenisa, P., Leskovec, L., Li, S., Li, X., Liao, J., Lin, H.-W., Liu, L., Liuti, S., Liyanage, N., Lu, Y., MacGregor, I. J. D., Mack, D. J., Maiani, L., Mamo, K. A., Mandaglio, G., Mariani, C., Markowitz, P., Marukyan, H., Mascagna, V., Mathieu, V., Maxwell, J., Mazouz, M., McCaughan, M., McKeown, R. D., McKinnon, B., Meekins, D., Melnitchouk, W., Metz, A., Meyer, C. A., Meziani, Z.-E., Mezrag, C., Michaels, R., Miller, G. A., Mineeva, T., Miramontes, A. S., Mirazita, M., Mizutani, K., Mkrtchyan, A., Mkrtchyan, H., Moffit, B., Mohanmurthy, P., Mokeev, V. I., Monaghan, P., Montaña, G., Montgomery, R., Moretti, A., Chàvez, J. M. Morgado, Mosel, U., Movsisyan, A., Musico, P., Nadeeshani, S. A., Nadolsky, P. M., Nakamura, S. X., Nazeer, J., Nefediev, A. V., Neupane, K., Nguyen, D., Niccolai, S., Niculescu, I., Niculescu, G., Nocera, E. R., Nycz, M., Olness, F. I., Ortega, P. G., Osipenko, M., Pace, E., Pandey, B., Pandey, P., Papandreou, Z., Papavassiliou, J., Pappalardo, L. L., Paredes-Torres, G., Paremuzyan, R., Park, S., Parsamyan, B., Paschke, K. D., Pasquini, B., Passemar, E., Pasyuk, E., Patel, T., Paudel, C., Paul, S. J., Peng, J.-C., Pentchev, L., Perrino, R., Perry, R. J., Peters, K., Petratos, G. G., Phelps, W., Piasetzky, E., Pilloni, A., Pire, B., Pitonyak, D., Pitt, M. L., Polosa, A. D., Pospelov, M., Postuma, A. C., Poudel, J., Preet, L., Prelovsek, S., Price, J. W., Prokudin, A., Puckett, A. J. R., Pybus, J. R., Qin, S.-X., Qiu, J.-W., Radici, M., Rashidi, H., Rathnayake, A. D., Raue, B. A., Reed, T., Reimer, P. E., Reinhold, J., Richard, J.-M., Rinaldi, M., Ringer, F., Ripani, M., Ritman, J., West, J. Rittenhouse, Rivero-Acosta, A., Roberts, C. D., Rodas, A., Rodini, S., Rodríguez-Quintero, J., Rogers, T. C., Rojo, J., Rossi, P., Rossi, G. C., Salmè, G., Santiesteban, S. N., Santopinto, E., Sargsian, M., Sato, N., Schadmand, S., Schmidt, A., Schmidt, S. M., Schnell, G., Schumacher, R. A., Schweitzer, P., Scimemi, I., Scott, K. C., Seay, D. A., Segovia, J., Semenov-Tian-Shansky, K., Seryi, A., Sharda, A. S., Shepherd, M. R., Shirokov, E. V., Shrestha, S., Shrestha, U., Shvedunov, V. I., Signori, A., Slifer, K. J., Smith, W. A., Somov, A., Souder, P., Sparveris, N., Spizzo, F., Spreafico, M., Stepanyan, S., Stevens, J. R., Strakovsky, I. I., Strauch, S., Strikman, M., Su, S., Sumner, B. C. L., Sun, E., Suresh, M., Sutera, C., Swanson, E. S., Szczepaniak, A. P., Sznajder, P., Szumila-Vance, H., Szymanowski, L., Tadepalli, A.-S., Tadevosyan, V., Tamang, B., Tarasov, V. V., Thiel, A., Tong, X.-B., Tyson, R., Ungaro, M., Urciuoli, G. M., Usman, A., Valcarce, A., Vallarino, S., Vaquera-Araujo, C. A., Venturelli, L., Vera, F., Vladimirov, A., Vossen, A., Wagner, J., Wei, X., Weinstein, L. B., Weiss, C., Williams, R., Winney, D., Wojtsekhowski, B., Wood, M. H., Xiao, T., Xu, S.-S., Ye, Z., Yero, C., Yuan, C.-P., Yurov, M., Zachariou, N., Zhang, Z., Zhao, Y., Zhao, Z. W., Zheng, X., Zhou, X., Ziegler, V., and Zihlmann, B.
Published: 2024
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6. Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

Author: Accardi, A., Achenbach, P., Adhikari, D., Afanasev, A., Akondi, C. S., Akopov, N., Albaladejo, M., Albataineh, H., Albrecht, M., Almeida-Zamora, B., Amaryan, M., Androić, D., Armstrong, W., Armstrong, D. S., Arratia, M., Arrington, J., Asaturyan, A., Austregesilo, A., Avagyan, H., Averett, T., Gayoso, C. Ayerbe, Bacchetta, A., Balantekin, A. B., Baltzell, N., Barion, L., Barry, P. C., Bashir, A., Battaglieri, M., Bellini, V., Belov, I., Benhar, O., Benkel, B., Benmokhtar, F, Bentz, W., Bertone, V., Bhatt, H., Bianconi, A., Bibrzycki, L., Bijker, R., Binosi, D., Biswas, D., Boër, M., Boeglin, W., Bogacz, S. A., Boglione, M., Bondí, M., Boos, E. E., Bosted, P., Bozzi, G., Brash, E. J., Briceño, R. A., Brindza, P. D., Briscoe, W. J., Brodsky, S. J, Brooks, W. K., Burkert, V. D., Camsonne, A., Cao, T., Cardman, L. S., Carman, D. S., Carpinelli, M, Cates, G. D., Caylor, J., Celentano, A., Celiberto, F. G., Cerutti, M., Chang, Lei, Chatagnon, P., Chen, C., Chen, J-P, Chetry, T., Christopher, A., Christy, E., Chudakov, E., Cisbani, E., Cloët, I. C., Cobos-Martinez, J. J., Cohen, E. O., Colangelo, P., Cole, P. L., Constantinou, M., Contalbrigo, M., Costantini, G., Cosyn, W., Cotton, C., Courtoy, A., Dusa, S. Covrig, Crede, V., Cui, Z. -F., D'Angelo, A., Döring, M., Dalton, M. M., Danilkin, I., Davydov, M., Day, D., De Fazio, F., De Napoli, M., De Vita, R., Dean, D. J., Defurne, M., Deur, A., Devkota, B., Dhital, S., Di Nezza, P., Diefenthaler, M., Diehl, S., Dilks, C., Ding, M., Djalali, C., Dobbs, S., Dupré, R., Dutta, D., Edwards, R. G., Egiyan, H., Ehinger, L., Eichmann, G., Elaasar, M., Elouadrhiri, L., Alaoui, A. El, Fassi, L. El, Emmert, A., Engelhardt, M., Ent, R., Ernst, D. J, Eugenio, P., Evans, G., Fanelli, C., Fegan, S., Fernández-Ramírez, C., Fernandez, L. A., Fernando, I. P., Filippi, A., Fischer, C. S., Fogler, C., Fomin, N., Frankfurt, L., Frederico, T., Freese, A., Fu, Y., Gamberg, L., Gan, L., Gao, F., Garcia-Tecocoatzi, H., Gaskell, D., Gasparian, A., Gates, K, Gavalian, G., Ghoshal, P. K., Giachino, A., Giacosa, F., Giannuzzi, F., Gilfoyle, G. -P., Girod, F-X, Glazier, D. I., Gleason, C., Godfrey, S., Goity, J. L., Golubenko, A. A., Gonzàlez-Solís, S., Gothe, R. W., Gotra, Y., Griffioen, K., Grocholski, O., Grube, B., Guèye, P., Guo, F. -K., Guo, Y., Guo, L., Hague, T. J., Hammoud, N., Hansen, J. -O., Hattawy, M., Hauenstein, F., Hayward, T., Heddle, D., Heinrich, N., Hen, O., Higinbotham, D. W., Higuera-Angulo, I. M., Blin, A. N. Hiller, Hobart, A., Hobbs, T., Holmberg, D. E, Horn, T., Hoyer, P., Huber, G. M., Hurck, P., Hutauruk, P. T. P., Ilieva, Y., Illari, I., Ireland, D. G, Isupov, E. L., Italiano, A., Jaegle, I., Jarvis, N. S., Jenkins, DJ, Jeschonnek, S., Ji, C-R., Jo, H. S., Jones, M., Jones, R. T., Jones, D. C., Joo, K., Junaid, M., Kageya, T., Kalantarians, N., Karki, A., Karyan, G., Katramatou, A. T., Kay, S. J. D, Kazimi, R., Keith, C. D., Keppel, C., Kerbizi, A., Khachatryan, V., Khanal, A., Khandaker, M., Kim, A., Kinney, E. R., Kohl, M., Kotzinian, A., Kriesten, B. T., Kubarovsky, V., Kubis, B., Kuhn, S. E., Kumar, V., Kutz, T., Leali, M., Lebed, R. F., Lenisa, P., Leskovec, L., Li, S., Li, X., Liao, J., Lin, H. -W., Liu, L., Liuti, S., Liyanage, N., Lu, Y., MacGregor, I. J. D., Mack, D. J., Maiani, L, Mamo, K. A., Mandaglio, G., Mariani, C., Markowitz, P., Marukyan, H., Mascagna, V., Mathieu, V., Maxwell, J., Mazouz, M., McCaughan, M., McKeown, R. D., McKinnon, B., Meekins, D., Melnitchouk, W., Metz, A., Meyer, C. A., Meziani, Z. -E., Mezrag, C., Michaels, R., Miller, G. A., Mineeva, T., Miramontes, A. S., Mirazita, M., Mizutani, K., Mkrtchyan, H., Mkrtchyan, A., Moffit, B., Mohanmurthy, P., Mokeev, V. I., Monaghan, P., Montaña, G., Montgomery, R., Moretti, A., Chàvez, J. M. Morgado, Mosel, U., Movsisyan, A., Musico, P., Nadeeshani, S. A, Nadolsky, P. M., Nakamura, S. X., Nazeer, J., Nefediev, A. V., Neupane, K., Nguyen, D., Niccolai, S., Niculescu, I., Niculescu, G., Nocera, E. R., Nycz, M., Olness, F. I., Ortega, P. G., Osipenko, M., Pace, E., Pandey, B, Pandey, P., Papandreou, Z., Papavassiliou, J., Pappalardo, L. L., Paredes-Torres, G., Paremuzyan, R., Park, S., Parsamyan, B., Paschke, K. D., Pasquini, B., Passemar, E., Pasyuk, E., Patel, T., Paudel, C., Paul, S. J., Peng, J-C., Pentchev, L., Perrino, R., Perry, R. J., Peters, K., Petratos, G. G., Phelps, W., Piasetzky, E., Pilloni, A., Pire, B., Pitonyak, D., Pitt, M. L., Polosa, A. D., Pospelov, M., Postuma, A. C., Poudel, J., Preet, L., Prelovsek, S., Price, J. W., Prokudin, A., Puckett, A. J. R., Pybus, J. R., Qin, S. -X., Qiu, J. -W., Radici, M., Rashidi, H., Rathnayake, A. D, Raue, B. A., Reed, T., Reimer, P. E., Reinhold, J., Richard, J. -M., Rinaldi, M., Ringer, F., Ripani, M., Ritman, J., West, J. Rittenhouse, Rivero-Acosta, A., Roberts, C. D., Rodas, A., Rodini, S., Rodríguez-Quintero, J., Rogers, T. C., Rojo, J., Rossi, P., Rossi, G. C., Salmè, G., Santiesteban, S. N., Santopinto, E., Sargsian, M., Sato, N., Schadmand, S., Schmidt, A., Schmidt, S. M, Schnell, G., Schumacher, R. A., Schweitzer, P., Scimemi, I., Scott, K. C, Seay, D. A, Segovia, J., Semenov-Tian-Shansky, K., Seryi, A., Sharda, A. S, Shepherd, M. R., Shirokov, E. V., Shrestha, S., Shrestha, U., Shvedunov, V. I., Signori, A., Slifer, K. J., Smith, W. A., Somov, A., Souder, P., Sparveris, N., Spizzo, F., Spreafico, M., Stepanyan, S., Stevens, J. R., Strakovsky, I. I., Strauch, S., Strikman, M., Su, S., Sumner, B. C. L., Sun, E., Suresh, M., Sutera, C., Swanson, E. S., Szczepaniak, A. P, Sznajder, P., Szumila-Vance, H., Szymanowski, L., Tadepalli, A. -S., Tadevosyan, V., Tamang, B., Tarasov, V. V., Thiel, A., Tong, X. -B., Tyson, R., Ungaro, M., Urciuoli, G. M., Usman, A., Valcarce, A., Vallarino, S., Vaquera-Araujo, C. A., Venturelli, L., Vera, F., Vladimirov, A., Vossen, A., Wagner, J., Wei, X., Weinstein, L. B., Weiss, C., Williams, R., Winney, D., Wojtsekhowski, B., Wood, M. H., Xiao, T., Xu, S. -S., Ye, Z., Yero, C., Yuan, C. -P., Yurov, M., Zachariou, N., Zhang, Z., Zhao, Z. W., Zhao, Y., Zheng, X., Zhou, X., Ziegler, V., Zihlmann, B., de Paula, W, and de Téramond, G. F.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology, Nuclear Theory
Abstract: This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena., Comment: Updates to the list of authors; Preprint number changed from theory to experiment; Updates to sections 4 and 6, including additional figures
Published: 2023

7. First measurement of hard exclusive $\pi^- \Delta^{++}$ electroproduction beam-spin asymmetries off the proton

Author: Diehl, S., Trotta, N., Joo, K., Achenbach, P., Akbar, Z., Armstrong, W. R., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bossu, F., Brinkmann, K. -T., Briscoe, W. J., Bulumulla, D., Burkert, V., Capobianco, R., Carman, D. S., Carvajal, J. C., Celentano, A., Charles, G., Chatagnon, P., Chesnokov, V., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Djalali, C., Dupre, R., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gavalian, G., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Griffioen, K., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Illari, I., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Klimenko, V., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., MacGregor, I . J . D., Marchand, D., Mascagna, V., Matousek, G., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Moran, P., Camacho, C. Munoz, Naidoo, P., Neupane, K., Niccolai, S., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Radic, A., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatie, F., Salgado, C., Schadmand, S., Schmidt, A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I., Strauch, S., Turisini, M., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Wishart, R., Wood, M. H., Yurov, M., Zachariou, N., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment
Abstract: The polarized cross section ratio $\sigma_{LT'}/\sigma_{0}$ from hard exclusive $\pi^{-} \Delta^{++}$ electroproduction off an unpolarized hydrogen target has been extracted based on beam-spin asymmetry measurements using a 10.2 GeV / 10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. The study, which provides the first observation of this channel in the deep-inelastic regime, focuses on very forward-pion kinematics in the valence regime, and photon virtualities ranging from 1.5 GeV$^{2}$ up to 7 GeV$^{2}$. The reaction provides a novel access to the $d$-quark content of the nucleon and to $p \rightarrow \Delta^{++}$ transition generalized parton distributions. A comparison to existing results for hard exclusive $\pi^{+} n$ and $\pi^{0} p$ electroproduction is provided, which shows a clear impact of the excitation mechanism, encoded in transition generalized parton distributions, on the asymmetry.
Published: 2023
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8. The Present and Future of QCD

Author: Achenbach, P., Adhikari, D., Afanasev, A., Afzal, F., Aidala, C. A., Al-bataineh, A., Almaalol, D. K., Amaryan, M., Androić, D., Armstrong, W. R., Arratia, M., Arrington, J., Asaturyan, A., Aschenauer, E. C., Atac, H., Avakian, H., Averett, T., Gayoso, C. Ayerbe, Bai, X., Barish, K. N., Barnea, N., Basar, G., Battaglieri, M., Baty, A. A., Bautista, I., Bazilevsky, A., Beattie, C., Behera, S. C., Bellini, V., Bellwied, R., Benesch, J. F., Benmokhtar, F., Bernardes, C. A., Bernauer, J. C., Bhatt, H., Bhatta, S., Boer, M., Boettcher, T. J., Bogacz, S. A., Bossi, H. J., Brandenburg, J. D., Brash, E. J., Briceño, R. A., Briscoe, W. J., Brodsky, S. J., Brown, D. A., Burkert, V. D., Caines, H., Cali, I. A., Camsonne, A., Carman, D. S., Caylor, J., Cerci, S., Llatas, M. Chamizo, Chatterjee, S., Chen, J. P., Chen, Y., Chen, Y. -C., Chien, Y. -T., Chou, P. -C., Chu, X., Chudakov, E., Cline, E., Cloët, I. C., Cole, P. L., Connors, M. E., Constantinou, M., Cosyn, W., Dusa, S. Covrig, Cruz-Torres, R., D'Alesio, U., da Silva, C., Davoudi, Z., Dean, C. T., Dean, D. J., Demarteau, M., Deshpande, A., Detmold, W., Deur, A., Devkota, B. R., Dhital, S., Diefenthaler, M., Dobbs, S., Döring, M., Dong, X., Dotel, R., Dow, K. A., Downie, E. J., Drachenberg, J. L., Dumitru, A., Dunlop, J. C., Dupre, R., Durham, J. M., Dutta, D., Edwards, R. G., Ehlers, R. J., Fassi, L. El, Elaasar, M., Elouadrhiri, L., Engelhardt, M., Ent, R., Esumi, S., Evdokimov, O., Eyser, O., Fanelli, C., Fatemi, R., Fernando, I. P., Flor, F. A., Fomin, N., Frawley, A. D., Frederico, T., Fries, R. J., Gal, C., Gamage, B. R., Gamberg, L., Gao, H., Gaskell, D., Geurts, F., Ghandilyan, Y., Ghimire, N., Gilman, R., Gleason, C., Gnanvo, K., Gothe, R. W., Greene, S. V., Grießhammer, H. W., Grossberndt, S. K., Grube, B., Hackett, D. C., Hague, T. J., Hakobyan, H., Hansen, J. -O., Hatta, Y., Hattawy, M., Havener, L. B., Hen, O., Henry, W., Higinbotham, D. W., Hobbs, T. J., Hodges, A. M., Holmstrom, T., Hong, B., Horn, T., Howell, C. R., Huang, H. Z., Huang, M., Huang, S., Huber, G. M., Hyde, C. E., Isupov, E. L., Jacobs, P. M., Jalilian-Marian, J., Jentsch, A., Jheng, H., Ji, C. -R., Ji, X., Jia, J., Jones, D. C., Jones, M. K., Kalantarians, N., Kalicy, G., Kang, Z. B., Karthein, J. M., Keller, D., Keppel, C., Khachatryan, V., Kharzeev, D. E., Kim, H., Kim, M., Kim, Y., King, P. M., Kinney, E., Klein, S. R., Ko, H. S., Koch, V., Kohl, M., Kovchegov, Y. V., Krintiras, G. K., Kubarovsky, V., Kuhn, S. E., Kumar, K. S., Kutz, T., Lajoie, J. G., Lauret, J., Lavrukhin, I., Lawrence, D., Lee, J. H., Lee, K., Lee, S., Lee, Y. -J., Li, S., Li, W., Li, Xiaqing, Li, Xuan, Liao, J., Lin, H. -W., Lisa, M. A., Liu, K. -F., Liu, M. X., Liu, T., Liuti, S., Liyanage, N., Llope, W. J., Loizides, C., Longo, R., Lorenzon, W., Lunkenheimer, S., Luo, X., Ma, R., McKinnon, B., Meekins, D. G., Mehtar-Tani, Y., Melnitchouk, W., Metz, A., Meyer, C. A., Meziani, Z. -E., Michaels, R., Michel, J. K. L., Milner, R. G., Mkrtchyan, H., Mohanmurthy, P., Mohanty, B., Mokeev, V. I., Moon, D. H., Mooney, I. A., Morningstar, C., Morrison, D. P., Müller, B., Mukherjee, S., Mulligan, J., Camacho, C. Munoz, Quijada, J. A. Murillo, Murray, M. J., Nadeeshani, S. A., Nadel-Turonski, P., Nam, J. D., Nattrass, C. E., Nijs, G., Noronha, J., Noronha-Hostler, J., Novitzky, N., Nycz, M., Olness, F. I., Osborn, J. D., Pak, R., Pandey, B., Paolone, M., Papandreou, Z., Paquet, J. -F., Park, S., Paschke, K. D., Pasquini, B., Pasyuk, E., Patel, T., Patton, A., Paudel, C., Peng, C., Peng, J. C., Da Costa, H. Pereira, Perepelitsa, D. V., Peters, M. J., Petreczky, P., Pisarski, R. D., Pitonyak, D., Ploskon, M. A., Posik, M., Poudel, J., Pradhan, R., Prokudin, A., Pruneau, C. A., Puckett, A. J. R., Pujahari, P., Putschke, J., Pybus, J. R., Qiu, J. -W., Rajagopal, K., Ratti, C., Read, K. F., Reed, R., Richards, D. G., Riedl, C., Ringer, F., Rinn, T., West, J. Rittenhouse, Roche, J., Rodas, A., Roland, G., Romero-López, F., Rossi, P., Rostomyan, T., Ruan, L., Ruimi, O. M., Saha, N. R., Sahoo, N. R., Sakaguchi, T., Salazar, F., Salgado, C. W., Salmè, G., Salur, S., Santiesteban, S. N., Sargsian, M. M., Sarsour, M., Sato, N., Satogata, T., Sawada, S., Schäfer, T., Scheihing-Hitschfeld, B., Schenke, B., Schindler, S. T., Schmidt, A., Seidl, R., Shabestari, M. H., Shanahan, P. E., Shen, C., Sheng, T. -A., Shepherd, M. R., Sickles, A. M., Sievert, M. D., Smith, K. L., Song, Y., Sorensen, A., Souder, P. A., Sparveris, N., Srednyak, S., Leiton, A. G. Stahl, Stasto, A. M., Steinberg, P., Stepanyan, S., Stephanov, M., Stevens, J. R., Stewart, D. J., Stewart, I. W., Stojanovic, M., Strakovsky, I., Strauch, S., Strickland, M., Cerci, D. Sunar, Suresh, M., Surrow, B., Syritsyn, S., Szczepaniak, A. P., Tadepalli, A. S., Tang, A. H., Takaki, J. D. Tapia, Tarnowsky, T. J., Tawfik, A. N., Taylor, M. I., Tennant, C., Thiel, A., Thomas, D., Tian, Y., Timmins, A. R., Tribedy, P., Tu, Z., Tuo, S., Ullrich, T., Umaka, E., Upton, D. W., Vary, J. P., Velkovska, J., Venugopalan, R., Vijayakumar, A., Vitev, I., Vogelsang, W., Vogt, R., Vossen, A., Voutier, E., Vovchenko, V., Walker-Loud, A., Wang, F., Wang, J., Wang, X., Wang, X. -N., Weinstein, L. B., Wenaus, T. J., Weyhmiller, S., Wissink, S. W., Wojtsekhowski, B., Wong, C. P., Wood, M. H., Wunderlich, Y., Wyslouch, B., Xiao, B. W., Xie, W., Xiong, W., Xu, N., Xu, Q. H., Xu, Z., Yaari, D., Yao, X., Ye, Z., Ye, Z. H., Yero, C., Yuan, F., Zajc, W. A., Zhang, C., Zhang, J., Zhao, F., Zhao, Y., Zhao, Z. W., Zheng, X., Zhou, J., and Zurek, M.
Subjects: High Energy Physics - Phenomenology, High Energy Physics - Experiment, Nuclear Experiment, Nuclear Theory
Abstract: This White Paper presents the community inputs and scientific conclusions from the Hot and Cold QCD Town Meeting that took place September 23-25, 2022 at MIT, as part of the Nuclear Science Advisory Committee (NSAC) 2023 Long Range Planning process. A total of 424 physicists registered for the meeting. The meeting highlighted progress in Quantum Chromodynamics (QCD) nuclear physics since the 2015 LRP (LRP15) and identified key questions and plausible paths to obtaining answers to those questions, defining priorities for our research over the coming decade. In defining the priority of outstanding physics opportunities for the future, both prospects for the short (~ 5 years) and longer term (5-10 years and beyond) are identified together with the facilities, personnel and other resources needed to maximize the discovery potential and maintain United States leadership in QCD physics worldwide. This White Paper is organized as follows: In the Executive Summary, we detail the Recommendations and Initiatives that were presented and discussed at the Town Meeting, and their supporting rationales. Section 2 highlights major progress and accomplishments of the past seven years. It is followed, in Section 3, by an overview of the physics opportunities for the immediate future, and in relation with the next QCD frontier: the EIC. Section 4 provides an overview of the physics motivations and goals associated with the EIC. Section 5 is devoted to the workforce development and support of diversity, equity and inclusion. This is followed by a dedicated section on computing in Section 6. Section 7 describes the national need for nuclear data science and the relevance to QCD research., Comment: QCD Town Meeting White Paper, as submitted to 2023 NSAC LRP committee on Feb. 28, 2023
Published: 2023
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9. Searching for Prompt and Long-Lived Dark Photons in Electro-Produced $e^+e^-$ Pairs with the Heavy Photon Search Experiment at JLab

Author: Adrian, P. H., Baltzell, N. A., Battaglieri, M., Bondi, M., Boyarinov, S., Bravo, C., Bueltmann, S., Butti, P., Burkert, V. D., Calvo, D., Cao, T., Carpinelli, M., Celentano, A., Charles, G., Colaneri, L., Cooper, W., Cuevas, C., D'Angelo, A., Dashyan, N., De Napoli, M., De Vita, R., Deur, A., Diamond, M., Dupre, R., Egiyan, H., Elouadrhiri, L., Essig, R., Fadeyev, V., Field, C., Filippi, A., Freyberger, A., Garcon, M., Gevorgyan, N., Girod, F. X., Graf, N., Graham, M., Griffioen, K. A., Grillo, A., Guidal, M., Herbst, R., Holtrop, M., Jaros, J., Johnson, R. P., Kalicy, G., Khandaker, M., Kubarovsky, V., Leonora, E., Livingston, K., Marsicano, L., Maruyama, T., McCarty, S., McCormick, J., McKinnon, B., Moffeit, K., Moreno, O., Camacho, C. Munoz, Nelson, T., Niccolai, S., Odian, A., Oriunno, M., Osipenko, M., Paremuzyan, R., Paul, S., Randazzo, N., Raydo, B., Reese, B., Rizzo, A., Schuster, P., Sharabian, Y. G., Simi, G., Simonyan, A., Sipala, V., Spellman, A., Sokhan, D., Solt, M., Stepanyan, S., Szumila-Vance, H., Toro, N., Uemura, S., Ungaro, M., Voskanyan, H., Weinstein, L. B., Wojtsekhowski, B., and Yale, B.
Subjects: High Energy Physics - Experiment
Abstract: The Heavy Photon Search experiment (HPS) at the Thomas Jefferson National Accelerator Facility searches for electro-produced dark photons. We report results from the 2016 Engineering Run consisting of 10608/nb of data for both the prompt and displaced vertex searches. A search for a prompt resonance in the $e^+e^-$ invariant mass distribution between 39 and 179 MeV showed no evidence of dark photons above the large QED background, limiting the coupling of {\epsilon}^2 {\geq} 10^-5, in agreement with previous searches. The search for displaced vertices showed no evidence of excess signal over background in the masses between 60 and 150 MeV, but had insufficient luminosity to limit canonical heavy photon production. This is the first displaced vertex search result published by HPS. HPS has taken high-luminosity data runs in 2019 and 2021 that will explore new dark photon phase space., Comment: 28 pages, 46 figures
Published: 2022
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10. First CLAS12 measurement of DVCS beam-spin asymmetries in the extended valence region

Author: CLAS Collaboration, Christiaens, G., Defurne, M., Sokhan, D., Achenbach, P., Akbar, Z., Amaryan, M. J., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Booth, W. A., Bossù, F., Boiarinov, S., Brinkmann, K. -Th., Briscoe, W. J., Bueltmann, S., Bulumulla, D., Burkert, V. D., Cao, T., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gates, K., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hobart, A., Holmberg, D. E., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Kabir, M. L., Keller, D., Khachatryan, M., Khanal, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I . J . D., Marchand, D., Mascagna, V., Matousek, G., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Molina, E., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Radic, A., Ramasubramanian, N., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Scott, M. B. C., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sparveris, N., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Turisini, M., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., Ziegler, V., and Zurek, M.
Subjects: High Energy Physics - Experiment
Abstract: Deeply virtual Compton scattering (DVCS) allows one to probe Generalized Parton Distributions (GPDs) describing the 3D structure of the nucleon. We report the first measurement of the DVCS beam-spin asymmetry using the CLAS12 spectrometer with a 10.2 and 10.6 GeV electron beam scattering from unpolarised protons. The results greatly extend the $Q^2$ and Bjorken-$x$ phase space beyond the existing data in the valence region and provide over 2000 new data points measured with unprecedented statistical uncertainty, setting new, tight constraints for future phenomenological studies., Comment: Revised Figure 4 and discussion around the number of effective ANNs after Bayesian reweighting
Published: 2022

11. A multidimensional study of the structure function ratio $\sigma_{LT'}/\sigma_{0}$ from hard exclusive $\pi^+$ electro-production off protons in the GPD regime

Author: Diehl, S., Kim, A., Joo, K., Achenbach, P., Akbar, Z., Amaryan, M. J., Atac, H., Avagyan, H., Gayoso, C. Ayerbe, Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Booth, W. A., Bossu, F., Boiarinov, S., Brinkmann, K. -Th., Briscoe, W. J., Bueltmann, S., Bulumulla, D., Burkert, V. D., Carman, D. S., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Grifoen, K. A., Guidal, M., Hafdi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Khachatryan, M., Khanal, A., Kim, W., Kripko, A., Kubarovsky, V., Lagerquist, V., Laget, J. -M., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I . J. D., Marchand, D., Mascagna, V., McKinnon, B., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Molina, Esteban, Montgomery, R. A., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Reed, Trevor, Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatie, F., Salgado, C., Schadmand, S., Schmidt, A., Sharabian, Y., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Spreafco, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Turisini, M., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment
Abstract: A multidimensional extraction of the structure function ratio $\sigma_{LT'}/\sigma_{0}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region has been performed. The study was done based on beam-spin asymmetry measurements using a 10.6 GeV incident electron beam on a liquid-hydrogen target and the CLAS12 spectrometer at Jefferson Lab. The measurements focus on the very forward regime ($t/Q^{2}$ $\ll$ 1) with a wide kinematic range of $x_{B}$ in the valence regime (0.17 $<$ $x_{B}$ $<$ 0.55), and virtualities $Q^{2}$ ranging from 1.5 GeV$^{2}$ up to 6 GeV$^{2}$. The results and their comparison to theoretical models based on Generalized Parton Distributions demonstrate the sensitivity to chiral-odd GPDs and the directly related tensor charge of the nucleon. In addition, the data is compared to an extension of a Regge formalism at high photon virtualities. It was found that the Regge model provides a better description at low $Q^{2}$, while the GPD model is more appropriate at high $Q^{2}$., Comment: arXiv admin note: text overlap with arXiv:2007.15677
Published: 2022
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12. First Measurement of $\Lambda$ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

Author: Chetry, T., Fassi, L. El, Brooks, W. K., Dupré, R., Alaoui, A. El, Hafidi, K., Achenbach, P., Adhikari, K. P., Akbar, Z., Armstrong, W. R., Arratia, M., Atac, H., Avakian, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Booth, W. A., Bossù, F., Boiarinov, S., Brinkmann, K. -Th., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Egiyan, H., Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Kabir, M. L., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I. J. D., Marchand, D., Mascagna, V., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rosner, G., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Wei, X., Weinstein, L. B., Williams, R., Wishart, R., Wood, M. H., Zachariou, N., Zhao, Z. W., and Zurek, M.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: We report results of $\Lambda$ hyperon production in semi-inclusive deep-inelastic scattering off deuterium, carbon, iron, and lead targets obtained with the CLAS detector and the Continuous Electron Beam Accelerator Facility 5.014~GeV electron beam. These results represent the first measurements of the $\Lambda$ multiplicity ratio and transverse momentum broadening as a function of the energy fraction~($z$) in the current and target fragmentation regions. The multiplicity ratio exhibits a strong suppression at high~$z$~and~an enhancement at~low~$z$. The measured transverse momentum broadening is an order of magnitude greater than that seen for light mesons. This indicates that the propagating entity interacts very strongly with the nuclear medium, which suggests that propagation of diquark configurations in the nuclear medium takes place at least part of the time, even at high~$z$. The trends of these results are qualitatively described by the Giessen Boltzmann-Uehling-Uhlenbeck transport model, particularly for the multiplicity ratios. These observations will potentially open a new era of studies of the structure of the nucleon as well as of strange baryons., Comment: 14 pages, 6 figures
Published: 2022
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13. First observation of correlations between spin and transverse momenta in back-to-back dihadron production at CLAS12

Author: Avakian, H., Hayward, T. B., Kotzinian, A., Armstrong, W. R., Atac, H., Gayoso, C. Ayerbe, Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Boiarinov, S., Bossù, F., Brinkman, K. T., Briscoe, W. J., Brooks, W. K., Bueltmann, S., Bulumulla, D., Burkert, V. D., Capobianco, R., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T., Gates, K., Gavalian, G., Gilyan, Y., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hakobyan, H., Hattawy, M., Hauenstein, F., Heddle, D., Hobart, A., Holtrop, M., Hyde, C. E., Ilieva, Y., Ire, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Joo, K., Kabir, M. L., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Klimenko, V., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., MacGregor, I . J . D., Marc, D., Mascagna, V., McKinnon, B., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Montgomery, R. A., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Nguyen, D., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Richards, J., Ripani, M., Ritman, J., Rossi, P., Sabatié, F., Salgado, C., Schmidt, A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, X., Wishart, R., Wood, M. H., Zachariou, N., Zhao, Z. W., and Zurek, M.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report the first measurements of deep inelastic scattering spin-dependent azimuthal asymmetries in back-to-back dihadron electroproduction, where two hadrons are produced in opposite hemispheres along the z-axis in the center-of-mass frame, with the first hadron produced in the current-fragmentation region and the second in the target-fragmentation region. The data were taken with longitudinally polarized electron beams of 10.2 and 10.6 GeV incident on an unpolarized liquid-hydrogen target using the CLAS12 spectrometer at Jefferson Lab. Observed non-zero $\sin\Delta\phi$ modulations in $ep \rightarrow e'p\pi^+X$ events, where $\Delta\phi$ is the difference of the azimuthal angles of the proton and pion in the virtual photon and target nucleon center-of-mass frame, indicate that correlations between the spin and transverse momenta of hadrons produced in the target- and current-fragmentation regions may be significant. The measured beam-spin asymmetries provide a first access in dihadron production to a previously unobserved leading-twist spin- and transverse-momentum-dependent fracture function. The fracture functions describe the hadronization of the target remnant after the hard scattering of a virtual photon off a quark in the target particle and provide a new avenue for studying nucleonic structure and hadronization., Comment: 7 pages, 6 figures
Published: 2022
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14. Alignment of the CLAS12 central hybrid tracker with a Kalman Filter

Author: Paul, S. J., Peck, A., Arratia, M., Gotra, Y., Ziegler, V., De Vita, R., Bossu, F., Defurne, M., Atac, H., Gayoso, C. Ayerbe, Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Boiarinov, S., Brinkmann, K. Th., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Capobianco, R., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P. L., Costantini, G., Angelo, A. D, Dashyan, N., Deur, A., Diehl, S., Djalali, C., Dupre, R., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Filippi, A., Gates, K., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Golubenko, A. A., Gosta, G., Gothe, R. W., Griffioen, K., Guidal, M., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Joo, K., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Klimenko, V., Kripko, A., Lanza, L., Leali, M., Lenisa, P., Li, X., MacGregor, I. J. D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Nguyen, D., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Paremuzyan, R., Pilleux, N., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Reed, T., Ripani, M., Ritman, J., Sabatie, F., Schadmand, S., Schmidt, A., Shirokov, E. V., Shrestha, U., Simmerling, P., Spreafico, M., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Wishart, R., Wood, M. H., and Zachariou, N.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract: Several factors can contribute to the difficulty of aligning the sensors of tracking detectors, including a large number of modules, multiple types of detector technologies, and non-linear strip patterns on the sensors. All three of these factors apply to the CLAS12 CVT, which is a hybrid detector consisting of planar silicon sensors with non-parallel strips, and cylindrical micromegas sensors with longitudinal and arc-shaped strips located within a 5~T superconducting solenoid. To align this detector, we used the Kalman Alignment Algorithm, which accounts for correlations between the alignment parameters without requiring the time-consuming inversion of large matrices. This is the first time that this algorithm has been adapted for use with hybrid technologies, non-parallel strips, and curved sensors. We present the results for the first alignment of the CLAS12 CVT using straight tracks from cosmic rays and from a target with the magnetic field turned off. After running this procedure, we achieved alignment at the level of 10~$\mu$m, and the widths of the residual spectra were greatly reduced. These results attest to the flexibility of this algorithm and its applicability to future use in the CLAS12 CVT and other hybrid or curved trackers, such as those proposed for the future Electron-Ion Collider.
Published: 2022
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15. Machine Learned Particle Detector Simulations

Author: Darulis, D., Tyson, R., Ireland, D. G., Glazier, D. I., McKinnon, B., and Pauli, P.
Subjects: Physics - Data Analysis, Statistics and Probability, High Energy Physics - Experiment, Nuclear Experiment
Abstract: The use of machine learning algorithms is an attractive way to produce very fast detector simulations for scattering reactions that can otherwise be computationally expensive. Here we develop a factorised approach where we deal with each particle produced in a reaction individually: first determine if it was detected (acceptance) and second determine its reconstructed variables such as four momentum (reconstruction). For the acceptance we propose using a probability classification density ratio technique to determine the probability the particle was detected as a function of many variables. Neural Network and Boosted Decision Tree classifiers were tested for this purpose and we found using a combination of both, through a reweighting stage, provided the most reliable results. For reconstruction a simple method of synthetic data generation, based on nearest neighbour or decision trees was developed. Using a toy parameterised detector we demonstrate that such a method can reliably and accurately reproduce kinematic distributions from a physics reaction. The relatively simple algorithms allow for small training overheads whilst producing reliable results. Possible applications for such fast simulated data include Toy-MC studies of parameter extraction, preprocessing expensive simulations or generating templates for background distributions shapes.
Published: 2022

16. Observation of azimuth-dependent suppression of hadron pairs in electron scattering off nuclei

Author: Paul, S. J., Moran, S., Arratia, M., Alaoui, A. El, Hakobyan, H., Brooks, W., Amaryan, M. J., Armstrong, W. R., Atac, H., Baashen, L., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Brinkmann, K. Th., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Capobianco, R., Carman, D. S., Celentano, A., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Fassi, L. El, Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Golubenko, A. A., Gosta, G., Gothe, R. W., Griffioen, K. A., Guidal, M., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, W., Kripko, A., Kubarovsky, V., Lagerquist, V., Lanza, L., Leali, M., Lee, S., Lenisa, P., Li, X., Livingston, K., MacGregor, I. J. D., Marchand, D., Mascagna, V., McKinnon, B., Meziani, Z. E., Migliorati, S., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V. I., Moran, P., Camacho, C. Munoz, Neupane, K., Nguyen, D., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pilleux, N., Pocanic, D., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Ripani, M., Rosner, G., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Wei, X., Wishart, R., Wood, M. H., Zachariou, N., Zhao, Z. W., Ziegler, V., and Zurek, M.
Subjects: Nuclear Experiment
Abstract: We present the first measurement of di-hadron angular correlations in electron-nucleus scattering. The data were taken with the CLAS detector and a 5.0 GeV electron beam incident on deuterium, carbon, iron, and lead targets. Relative to deuterium, the nuclear yields of charged-pion pairs show a strong suppression for azimuthally opposite pairs, no suppression for azimuthally nearby pairs, and an enhancement of pairs with large invariant mass. These effects grow with increased nuclear size. The data are qualitatively described by the GiBUU model, which suggests that hadrons form near the nuclear surface and undergo multiple-scattering in nuclei. These results show that angular correlation studies can open a new way to elucidate how hadrons form and interact inside nuclei, Comment: 6 pages, 4 figures
Published: 2022
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17. Exclusive $\pi^{-}$ Electroproduction off the Neutron in Deuterium in the Resonance Region

Author: Tian, Y., Gothe, R. W., Mokeev, V. I., Hollis, G., Amaryan, M. J., Armstrong, W. R., Atac, H., Avakian, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A., Bossù, F., Boiarinov, S., Bondì, M., Brinkmann, K. T., Briscoe, W. J., Bueltmann, S., Bulumulla, D., Burkert, V. D., Capobianco, R., Carman, D. S., Carvajal, J. C., Celentano, A., Chesnokov, V., Chetry, T., Ciullo, G., Clash, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Golubenko, A. A., Gosta, G., Griffioen, K., Guidal, M., Hakobyan, H., Hattawy, M., Hayward, T. B., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lagerquist, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. . J . D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., Migliorati, S., Mineeva, T., Mirazita, M., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Newton, J., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Počanić, D., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Reed, T., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schadmand, S., Schmidt, A., Schumacher, R. A., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., and Zhang, J.
Subjects: Nuclear Experiment
Abstract: New results for the exclusive and quasi-free cross sections off neutrons bound in deuterium ${\gamma}_vn(p) \rightarrow p{\pi}^{-} (p)$ are presented over a wide final state hadron angle range with a kinematic coverage of the invariant mass ($W$) up to 1.825 GeV and the virtual photon four-momentum transfer squared ($Q^{2}$) from 0.4 to 1.0 GeV$^2$. The exclusive structure functions were extracted and their Legendre moments were obtained. Final-state-interaction contributions have been kinematically separated from the extracted quasi-free cross sections off bound neutrons solely based on the analysis of the experimental data. These new results will serve as long-awaited input for phenomenological analyses to extract the $Q^{2}$ evolution of previously unavailable $n \to N^{*}$ electroexcitation amplitudes and to improve state-of-the-art models of neutrino scattering off nuclei by augmenting the already available results from free protons., Comment: The author list has been updated
Published: 2022
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18. Beam-Recoil Transferred Polarization in $K^+Y$ Electroproduction in the Nucleon Resonance Region with CLAS12

Author: Carman, D. S., D'Angelo, A., Lanza, L., Mokeev, V. I., Adhikari, K. P., Amaryan, M. J., Armstrong, W. R., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Bianconi, A., Biselli, A. S., Bondi, M., Boiarinov, S., Bossu, F., Briscoe, W. J., Bueltmann, S., Bulumulla, D., Burkert, V. D., Capobianco, R., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Gotra, Y., Griffioen, K. A., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Keller, D., Khanal, A., Kim, A., Kim, W., Klimenko, V., Kripko, A., Kubarovsky, V., Leali, M., Lee, S., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Marsicano, L., Mascagna, V., Mayer, M., McKinnon, B., Migliorati, S., Mineeva, T., Mirazita, M., Montgomery, R. A., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Newton, J., Niccolai, S., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Pilleux, N., Pogorelko, O., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Sabatie, F., Salgado, C., Schmidt, A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyler, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wishart, R., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Ziegler, V.
Subjects: Nuclear Experiment
Abstract: Beam-recoil transferred polarizations for the exclusive electroproduction of $K^+\Lambda$ and $K^+\Sigma^0$ final states from an unpolarized proton target have been measured using the CLAS12 spectrometer at Jefferson Laboratory. The measurements at beam energies of 6.535~GeV and 7.546~GeV span the range of four-momentum transfer $Q^2$ from 0.3 to 4.5~GeV$^2$ and invariant energy $W$ from 1.6 to 2.4~GeV, while covering the full center-of-mass angular range of the $K^+$. These new data extend the existing hyperon polarization data from CLAS in a similar kinematic range but from a significantly larger dataset. They represent an important addition to the world data, allowing for better exploration of the reaction mechanism in strangeness production processes, for further understanding of the spectrum and structure of excited nucleon states, and for improved insight into the strong interaction in the regime of non-perturbative dynamics., Comment: 25 pages, 22 figures, 4 tables
Published: 2022
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19. The present and future of QCD

Author: Achenbach, P., Adhikari, D., Afanasev, A., Afzal, F., Aidala, C.A., Al-bataineh, A., Almaalol, D.K., Amaryan, M., Androić, D., Armstrong, W.R., Arratia, M., Arrington, J., Asaturyan, A., Aschenauer, E.C., Atac, H., Avakian, H., Averett, T., Ayerbe Gayoso, C., Bai, X., Barish, K.N., Barnea, N., Basar, G., Battaglieri, M., Baty, A.A., Bautista, I., Bazilevsky, A., Beattie, C., Behera, S.C., Bellini, V., Bellwied, R., Benesch, J.F., Benmokhtar, F., Bernardes, C.A., Bernauer, J.C., Bhatt, H., Bhatta, S., Boer, M., Boettcher, T.J., Bogacz, S.A., Bossi, H.J., Brandenburg, J.D., Brash, E.J., Briceño, R.A., Briscoe, W.J., Brodsky, S.J., Brown, D.A., Burkert, V.D., Caines, H., Cali, I.A., Camsonne, A., Carman, D.S., Caylor, J., Cerci, D.S., Cerci, S., Chamizo Llatas, M., Chatterjee, S., Chen, J.P., Chen, Y., Chen, Y.-C., Chien, Y.-T., Chou, P.-C., Chu, X., Chudakov, E., Cline, E., Cloët, I.C., Cole, P.L., Connors, M.E., Constantinou, M., Cosyn, W., Covrig Dusa, S., Cruz-Torres, R., D'Alesio, U., da Silva, C., Davoudi, Z., Dean, C.T., Dean, D.J., Demarteau, M., Deshpande, A., Detmold, W., Deur, A., Devkota, B.R., Dhital, S., Diefenthaler, M., Dobbs, S., Döring, M., Dong, X., Dotel, R., Dow, K.A., Downie, E.J., Drachenberg, J.L., Dumitru, A., Dunlop, J.C., Dupre, R., Durham, J.M., Dutta, D., Edwards, R.G., Ehlers, R.J., El Fassi, L., Elaasar, M., Elouadrhiri, L., Engelhardt, M., Ent, R., Esumi, S., Evdokimov, O., Eyser, O., Fanelli, C., Fatemi, R., Fernando, I.P., Flor, F.A., Fomin, N., Frawley, A.D., Frederico, T., Fries, R.J., Gal, C., Gamage, B.R., Gamberg, L., Gao, H., Gaskell, D., Geurts, F., Ghandilyan, Y., Ghimire, N., Gilman, R., Gleason, C., Gnanvo, K., Gothe, R.W., Greene, S.V., Grießhammer, H.W., Grossberndt, S.K., Grube, B., Hackett, D.C., Hague, T.J., Hakobyan, H., Hansen, J.-O., Hatta, Y., Hattawy, M., Havener, L.B., Hen, O., Henry, W., Higinbotham, D.W., Hobbs, T.J., Hodges, A.M., Holmstrom, T., Hong, B., Horn, T., Howell, C.R., Huang, H.Z., Huang, M., Huang, S., Huber, G.M., Hyde, C.E., Isupov, E.L., Jacobs, P.M., Jalilian-Marian, J., Jentsch, A., Jheng, H., Ji, C.-R., Ji, X., Jia, J., Jones, D.C., Jones, M.K., Joosten, S., Kalantarians, N., Kalicy, G., Kang, Z.B., Karthein, J.M., Keller, D., Keppel, C., Khachatryan, V., Kharzeev, D.E., Kim, H., Kim, M., Kim, Y., King, P.M., Kinney, E., Klein, S.R., Ko, H.S., Koch, V., Kohl, M., Kovchegov, Y.V., Krintiras, G.K., Kubarovsky, V., Kuhn, S.E., Kumar, K.S., Kutz, T., Lajoie, J.G., Lauret, J., Lavrukhin, I., Lawrence, D., Lee, J.H., Lee, K., Lee, S., Lee, Y.-J., Li, S., Li, W., Li, Xiaqing, Li, Xuan, Liao, J., Lin, H.-W., Lisa, M.A., Liu, K.-F., Liu, M.X., Liu, T., Liuti, S., Liyanage, N., Llope, W.J., Loizides, C., Longo, R., Lorenzon, W., Lunkenheimer, S., Luo, X., Ma, R., McKinnon, B., Meekins, D.G., Mehtar-Tani, Y., Melnitchouk, W., Metz, A., Meyer, C.A., Meziani, Z.-E., Michaels, R., Michel, J.K.L., Milner, R.G., Mkrtchyan, H., Mohanmurthy, P., Mohanty, B., Mokeev, V.I., Moon, D.H., Mooney, I.A., Morningstar, C., Morrison, D.P., Müller, B., Mukherjee, S., Mulligan, J., Munoz Camacho, C., Murillo Quijada, J.A., Murray, M.J., Nadeeshani, S.A., Nadel-Turonski, P., Nam, J.D., Nattrass, C.E., Nijs, G., Noronha, J., Noronha-Hostler, J., Novitzky, N., Nycz, M., Olness, F.I., Osborn, J.D., Pak, R., Pandey, B., Paolone, M., Papandreou, Z., Paquet, J.-F., Park, S., Paschke, K.D., Pasquini, B., Pasyuk, E., Patel, T., Patton, A., Paudel, C., Peng, C., Peng, J.C., Pereira Da Costa, H., Perepelitsa, D.V., Peters, M.J., Petreczky, P., Pisarski, R.D., Pitonyak, D., Ploskon, M.A., Posik, M., Poudel, J., Pradhan, R., Prokudin, A., Pruneau, C.A., Puckett, A.J.R., Pujahari, P., Putschke, J., Pybus, J.R., Qiu, J.-W., Rajagopal, K., Ratti, C., Read, K.F., Reed, R., Richards, D.G., Riedl, C., Ringer, F., Rinn, T., Rittenhouse West, J., Roche, J., Rodas, A., Roland, G., Romero-López, F., Rossi, P., Rostomyan, T., Ruan, L., Ruimi, O.M., Saha, N.R., Sahoo, N.R., Sakaguchi, T., Salazar, F., Salgado, C.W., Salmè, G., Salur, S., Santiesteban, S.N., Sargsian, M.M., Sarsour, M., Sato, N., Satogata, T., Sawada, S., Schäfer, T., Scheihing-Hitschfeld, B., Schenke, B., Schindler, S.T., Schmidt, A., Seidl, R., Shabestari, M.H., Shanahan, P.E., Shen, C., Sheng, T.-A., Shepherd, M.R., Sickles, A.M., Sievert, M.D., Smith, K.L., Song, Y., Sorensen, A., Souder, P.A., Sparveris, N., Srednyak, S., Stahl Leiton, A.G., Stasto, A.M., Steinberg, P., Stepanyan, S., Stephanov, M., Stevens, J.R., Stewart, D.J., Stewart, I.W., Stojanovic, M., Strakovsky, I., Strauch, S., Strickland, M., Sunar Cerci, D., Suresh, M., Surrow, B., Syritsyn, S., Szczepaniak, A.P., Tadepalli, A.S., Tang, A.H., Tapia Takaki, J.D., Tarnowsky, T.J., Tawfik, A.N., Taylor, M.I., Tennant, C., Thiel, A., Thomas, D., Tian, Y., Timmins, A.R., Tribedy, P., Tu, Z., Tuo, S., Ullrich, T., Umaka, E., Upton, D.W., Vary, J.P., Velkovska, J., Venugopalan, R., Vijayakumar, A., Vitev, I., Vogelsang, W., Vogt, R., Vossen, A., Voutier, E., Vovchenko, V., Walker-Loud, A., Wang, F., Wang, J., Wang, X., Wang, X.-N., Weinstein, L.B., Wenaus, T.J., Weyhmiller, S., Wissink, S.W., Wojtsekhowski, B., Wong, C.P., Wood, M.H., Wunderlich, Y., Wyslouch, B., Xiao, B.W., Xie, W., Xiong, W., Xu, N., Xu, Q.H., Xu, Z., Yaari, D., Yao, X., Ye, Z., Ye, Z.H., Yero, C., Yuan, F., Zajc, W.A., Zhang, C., Zhang, J., Zhao, F., Zhao, Y., Zhao, Z.W., Zheng, X., Zhou, J., and Zurek, M.
Published: 2024
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20. Polarized Structure Function $\sigma_{LT'}$ from $\pi^0 p$ Electroproduction Data in the Resonance Region at $0.4$ GeV$^2 < Q^2 < 1.0$ GeV$^2$

Author: Isupov, E. L., Burkert, V. D., Golubenko, A. A., Joo, K., Markov, N. S., Mokeev, V. I., Smith, L. C., Armstrong, W. R., Atac, H., Avakian, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossù, F., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Capobianco, R. A., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chesnokov, V., Ciullo, G., Cole, P. L., Clary, B. A., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Gavalian, G., Gilfoyle, G. P., Glazier, D. I., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Illari, I., Ireland, D. G., Jenkins, D., Jo, H. S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Klimenko, V., Kripko, A., Kubarovsky, V., Lagerquist, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., O'Connell, T., Osipenko, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Phelps, W., Pilleux, N., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Ripani, M., Ritman, J., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Ziegler, V.
Subjects: Nuclear Experiment
Abstract: The first results on the $\sigma_{LT'}$ structure function in exclusive $\pi^0p$ electroproduction at invariant masses of the final state of 1.5 GeV $<$ $W$ $<$ 1.8 GeV and in the range of photon virtualities 0.4 GeV$^2 < Q^2 < 1.0$ GeV$^2$ were obtained from data on beam spin asymmetries and differential cross sections measured with the CLAS detector at Jefferson Lab. The Legendre moments determined from the $\sigma_{LT'}$ structure function have demonstrated sensitivity to the contributions from the nucleon resonances in the second and third resonance regions. These new data on the beam spin asymmetries in $\pi^0p$ electroproduction extend the opportunities for the extraction of the nucleon resonance electroexcitation amplitudes in the mass range above 1.6 GeV., Comment: 7 pages, 3 figures
Published: 2021
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21. Measurement of charged-pion production in deep-inelastic scattering off nuclei with the CLAS detector

Author: Moran, S., Dupre, R., Hakobyan, H., Arratia, M., Brooks, W. K., Borquez, A., Alaoui, A. El, Fassi, L. El, Hafidi, K., Mendez, R., Mineeva, T., Paul, S. J., Amaryan, M. J., Angelini, Giovanni, Armstrong, Whitney R., Atac, H., Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biondo, L., Biselli, A. S., Bossu, F., Boiarinov, S., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Carman, D. S., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Egiyan, H., Elouadrhiri, L., Eugenio, P., Fersch, R., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Golubenko, A. A., Gothe, R. W., Griffioen, K. A., Guidal, M., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Keller, D., Khanal, A., Khandaker, M., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J . D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Ostrovidov, A. I., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, Trevor, Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, Kevin, Wei, X., Weinstein, L. B., Wishart, R., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Background: Energetic quarks in nuclear DIS propagate through the nuclear medium. Processes that are believed to occur inside nuclei include quark energy loss through medium-stimulated gluon bremsstrahlung and intra-nuclear interactions of forming hadrons. More data are required to gain a more complete understanding of these effects. Purpose: To test the theoretical models of parton transport and hadron formation, we compared their predictions for the nuclear and kinematic dependence of pion production in nuclei. Methods: We have measured charged-pion production in semi-inclusive DIS off D, C, Fe, and Pb using the CLAS detector and the CEBAF 5.014 GeV electron beam. We report results on the nuclear-to-deuterium multiplicity ratio for $\pi^{+}$ and $\pi^{-}$ as a function of energy transfer, four-momentum transfer, and pion energy fraction or transverse momentum - the first three-dimensional study of its kind. Results: The $\pi^{+}$ multiplicity ratio is found to depend strongly on the pion fractional energy $z$, and reaches minimum values of $0.67\pm0.03$, $0.43\pm0.02$, and $0.27\pm0.01$ for the C, Fe, and Pb targets, respectively. The $z$ dependences of the multiplicity ratios for $\pi^{+}$ and $\pi^{-}$ are equal within uncertainties for C and Fe targets but show differences at the level of 10$\%$ for the Pb-target data. The results are qualitatively described by the GiBUU transport model, as well as with a model based on hadron absorption, but are in tension with calculations based on nuclear fragmentation functions. Conclusions: These precise results will strongly constrain the kinematic and flavor dependence of nuclear effects in hadron production, probing an unexplored kinematic region. They will help to reveal how the nucleus reacts to a fast quark, thereby shedding light on its color structure, transport properties, and on the mechanisms of the hadronization process., Comment: 22 pages, 5 figures, 12 tables
Published: 2021
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22. First-time measurement of Timelike Compton Scattering

Author: Chatagnon, P., Niccolai, S., Stepanyan, S., Amaryan, M. J., Angelini, G., Armstrong, W. R., Atac, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Caudron, M., Celentano, A., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., Defurne, M., De Vita, R., Deur, A., Diehl, S., Djalali, C., Dupré, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Fersch, R., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Hyde, C. E., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Kabir, M. L., Keller, D., Khachatryan, G., Khanal, A., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., MacGregor, I . J . D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Migliorati, S., Mirazita, M., Mokeev, V., Montgomery, R. A., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., O'Connell, T. R., Osipenko, M., Ouillon, M., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Raue, B. A., Reed, T., Ripani, M., Rizzo, A., Rossi, P., Rowley, J., Sabatié, F., Schmidt, A., Segarra, E. P., Sharabian, Y. G., Shirokov, E. V., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Tyler, N., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wishart, R., Yale, B., Zachariou, N., Zhang, J., Zhao, Z. W., and Collaboration, the CLAS
Subjects: High Energy Physics - Experiment
Abstract: We present the first measurement of the Timelike Compton Scattering process, $\gamma p\to p^\prime \gamma^* (\gamma^*\to e^+e^-) $, obtained with the CLAS12 detector at Jefferson Lab. The photon beam polarization and the decay lepton angular asymmetries are reported in the range of timelike photon virtualities $2.25
Published: 2021
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23. Improved $\Lambda p$ Elastic Scattering Cross Sections Between 0.9 and 2.0 GeV/c and Connections to the Neutron Star Equation of State

Author: CLAS Collaboration, Rowley, J., Compton, N., Djalali, C., Hicks, K., Price, J., Zachariou, N., Adhikari, K. P., Armstrong, W. R., Atac, H., Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Gavalian, G., Girod, F. X., Glazier, D. I., Golubenko, A., Gothe, R. W., Griffioen, K., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, A., Korover, I., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McCracken, M. E., McKinnon, B., McLauchlin, C., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Pasyuk, E., Pogorelko, O., Prok, Y., Reed, T., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D., Wei, K., Wei, X., Wishart, R., Wood, M. H., Yale, B., Yurov, M., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: Strange matter is believed to exist in the cores of neutron stars based on simple kinematics. If this is true, then hyperon-nucleon interactions will play a significant part in the neutron star equation of state (EOS). Yet, compared to other elastic scattering processes, there is very little data on $\Lambda$-$N$ scattering. This experiment utilized the CLAS detector to study the $\Lambda p \rightarrow \Lambda p$ elastic scattering cross section in the incident $\Lambda$ momentum range 0.9-2.0 GeV/c. This is the first data on this reaction in several decades. The new cross sections have significantly better accuracy and precision than the existing world data, and the techniques developed here can also be used in future experiments., Comment: 6 pages, 5 figures
Published: 2021

24. Deeply virtual Compton scattering using a positron beam in Hall-C at Jefferson Lab

Author: Afanasev, A., Albayrak, I., Ali, S., Amaryan, M., Annand, J. R. M., Asaturyan, A., Bellini, V., Berdnikov, V. V., Boer, M., Brinkmann, K., Briscoe, W. J., Camsonne, A., Caudron, M., Causse, L., Carmignotto, M., Day, D., Defurne, M., Diehl, S., Ent, R., Chatagnon, P., Dupré, R., Dutta, D., Ehrhart, M., Fernando, M. A. I., Forest, T., Guidal, M., Grames, J., Gueye, P., Habet, S., Hamilton, D. J., Hobart, A., Horn, T., Hyde, C., Kalicy, G., Keller, D., Keppel, C., Kerver, M., Kinney, E., Ko, H. -S., Marchand, D., Markowitze, P., Mazouz, M., McCaughan, M., McKinnon, B., Mkrtchyan, A., Mkrtchyan, H., Muhoza, M., Camacho, C. Muñoz, Murphy, J., Nadel-Turonski, P., Niccolai, S., Niculescu, G., Novotny, R., Paremuzyan, R., Pegg, I., Price, K., Rashad, H., Roche, J., Rondon, R., Sawatzky, B., Sergeyeva, V., Širca, S., Somov, A., Strakovsky, I., Tadevosyan, V., Trotta, R., Voskanyan, H., Voutier, E., Wojtsekhowski, B., Wood, S., Zhamkochyan, S., Zhang, J., Zhao, S., and Zorn, C.
Subjects: Nuclear Experiment
Abstract: We propose to use the High Momentum Spectrometer of Hall C combined with the Neutral Particle Spectrometer (NPS) to perform high precision measurements of the Deeply Virtual Compton Scattering (DVCS) cross section using a beam of positrons. The combination of measurements with oppositely charged incident beams is the only unambiguous way to disentangle the contribution of the DVCS$^2$ term in the photon electroproduction cross section from its interference with the Bethe-Heitler amplitude. This provides a stronger way to constrain the Generalized Parton Distributions of the nucleon. A wide range of kinematics accessible with an 11 GeV beam off an unpolarized proton target will be covered. The $Q^2-$dependence of each contribution will be measured independently.
Published: 2021
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25. Beam charge asymmetries for deeply virtual Compton scattering off the proton

Author: Burkert, V., Elouadrhiri, L., Girod, F. -X., Niccolai, S., Voutier, E., Afanasev, A., Barion, L., Battaglieri, M., Bernauer, J. C., Bianconi, A., Capobianco, R., Caudron, M., Causse, L., Chatagnon, P., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Costantini, G., Defurne, M., Deur, A., Diehl, S., Dupré, R., Ehrhart, M., Fernando, I. P., Filippi, A., Forest, T., Grames, J., Gueye, P., Habet, S., Higinbotham, D., Hobart, A., Hyde, C. E., Joo, K., Kim, A., Klimenko, V., Ko, H. -S., Kubarovsky, V., Leali, M., Lenisa, P., Marchand, D., Mascagna, V., McCaughan, M., McKinnon, B., Movsisyan, A., Muñoz~Camacho, C., Pappalardo, L., Pasyuk, E., Poelker, M., Price, K., Raue, B., Shabestari, M., Santos, R., Sergeyeva, V., Strakovsky, I., Stoler, P., Venturelli, L., Zhao, S., Zhao, Z. W., and Collaboration, the CLAS
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The unpolarized and polarized Beam Char\-ge Asymmetries (BCAs) of the $\vv{e}^{\pm}p \to e^{\pm}p \gamma$ process off unpolarized hydrogen are discussed. The measurement of BCAs with the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility, using polarized positron and electron beams at 10.6 GeV is investigated. This experimental configuration allows to measure azimuthal and $t$-dependences of the unpolarized and polarized BCAs over a large $(x_B,Q^2)$ phase space, providing a direct access to the real part of the Compton Form Factor (CFF) ${\mathcal H}$. Additionally, these measurements confront the Bethe-Heitler dominance hypothesis and eventual effects beyond leading twist. The impact of potential positron beam data on the determination of CFFs is also investigated within a local fitting approach of experimental observables. Positron data are shown to strongly reduce correlations between CFFs and consequently improve significantly the determination of $\Re {\rm e} [\mathcal{H}]$., Comment: 11 pages, 10 figures, Article part of the EPJA Topical Issue about "Positron beams and physics at Jefferson Lab". arXiv admin note: text overlap with arXiv:2007.15081
Published: 2021
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26. Measurement of deeply virtual Compton scattering off Helium-4 with CLAS at Jefferson Lab

Author: Dupré, R., Hattawy, M., Baltzell, N. A., Bültmann, S., De Vita, R., Alaoui, A. El, Fassi, L. El, Egiyan, H., Girod, F. X., Guidal, M., Hafidi, K., Jenkins, D., Liuti, S., Perrin, Y., Stepanyan, S., Torayev, B., Voutier, E., Amaryan, M. J., Armstrong, W. R., Atac, H., Gayoso, C. Ayerbe, Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W. J., Bulumulla, D., Burkert, V., Carman, D. S., Carvajal, J. C., Caudron, M., Celentano, A., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clary, B. A., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., Defurne, M., Deur, A., Diehl, S., Djalali, C., Ehrhart, M., Elouadrhiri, L., Eugenio, P., Fegan, S., Filippi, A., Forest, T. A., Ghandilyan, Y., Gilfoyle, G. P., Gothe, R. W., Griffioen, K. A., Hakobyan, H., Hayward, T. B., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, G., Khanal, A., Khandaker, M., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Livingston, K., Kabir, M. L., Leali, M., Lenisa, P., MacGregor, I. J. D., Marchand, D., Markov, N., Mascagna, V., Mayer, M., McKinnon, B., Mirazita, M., Mokeev, V. I., Neupane, K., Niccolai, S., O'Connell, T. R., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Payette, D., Phelps, W., Pivnyuk, N., Pogorelko, O., Poudel, J., Prok, Y., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rossi, P., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Schumacher, R., Sergeyeva, V., Sharabian, Y., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Watts, D., Wei, K., Wei, X., Weinstein, L. B., Wishart, R., Wood, M. H., Yale, B., Zachariou, N., and Zhang, J.
Subjects: Nuclear Experiment
Abstract: We report on the measurement of the beam spin asymmetry in the deeply virtual Compton scattering off $^4$He using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab using a 6 GeV longitudinally polarized electron beam incident on a pressurized $^4$He gaseous target. We detail the method used to ensure the exclusivity of the measured reactions, in particular the upgrade of CLAS with a radial time projection chamber to detect the low-energy recoiling $^4$He nuclei and an inner calorimeter to extend the photon detection acceptance at forward angles. Our results confirm the theoretically predicted enhancement of the coherent ($e^4$He$~\to~e'$$^4$He$'\gamma'$) beam spin asymmetries compared to those observed on the free proton, while the incoherent ($e^4$He$~\to~e'$p$'\gamma'$X$'$) asymmetries exhibit a 30$\%$ suppression. From the coherent data, we were able to extract, in a model-independent way, the real and imaginary parts of the only $^4$He Compton form factor, $\cal H_A$, leading the way toward 3D imaging of the partonic structure of nuclei.
Published: 2021
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27. Measurement of the proton spin structure at long distances

Author: Zheng, X., Deur, A., Kang, H., Kuhn, S. E., Ripani, M., Zhang, J., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Atac, H., Avakian, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boiarinov, S., Bondi, M., Bossu, F., Bosted, P., Briscoe, W. J., Brock, J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carlin, C., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Chen, J. -P., Choi, S., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Drozdov, V. A., Dupre, R., Ehrhart, M., Alaoui, A. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Forest, T. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. -X., Glazier, D. I., Gothe, R. W., Griffioen, K. A., Guidal, M., Guler, N., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holmstrom, T., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keith, C. D., Keller, D., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., livingston, K., Long, E., MacGregor, I. J. D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meekins, D. G., Mineeva, T., Mirazita, M., Mokeev, V., Mullen, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L., Park, K., Pasyuk, E., Phelps, W., Phillips, S. K., Pogorelko, O., Poudel, J., Prok, Y., Raue, B. A., Ritman, J., Rizzo, A., Rosner, G., Rossi, P., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Seely, M. L., Sharabian, Y. G., Shrestha, U., Sirca, S., Slifer, K., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Sulkosky, V., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Yale, B., Zachariou, N., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Measuring the spin structure of protons and neutrons tests our understanding of how they arise from quarks and gluons, the fundamental building blocks of nuclear matter. At long distances the coupling constant of the strong interaction becomes large, requiring non-perturbative methods to calculate quantum chromodynamics processes, such as lattice gauge theory or effective field theories. Here we report proton spin structure measurements from scattering a polarized electron beam off polarized protons. The spin-dependent cross-sections were measured at large distances, corresponding to the region of low momentum transfer squared between 0.012 and 1.0 GeV$^2$. This kinematic range provides unique tests of chiral effective field theory predictions. Our results show that a complete description of the nucleon spin remains elusive, and call for further theoretical works, e.g. in lattice quantum chromodynamics. Finally, our data extrapolated to the photon point agree with the Gerasimov-Drell-Hearn sum rule, a fundamental prediction of quantum field theory that relates the anomalous magnetic moment of the proton to its integrated spin-dependent cross-sections., Comment: Published version. 10 pages, 5 figures. 20 pages of supplementary material (data tables and a figure)
Published: 2021
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28. Differential cross sections for {\Lambda}(1520) using photoproduction at CLAS

Author: Shrestha, U., Chetry, T., Djalali, C., Hicks, K., Nam, S. i., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Ciullo, G., Cole, P. L., Contalbrigo, M., Crede, V., De Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Holtrop, M., Huang, Q., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Marsicano, L., Mascagna, V., McCracken, M. E., McKinnon, B., Mokeev, V., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Turonski, P. Nadel, Neupane, 5 K., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pivnyuk, N., Pogorelko, O., Poudel, J., Prok, Y., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment
Abstract: The reaction $\gamma p \rightarrow K^{+} \Lambda(1520)$ using photoproduction data from the CLAS $g12$ experiment at Jefferson Lab is studied. The decay of $\Lambda(1520)$ into two exclusive channels, $\Sigma^{+}\pi^{-}$ and $\Sigma^{-}\pi^{+}$, is studied from the detected $K^{+}$, $\pi^{+}$, and $\pi^{-}$ particles. A good agreement is established for the $\Lambda(1520)$ differential cross sections with the previous CLAS measurements. The differential cross sections as a function of CM angle are extended to higher photon energies. Newly added are the differential cross sections as a function of invariant 4-momentum transfer $t$, which is the natural variable to use for a theoretical model based on a Regge-exchange reaction mechanism. No new $N^*$ resonances decaying into the $K^+\Lambda(1520)$ final state are found., Comment: 16 pages, 12 figures, 2 tables
Published: 2021
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29. Observation of Beam Spin Asymmetries in the Process $e p \rightarrow e \pi^{+}\pi^{-}X$ with CLAS12

Author: Hayward, T. B., Dilks, C., Vossen, A., Avakian, H., Adhikari, S., Angelini, G., Arratia, M., Atac, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondì, M., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B. A., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Dugger, M., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T. A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hicks, K., Hobart, A., Holtrop, M., Ireland, D. G., Isupov, E. L., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meziani, Z. E., Mirazita, M., Mokeev, V., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Nanda, S., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Prok, Y., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Segarra, E. P., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Thornton, A., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., and Zhang, J.
Subjects: High Energy Physics - Experiment
Abstract: The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6 GeV longitudinally spin-polarized electron beam delivered by CEBAF at JLab. The measured asymmetries provide the first opportunity to extract the parton distribution function $e(x)$, which provides information about the interaction between gluons and quarks, in a collinear framework that offers cleaner access than previous measurements. The asymmetries also constitute the first ever signal sensitive to the helicity-dependent two-pion fragmentation function $G_1^\perp$. A clear sign change is observed around the $\rho$ mass that appears in model calculations and is indicative of the dependence of the produced pions on the helicity of the fragmenting quark., Comment: 6 pages, 5 figures
Published: 2021
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30. Multidimensional, high precision measurements of beam single spin asymmetries in semi-inclusive $\pi^{+}$ electroproduction off protons in the valence region

Author: Diehl, S., Kim, A., Angelini, G., Joo, K., Adhikari, S., Amaryan, M., Arratia, M., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Bastami, S., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bondi, M., Bossu, F., Boiarinov, S., Brinkmann, K. -T., Briscoe, W. J., Brooks, W., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Costantini, G., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Dilks, C., Djalali, C., Dugger, M., Dupre, R., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Fegan, S., Filippi, A., Forest, T., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golubenko, A. A., Gothe, R. W., Gotra, Y., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Hyde, C. E., Ireland, D. G., Isupov, E. L., Jo, H. S., Johnston, R., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Kim, W., Kripko, A., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lee, S., Lenisa, P., Livingston, K., Lu, Z., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meziani, Z. E., Milner, R. G., Mineeva, T., Mirazita, M., Mokeev, V., Moran, P., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Niccolai, S., Niculescu, G., O'Connell, T. R., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Prok, Y., Prokudin, A., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Roberts, C. D., Rossi, P., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Segarra, E. P., Sharabian, Y. G., Shrestha, U., Simmerling, P., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Tezgin, K., Thornton, A., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D. P., Wei, K., Wei, X., Xu, S. -S., Yale, B., Zachariou, N., and Zhang, J.
Subjects: High Energy Physics - Experiment
Abstract: High precision measurements of the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering (SIDIS) from the proton have been performed using a 10.6~GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. We report here a high precision multidimensional study of single $\pi^{+}$ SIDIS data over a large kinematic range in Bjorken x, fractional energy and transverse momentum of the hadron as well as photon virtualities $Q^{2}$ ranging from $1-7\,$GeV$^{2}$. In particular, the structure function ratio $F^{\sin\phi}_{LU}/F_{UU}$ has been determined, where $F^{\sin\phi}_{LU}$ is a twist-3 quantity that can reveal novel aspects of emergent hadron mass and quark-gluon correlations within the nucleon. The data's impact on the evolving understanding of the underlying reaction mechanisms and their kinematic variation is explored using theoretical models for the different contributing transverse momentum dependent parton distribution functions.
Published: 2021
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31. Photoproduction of the $f_2(1270)$ meson using the CLAS detector

Author: Carver, M., Celentano, A., Hicks, K., Marsicano, L., Mathieu, V., Pilloni, A., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, Giovanni, Atac, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biselli, A. S., Bondi, M., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De~Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., El~Alaoui, A., El~Fassi, L., Eugenio, P., Fedotov, G., Fegan, S., Filippi, A., Gavalian, G., Gevorgyan, N., Gilfoyle, G. P., Girod, F. X., Gothe, R. W., Griffioen, K. A., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Holtrop, M., Huang, Q., Hyde, C. E., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Joosten, S. ~, Keller, D., Khanal, A., Khandaker, M., Kim, A., Kim, C. W., Klein, F. J., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Mascagna, V., McCracken, M. E., McKinnon, B., Meziani, Z. E., Mokeev, V., A~Movsisyan, Munevar, E., Munoz~Camacho, C., Nadel-Turonski, P., Neupane, K., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Prok, Y., Protopopescu, D., Ripani, M., Ritchie, B. G., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatié, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyler, N., Tyson, R., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: The quark structure of the $f_2(1270)$ meson has, for many years, been assumed to be a pure quark-antiquark ($q\bar{q}$) resonance with quantum numbers $J^{PC} = 2^{++}$. Recently, it was proposed that the $f_2(1270)$ is a molecular state made from the attractive interaction of two $\rho$-mesons. Such a state would be expected to decay strongly to final states with charged pions, due to the dominant decay $\rho \to \pi^+ \pi^-$, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction $\gamma p \to \pi^0 \pi^0 p$, using the CLAS detector at Jefferson Lab for incident beam energies between 3.6-5.4~GeV. Differential cross sections, $d\sigma / dt$, for $f_2(1270)$ photoproduction are extracted with good precision, due to low backgrounds, and are compared with theoretical calculations., Comment: 5 pages, 4 figures
Published: 2020
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32. Beam spin asymmetry in semi-inclusive electroproduction of a hadron pair

Author: Mirazita, M., Avakian, H., Courtoy, A., Pisano, S., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, Fatiha, Bianconi, A., Biselli, A. S., Bossu', F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fegan, S., Fersch, R., Filippi, A., Forest, T. A., Ghandilyan, Y., Gavalian, G., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Huang, Q., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I . J . D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Milner, R. G., Mineeva, T., Mokeev, V., Mullen, C., Camacho, C. Munoz, Neupane, K., Niculescu, G., O'Connell, T., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pocanic, D., Pogorelko, O., Poudel, J., Prok, Y., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rossi, P., Sabatie', F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Vossen, A., Voutier, E., Watts, D., Wei, K., Wei, X., Wood, M. H., Yale, B., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: A first measurement of the longitudinal beam spin asymmetry ALU in the semi-inclusive electroproduction of pairs of charged pions is reported. ALU is a higher-twist observable and offers the cleanest access to the nucleon twist-3 parton distribution function e(x). Data have been collected in the Hall-B at Jefferson Lab by impinging a 5.498 GeV electron beam on a liquid-hydrogen target, and reconstructing the scattered electron and the pion pair with the CLAS detector. One-dimensional projections of the sin(phiR) moments of ALU are extracted for the kinematic variables of interest in the valence quark region. The understanding of di-hadron production is essential for the interpretation of observables in single hadron production in semi-inclusive DIS, and pioneering measurements of single spin asymmetries in di-hadron production open a new avenue in studies of QCD dynamics.
Published: 2020
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33. Studying Short-Range Correlations with Real Photon Beams at GlueX

Author: Hen, O., Patsyuk, M., Piasetzky, E., Schmidt, A., Somov, A., Szumila-Vance, H., Weinstein, L. B., Dutta, D., Gao, H., Amaryan, M., Ashkenazi, A., Beck, A., Berdnikov, V., Black, T., Briscoe, W. J., Britton, T., Brooks, W., Cruz-Torres, R., Dalton, M. M., Denniston, A., Deur, A., Egiyan, H., Fanelli, C., Fegan, S., Furletov, S., Gan, L., Guo, L., Hauenstein, F., Haykobyan, H., Higinbotham, D. W., Ireland, D. G., Johansson, G., Kamel, M., Korover, I., Kuleshov, S., Lawrence, D., Livingston, K., Mack, D., Marukyan, H., McCaughan, M., Mckinnon, B., Meytal-Beck, S., Nerline, F., Nguyen, D., Papadopoulou, A., Pauli, P., Pedroni, R., Pentchev, L., Pybus, J. R., Ratliff, S., Romanov, D., Romera, C., Salgado, C., Schmookler, B., Segarra, E. P., Seroka, E., Sharp, P., Somov, S., Strakovsky, I. I., Taylor, S., Thiel, A., and Zihlmann, B.
Subjects: Nuclear Experiment
Abstract: The past few years has seen tremendous progress in our understanding of short-range correlated (SRC) pairing of nucleons within nuclei, much of it coming from electron scattering experiments leading to the break-up of an SRC pair. The interpretation of these experiments rests on assumptions about the mechanism of the reaction. These assumptions can be directly tested by studying SRC pairs using alternate probes, such as real photons. We propose a 30-day experiment using the Hall D photon beam, nuclear targets, and the GlueX detector in its standard configuration to study short-range correlations with photon-induced reactions. Several different reaction channels are possible, and we project sensitivity in most channels to equal or exceed the 6 GeV-era SRC experiments from Halls A and B. The proposed experiment will therefore decisively test the phenomena of np dominance, the short-distance NN interaction, and reaction theory, while also providing new insight into bound nucleon structure and the onset of color transparency., Comment: 38 pages, 26 figures, proposal for Jefferson Lab Experiment E12-19-003, submitted to Jefferson Lab PAC 47 (2019)
Published: 2020

34. Extraction of beam-spin asymmetries from the hard exclusive $\pi^{+}$ channel off protons in a wide range of kinematics

Author: Diehl, S., Joo, K., Kim, A., Avakian, H., Kroll, P., Park, K., Riser, D., Semenov-Tian-Shansky, K., Tezgin, K., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Asryan, G., Atac, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Boss`u, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Bulumulla, D., Burkert, V. D., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Dilks, C., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Filippi, A., Forest, T. A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hakobyan, H., Harrison, N., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Kubarovsky, V., Kuhn, S. E., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., McKinnon, B., Meziani, Z. E., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Niculescu, G., Osipenko, M., Paolone, M., Pappalardo, L. L., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Raue, B. A., Ripani, M., Rizzo, A., Rossi, P., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: We have measured beam-spin asymmetries to extract the $\sin\phi$ moment $A_{LU}^{\sin\phi}$ from the hard exclusive $\vec{e} p \to e^\prime n \pi^+$ reaction above the resonance region, for the first time with nearly full coverage from forward to backward angles in the center-of-mass. The $A_{LU}^{\sin\phi}$ moment has been measured up to 6.6 GeV$^{2}$ in $-t$, covering the kinematic regimes of Generalized Parton Distributions (GPD) and baryon-to-meson Transition Distribution Amplitudes (TDA) at the same time. The experimental results in very forward kinematics demonstrate the sensitivity to chiral-odd and chiral-even GPDs. In very backward kinematics where the TDA framework is applicable, we found $A_{LU}^{\sin\phi}$ to be negative, while a sign change was observed near 90$^\circ$ in the center-of-mass. The unique results presented in this paper will provide critical constraints to establish reaction mechanisms that can help to further develop the GPD and TDA frameworks.
Published: 2020
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35. 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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36. Photoproduction of $\eta$ mesons off the proton for $1.2 < E_\gamma < 4.7$ GeV using CLAS at Jefferson Laboratory

Author: Hu, T., Akbar, Z., Crede, V., Adhikari, K. P., Adhikari, S., Amaryan, M. J., Angelini, G., Asryan, G., Atac, H., Gayoso, C. Ayerbe, Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bossu, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Carman, D. S., Carvajal, J., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Cruz-Torres, R., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Gavalian, G., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Hobart, A., Holtrop, M., Ilieva, Y., Illari, I., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Joosten, S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Mascagna, V., McCracken, M. E., McKinnon, B., Meyer, C. A., Meziani, Z. E., Mineeva, T., Mokeev, V., Movsisyan, A., Munevar, E., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Phelps, W., Pogorelko, O., Poudel, J., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Ritman, J., Rizzo, A., Rosner, G., Rowley, J., Sabatie, F., Salgado, C., Schmidt, A., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Skorodumina, Iu., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, K., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Photoproduction cross sections are reported for the reaction $\gamma p\to p\eta$ using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The $\eta$ mesons are detected in their dominant charged decay mode, $\eta\to \pi^+\pi^-\pi^0$, and results on differential cross sections are presented for incident photon energies between 1.2 and 4.7 GeV. These new $\eta$ photoproduction data are consistent with earlier CLAS results but extend the energy range beyond the nucleon resonance region into the Regge regime. The normalized angular distributions are also compared with the experimental results from several other experiments, and with predictions of $\eta$ MAID\,2018 and the latest solution of the Bonn-Gatchina coupled-channel analysis. Differential cross sections $d\sigma/dt$ are presented for incident photon energies $E_\gamma > 2.9$ GeV ($W > 2.5$ GeV), and compared with predictions which are based on Regge trajectories exchange in the $t$-channel (Regge models). The data confirm the expected dominance of $\rho$, $\omega$ vector-meson exchange in an analysis by the Joint Physics Analysis Center., Comment: 24 pages, 22 figures
Published: 2020
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37. Probing the core of the strong nuclear interaction

Author: Schmidt, A., Pybus, J. R., Weiss, R., Segarra, E. P., Hrnjic, A., Denniston, A., Hen, O., Piasetzky, E., Weinstein, L. B., Barnea, N., Strikman, M., Larionov, A., Higinbotham, D., Adhikari, S., Amaryan, M., Angelini, G., Asryan, G., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Baashen, L., Barion, L., Bashkanov, M., Battaglieri, M., Beck, A., Bedlinskiy, I., Benmokhtar, F., Bianconi, A., Biselli, A. S., Bossu, F., Biarinov, S., Briscoe, W. J., Brooks, W., Burkert, V. D., Cao, F., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cohen, E., Cole, P. L., Contalbrigo, M., Crede, V., Cruz-Torres, R., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Duer, M., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Filippi, A., Forest, T. A., Gavalian, G., Gilad, S., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Giuseppe, C., Glazier, D. I., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Hauenstein, F., Hayward, T. B., Hicks, K., Holtrop, M., Ilieva, Y., Illari, I., Ireland, D., Ishkanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Joo, K., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., Korover, I., Kubarovsky, V., Lanza, L., Leali, M., Lenisa, P., MacGregor, I. J. D., Marchand, D., Markov, N., Marsicano, L., Mascagna, V., Beck, S. May-Tal, McKinnon, B., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Mustapha, B., Nadel-Turonski, P., Nanda, S., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Patsyuk, M., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Sabatie, F., Salgado, C., Schmookler, B., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Skorodumina, Iu., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Tyler, N., Ungaro, M., Venturelli, L., Voskanyan, H., Voutier, E., Wang, R., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zheng, X.
Subjects: Nuclear Experiment, Nuclear Theory
Abstract: The strong nuclear interaction between nucleons (protons and neutrons) is the effective force that holds the atomic nucleus together. This force stems from fundamental interactions between quarks and gluons (the constituents of nucleons) that are described by the equations of Quantum Chromodynamics (QCD). However, as these equations cannot be solved directly, physicists resort to describing nuclear interactions using effective models that are well constrained at typical inter-nucleon distances in nuclei but not at shorter distances. This limits our ability to describe high-density nuclear matter such as in the cores of neutron stars. Here we use high-energy electron scattering measurements that isolate nucleon pairs in short-distance, high-momentum configurations thereby accessing a kinematical regime that has not been previously explored by experiments, corresponding to relative momenta above 400 MeV/c. As the relative momentum between two nucleons increases and their separation thereby decreases, we observe a transition from a spin-dependent tensor-force to a predominantly spin-independent scalar-force. These results demonstrate the power of using such measurements to study the nuclear interaction at short-distances and also support the use of point-like nucleons with two- and three-body effective interactions to describe nuclear systems up to densities several times higher than the central density of atomic nuclei., Comment: Total 26 pages, 13 figures. Main text: 8 pages, 3 figures. Methods section: 6 pages. Extended Data: 8 figures, 1 table. Supplementary Materials: 8 pages, 2 figures
Published: 2020
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38. Measurement of the helicity asymmetry Eγ→p→→pπ0 for the Eγ→p→→pπ0 reaction in the resonance region: The CLAS Collaboration

Author: Kim, C. W., Zachariou, N., Bashkanov, M., Briscoe, W. J., Fegan, S., Kashevarov, V. L., Nikonov, K., Sarantsev, A., Schmidt, A., Strakovsky, I. I., Watts, D. P., Workman, R. L., Achenbach, P., Akbar, Z., Amaryan, M. J., Angelini, G., Armstrong, W. R., Atac, H., Baashen, L., Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Benmouna, N., Bianconi, A., Biselli, A. S., Booth, W. A., Bossù, F., Boiarinov, S., Brinkmann, K. T., Brock, J., Bulumulla, D., Burkert, V. D., Cao, T., Carlin, C., Carman, D. S., Carvajal, J. C., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Clash, G., Cole, P. L., Contalbrigo, M., Becerra, O. Cortes, Costantini, G., Crede, V., D’Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Filippi, A., Fogler, C., Gavalian, G., Gilfoyle, G. P., Golubenko, A. A., Gosta, G., Gothe, R. W., Griffioen, K. A., Hafidi, K., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T. B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Illari, I., Ireland, D. G., Isupov, E. L., Iwamoto, H., Jenkins, D., Jo, H. S., Johnston, R., Joo, K., Joosten, S., Kageya, T., Keith, C. D., Keller, D., Khanal, A., Kim, A., Kim, W., Klein, F. J., Klimenko, V., Kripko, A., Kubarovsky, V., Lanza, L., Leali, M., Lee, S., Li, X., Livingston, K., MacGregor, I. J. D., Marchand, D., Mascagna, V., McKinnon, B., Migliorati, S., Milner, R. G., Mineeva, T., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Neupane, K., Niccolai, S., Osipenko, M., Ostrovidov, A. I., Pandey, P., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Paul, S. J., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Prok, Y., Radic, A., Ramasubramanian, N., Ratliff, S., Reed, T., Richards, J., Ripani, M., Ritchie, B. G., Ritman, J., Rosner, G., Salgado, C., Schadmand, S., Schott, D., Schumacher, R. A., Scott, M. B. C., Seely, M. L., Seroka, E. M., Shirokov, E. V., Shrestha, U., Sokhan, D., Sparveris, N., Spreafico, M., Strauch, S., Tan, J., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Wei, X., Williams, R., Wishart, R., Wood, M. H., Yurov, M., Zhang, J., and Zurek, M.
Published: 2023
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39. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab -- 2018 update to PR12-16-001

Author: Battaglieri, M., Bersani, A., Bracco, G., Caiffi, B., Celentano, A., De Vita, R., Marsicano, L., Musico, P., Panza, F., Ripani, M., Santopinto, E., Taiuti, M., Bellini, V., Bondi', M., Castorina, P., De Napoli, M., Italiano, A., Kuznetzov, V., Leonora, E., Mammoliti, F., Randazzo, N., Re, L., Russo, G., Russo, M., Shahinyan, A., Sperduto, M., Spinali, S., Sutera, C., Tortorici, F., Baltzell, N., Dalton, M., Freyberger, A., Girod, F. -X., Kharashvili, G., Kubarovsky, V., Pasyuk, E., Smith, E. S., Stepanyan, S., Szumilla-Vance, H., Ungaro, M., Whitlatch, T., Izaguirre, E., Krnjaic, G., Ehle, I., Snowden-Ifft, D., Loomba, D., Carpinelli, M., D'Urso, D., Gabrieli, A., Maccioni, G., Sant, M., Sipala, V., Ameli, F., Cisbani, E., De Persio, F., Del Dotto, A., Garibaldi, F., Meddi, F., Nicolau, C. A., Urciuoli, G. M., Chiarusi, T., Manzali, M., Pellegrino, C., Schuster, P., Toro, N., Essig, R., Wood, M. H., Holtrop., M., Paremuzyan, R., De Cataldo, G., De Leo, R., Di Bari, D., Lagamba, L., Nappi, E., Perrino, R., Balossino, I., Barion, L., Ciullo, G., Contalbrigo, M., Drago, A., Lenisa, P., Movsisyan, A., Pappalardo, L., Spizzo, F., Turisini, M., Hasch, D., Lucherini, V., Mirazita, M., Pisano, S., Rossi, P., Tomassini, S., Simi, G., D'Angelo, A., Lanza, L., Rizzo, A., Filippi, A., Genovese, M., Kunkel, M., Bashkanov, M., Murphy, A., Smith, G., Watts, D., Zachariou, N., Zana, L., Glazier, D., Ireland, D., McKinnon, B., Sokhan, D., Colaneri, L., Pereira, S. Anefalos, Afanasev, A., Briscoe, B., Strakovsky, I., Kalantarians, N., Weinstein, L., Adhikari, K. P., Dunne, J. A., Dutta, D., Fassi, L. El, Ye, L., Hicks, K., Cole, P., Dobbs, S., Fanelli, C., and Mohanmurthy, P.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: This document complements and completes what was submitted last year to PAC45 as an update to the proposal PR12-16-001 "Dark matter search in a Beam-Dump eXperiment (BDX)" at Jefferson Lab submitted to JLab-PAC44 in 2016. Following the suggestions contained in the PAC45 report, in coordination with the lab, we ran a test to assess the beam-related backgrounds and validate the simulation framework used to design the BDX experiment. Using a common Monte Carlo framework for the test and the proposed experiment, we optimized the selection cuts to maximize the reach considering simultaneously the signal, cosmic-ray background (assessed in Catania test with BDX-Proto) and beam-related backgrounds (irreducible NC and CC neutrino interactions as determined by simulation). Our results confirmed what was presented in the original proposal: with 285 days of a parasitic run at 65 $\mu$A (corresponding to $10^{22}$ EOT) the BDX experiment will lower the exclusion limits in the case of no signal by one to two orders of magnitude in the parameter space of dark-matter coupling versus mass.
Published: 2019

40. Deep learning level-3 electron trigger for CLAS12

Author: Tyson, R., Gavalian, G., Ireland, D.G., and McKinnon, B.
Published: 2023
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41. Exclusive $\bm{\pi^{0}p}$ electroproduction off protons in the resonance region at photon virtualities 0.4~GeV$\bm{^{2}}$ $\bm{\leq~ Q^{2} \leq~1}$~GeV$\bm{^{2}}$

Author: Markov, N., Joo, K., Burkert, V. D., Mokeev, V. I., Smith, L. C., Ungaro, M., Adhikari, S., Amaryan, M. J., Angelini, G., Atac, H., Avakian, H., Gayoso, C. Ayerbe, Baltzell, N. A., Barion, L., Battaglieri, M., Bedlinskiy, I., Benmokhtar, F., Biselli, A. S., Bossù, F., Boiarinov, S., Briscoe, W. J., Brooks, W. K., Carman, D. S., Carvajal, J. C., Celentano, A., Chatagnon, P., Chetry, T., Cole, P. L., Contalbrigo, M., Crede, V., Ciullo, G., D'Angelo, A., Dashyan, N., De~Vita, R., De~Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dupre, R., Ehrhart, M., El~Alaoui, A., El~Fassi, L., Eugenio, P., Evans, C., Filippi, A., Ghandilyan, Y., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Hattawy, M., Hayward, T. B., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Keller, D., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Lanza, L., Leali, M., Livingston, K., MacGregor, I . J . D., Marchand, D., Mascagna, V., McKinnon, B., Mineeva, T., Mirazita, M., Nadel-Turonski, P., Nanda, S., Niccolai, S., Niculescu, G., Osipenko, M., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rowley, J., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Shrestha, U., Sokhan, D., Soto, O., Sparveris, N., Stepanyan, S., Stoler, P., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Tyler, N., Venturelli, L., Voskanyan, H., Voutier, E., Wang, R., Wei, X., Wood, M. H., and Zachariou, N.
Subjects: Nuclear Experiment
Abstract: The exclusive electroproduction process $ep \rightarrow e'p'\pi^{0}$ was measured in the range of photon virtualities $Q^{2} = 0.4 - 1.0$~GeV$^{2}$ and the invariant mass range of the $p\pi^{0}$ system of $W = 1.1 - 1.8$~GeV. These kinematics are covered in exclusive $\pi^{0}$ electroproduction off the proton with nearly complete angular coverage in the $p\pi^{0}$ center-of-mass system and with high statistical accuracy. Nearly 36000 cross section points were measured, and the structure functions $\sigma_T+\epsilon\sigma_L$, $\sigma_{LT}$, and $\sigma_{TT}$, were extracted via fitting the $\phi_{\pi^{0}}$ dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying $N^*$ and $\Delta^{*}$ resonances with $M~>~1.6$ GeV. As part of a broad effort to determine the electrocouplings of the $N^{*}$ and $\Delta^{*}$ resonances using both single- and double-pion electroproduction, this dataset is crucial for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the $N \pi$ and $\pi^{+}\pi^{-} p$ channels., Comment: 21 pages, 24 figures
Published: 2019
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42. Physics with Positron Beams at Jefferson Lab 12 GeV

Author: Afanasev, A., Albayrak, I., Ali, S., Amaryan, M., D'Angelo, A., Annand, J., Arrington, J., Asaturyan, A., Avakian, H., Averett, T., Barion, L., Battaglieri, M., Bellini, V., Berdnikov, V., Bernauer, J., Biselli, A., Boer, M., Bondì, M., Brinkmann, K. -T., Briscoe, B., Burkert, V., Camsonne, A., Cao, T., Cardman, L., Carmignotto, M., Causse, L., Celentano, A., Chatagnon, P., Ciullo, G., Contalbrigo, M., Day, D., Defurne, M., Diehl, S., Dongwi, B., Dupré, R., Dutta, D., Ehrhart, M., Elouadrhiri, L., Ent, R., Fernando, I., Filippi, A., Furletova, Y., Gao, H., Gasparian, A., Gaskell, D., Georges, F., Girod, F. -X., Grames, J., Gu, C., Guidal, M., Hamilton, D., Hasell, D., Higinbotham, D., Hoballah, M., Horn, T., Hyde, C., Italiano, A., Kalantarians, N., Kalicy, G., Keller, D., Keppel, C., Kerver, M., King, P., Kinney, E., Ko, H. -S., Kohl, M., Kubarovsky, V., Lanza, L., Lenisa, P., Liyanage, N., Liuti, S., Mamei, J., Marchand, D., Markowitz, P., Marsicano, L., Mazouz, M., McCaughan, M., McKinnon, B., Mihovilovič, M., Milner, R., Mkrtchyan, A., Mkrtchyan, H., Movsisyan, A., Camacho, C. Muñoz, Nadel-Turońs, P., De Napoli, M., Nazeer, J., Niccolai, S., Niculescu, G., Novotny, R., Pappalardo, L., Paremuzyan, R., Pasyuk, E., Patel, T., Pegg, I., Perera, D., Puckett, A., Randazzo, N., Rashad, M., Rathnayake, M., Rizzo, A., Roche, J., Rondon, O., Schmidt, A., Shabestari, M., Sharabian, Y., Širca, S., Sokhan, D., Somov, A., Sparveris, N., Stepanyan, S., Strakovsky, I., Tadevosyan, V., Tiefenback, M., Trotta, R., De Vita, R., Voskanyan, H., Voutier, E., Wang, R., Wojtsekhowski, B., Wood, S., Zaunick, H. -G., Zhamkochyan, S., Zhang, J., Zhao, S., Zheng, X., and Zorn, C.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: Positron beams, both polarized and unpolarized, are identified as essential ingredients for the experimental program at the next generation of lepton accelerators. In the context of the Hadronic Physics program at the Jefferson Laboratory (JLab), positron beams are complementary, even essential, tools for a precise understanding of the electromagnetic structure of the nucleon, in both the elastic and the deep-inelastic regimes. For instance, elastic scattering of (un)polarized electrons and positrons off the nucleon allows for a model independent determination of the electromagnetic form factors of the nucleon. Also, the deeply virtual Compton scattering of (un)polarized electrons and positrons allows us to separate unambiguously the different contributions to the cross section of the lepto-production of photons, enabling an accurate determination of the nucleon Generalized Parton Distributions (GPDs), and providing an access to its Gravitational Form Factors. Furthermore, positron beams offer the possibility of alternative tests of the Standard Model through the search of a dark photon or the precise measurement of electroweak couplings. This letter proposes to develop an experimental positron program at JLab to perform unique high impact measurements with respect to the two-photon exchange problem, the determination of the proton and the neutron GPDs, and the search for the $A^{\prime}$ dark photon., Comment: Letter-of-Intent to Jefferson Lab PAC46
Published: 2019

43. Alignment of the CLAS12 central hybrid tracker with a Kalman Filter

Author: Paul, S.J., Peck, A., Arratia, M., Gotra, Y., Ziegler, V., De Vita, R., Bossù, F., Defurne, M., Atac, H., Gayoso, C. Ayerbe, Baashen, L., Baltzell, N.A., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bianconi, A., Biondo, L., Biselli, A.S., Bondi, M., Boiarinov, S., Brinkmann, K.-Th., Briscoe, W.J., Brooks, W.K., Bulumulla, D., Burkert, V.D., Capobianco, R., Carman, D.S., Carvajal, J.C., Chatagnon, P., Chesnokov, V., Chetry, T., Ciullo, G., Cole, P.L., Costantini, G., D’Angelo, A., Dashyan, N., Deur, A., Diehl, S., Djalali, C., Dupre, R., El Alaoui, A., El Fassi, L., Elouadrhiri, L., Filippi, A., Gates, K., Gavalian, G., Ghandilyan, Y., Gilfoyle, G.P., Golubenko, A.A., Gosta, G., Gothe, R.W., Griffioen, K., Guidal, M., Hakobyan, H., Hattawy, M., Hauenstein, F., Hayward, T.B., Heddle, D., Hobart, A., Holtrop, M., Ilieva, Y., Ireland, D.G., Isupov, E.L., Jo, H.S., Johnston, R., Joo, K., Keller, D., Khachatryan, M., Khanal, A., Kim, A., Kim, W., Klimenko, V., Kripko, A., Lanza, L., Leali, M., Lenisa, P., Li, X., MacGregor, I.J.D., Marchand, D., Marsicano, L., Mascagna, V., McKinnon, B., McLauchlin, C., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Camacho, C. Munoz, Nadel-Turonski, P., Naidoo, P., Neupane, K., Nguyen, D., Niccolai, S., Nicol, M., Niculescu, G., Osipenko, M., Pandey, P., Paolone, M., Paremuzyan, R., Pilleux, N., Pogorelko, O., Pokhrel, M., Poudel, J., Price, J.W., Prok, Y., Reed, T., Ripani, M., Ritman, J., Sabatié, F., Schadmand, S., Schmidt, A., Shirokov, E.V., Shrestha, U., Simmerling, P., Sokhan, D., Sparveris, N., Spreafico, M., Strakovsky, I.I., Strauch, S., Tan, J.A., Tyson, R., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D.P., Wei, X., Wishart, R., Wood, M.H., and Zachariou, N.
Published: 2023
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44. Exploring the Structure of the Bound Proton with Deeply Virtual Compton Scattering

Author: Hattawy, M., Baltzell, N. A., Dupré, R., Bültmann, S., De Vita, R., Alaoui, A. El, Fassi, L. El, Egiyan, H., Girod, F. X., Guidal, M., Hafidi, K., Jenkins, D., Liuti, S., Perrin, Y., Stepanyan, S., Torayev, B., Voutier, E., Adhikari, S., Angelini, Giovanni, Gayoso, C. Ayerbe, Barion, L., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Bossù, F., Brooks, W., Cao, F., Carman, D. S., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Ehrhart, M., Eugenio, P., Fegan, S., Filippi, A., Forest, T. A., Fradi, A., Garçon, M., Gavalian, G., Gevorgyan, N., Gilfoyle, G. P., Giovanetti, K. L., Golovatch, E., Gothe, R. W., Griffioen, K. A., Harrison, N., Hauenstein, F., Hayward, T. B., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Johnston, S., Keller, D., Khachatryan, G., Khachatryan, M., Khanal, A., Khandaker, M., Kim, C. W., Kim, W., Klein, F. J., Kubarovsky, V., Kuhn, S. E., Lanza, L., Kabir, M. L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., Mayer, M., McKinnon, B., Meziani, Z. E., Mineeva, T., Mirazita, M., Montgomery, R. A., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Ostrovidov, A. I., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Pogorelko, O., Poudel, J., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Rossi, P., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Sokhan, D., Soto, O., Sparveris, N., Strauch, S., Taiuti, M., Tan, J. A., Tyler, N., Ungaro, M., Voskanyan, H., Wang, R., Watts, D. P., Wei, X., Weinstein, L. B., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this work, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering (DVCS) off a proton bound in $^4$He. The data used here were accumulated using a $6$ GeV longitudinally polarized electron beam incident on a pressurized $^4$He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle ($\phi$) dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The $Q^2$, $x_B$, and t dependencies of the BSA on the bound proton are compared with those on the free proton. In the whole kinematical region of our measurements, the BSA on the bound proton is smaller by 20\% to 40\%, indicating possible medium modification of its partonic structure.
Published: 2018
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45. Search for a Dark Photon in Electro-Produced $e^{+}e^{-}$ Pairs with the Heavy Photon Search Experiment at JLab

Author: Adrian, P. H., Baltzell, N. A., Battaglieri, M., Bondí, M., Boyarinov, S., Bueltmann, S., Burkert, V. D., Calvo, D., Carpinelli, M., Celentano, A., Charles, G., Colaneri, L., Cooper, W., Cuevas, C., D'Angelo, A., Dashyan, N., De Napoli, M., De Vita, R., Deur, A., Dupre, R., Egiyan, H., Elouadrhiri, L., Essig, R., Fadeyev, V., Field, C., Filippi, A., Freyberger, A., Garçon, M., Gevorgyan, N., Girod, F. X., Graf, N., Graham, M., Griffioen, K. A., Grillo, A., Guidal, M., Herbst, R., Holtrop, M., Jaros, J., Kalicy, G., Khandaker, M., Kubarovsky, V., Leonora, E., Livingston, K., Maruyama, T., McCarty, K., McCormick, J., McKinnon, B., Moffeit, K., Moreno, O., Camacho, C. Munoz, Nelson, T., Niccolai, S., Odian, A., Oriunno, M., Osipenko, M., Paremuzyan, R., Paul, S., Randazzo, N., Raydo, B., Reese, B., Rizzo, A., Schuster, P., Sharabian, Y. G., Simi, G., Simonyan, A., Sipala, V., Sokhan, D., Solt, M., Stepanyan, S., Szumila-Vance, H., Toro, N., Uemura, S., Ungaro, M., Voskanyan, H., Weinstein, L. B., Wojtsekhowski, B., and Yale, B.
Subjects: High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract: The Heavy Photon Search experiment took its first data in a 2015 engineering run using a 1.056 GeV, 50 nA electron beam provided by CEBAF at the Thomas Jefferson National Accelerator Facility, searching for an electro-produced dark photon. Using 1.7 days (1170 nb$^{-1}$) of data, a search for a resonance in the $e^{+}e^{-}$ invariant mass distribution between 19 and 81 MeV/c$^2$ showed no evidence of dark photon decays above the large QED background, confirming earlier searches and demonstrating the full functionality of the experiment. Upper limits on the square of the coupling of the dark photon to the Standard Model photon are set at the level of 6$\times$10$^{-6}$. In addition, a search for displaced dark photon decays did not rule out any territory but resulted in a reliable analysis procedure that will probe hitherto unexplored parameter space with future, higher luminosity runs., Comment: 8 pages, Proceedings of the 39th International Conference on High Energy Physics (ICHEP 2018), 4-11 July, 2018, Seoul, Korea
Published: 2018

46. First Measurements of the Double-Polarization Observables $F$, $P$, and $H$ in $\omega$ Photoproduction off Transversely Polarized Protons in the $N^\ast$ Resonance Region

Author: Roy, P., Park, S., Crede, V., Anisovich, A. V., Klempt, E., Nikonov, V. A., Sarantsev, A. V., Wei, N. C., Huang, F., Nakayama, K., Adhikari, K. P., Adhikari, S., Angelini, G., Avakian, H., Barion, L., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Brock, J., Brooks, W. K., Burkert, V. D., Cao, F., Carlin, C., Carman, D. S., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Cole, P. L., Contalbrigo, M., Cortes, O., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Duran, B., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fegan, S., Filippi, A., Fradi, A., Gilfoyle, G. P., Girod, F. X., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hanretty, C., Harrison, N., Hattawy, M., Hayward, T. B., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Joosten, S., Kabir, M. L., Keith, C. D., Keller, D., Khachatryan, G., Khachatryan, M., Khanal, A., Khandaker, M., Kim, A., Kim, W., Klein, F. J., Kubarovsky, V., Kuleshov, S. V., Kunkel, M. C., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., McKinnon, B., Meekins, D. G., Meyer, C. A., Mineeva, T., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Pappalardo, L. L., Paremuzyan, R., Pasyuk, E., Payette, D., Phelps, W., Pierce, J., Pogorelko, O., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schumacher, R. A., Seely, M. L., Sharabian, Y. G., Shrestha, U., Skorodumina, Iu., Sokhan, D., Soto, O., Sparveris, N., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Torayev, B., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Walford, N. K., Wang, R., Watts, D. P., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment, High Energy Physics - Experiment
Abstract: First measurements of double-polarization observables in $\omega$ photoproduction off the proton are presented using transverse target polarization and data from the CEBAF Large Acceptance Spectrometer (CLAS) FROST experiment at Jefferson Lab. The beam-target asymmetry $F$ has been measured using circularly polarized, tagged photons in the energy range 1200 - 2700 MeV, and the beam-target asymmetries $H$ and $P$ have been measured using linearly polarized tagged photons in the energy range 1200 - 2000 MeV. These measurements significantly increase the database on polarization observables. The results are included in two partial-wave analyses and reveal significant contributions from several nucleon ($N^\ast$) resonances. In particular, contributions from new $N^\ast$ resonances listed in the Review of Particle Properties are observed, which aid in reaching the goal of mapping out the nucleon resonance spectrum., Comment: Two authors added, figures updated
Published: 2018
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47. First results on nucleon resonance photocouplings from the $\gamma p \to \pi^+\pi^-p$ reaction

Author: CLAS Collaboration, Golovatch, E., Burkert, V. D., Carman, D. S., Gothe, R. W., Hicks, K., Ishkhanov, B. S., Mokeev, V. I., Pasyuk, E., Adhikari, S., Akbar, Z., Amaryan, M. J., Avakian, H., Ball, J., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Boiarinov, S., Briscoe, W. J., Cao, F., Celentano, A., Chatagnon, P., Chetry, T., Ciullo, G., Clark, L., Clary, B. A., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Elouadrhiri, L., Eugenio, P., Fedotov, G., Fersch, R., Filippi, A., Ghandilyan, Y., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Glazier, D. I., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Joo, K., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Marchand, D., Markov, N., McKinnon, B., Meyer, C. A., Montgomery, R. A., Movsisyan, A., Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strakovsky, I. I., Strauch, S., Taiuti, M., Tan, J. A., Tyler, N., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Wei, X., Wood, M. H., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment
Abstract: We report the first experimental measurements of the nine 1-fold differential cross sections for the $\gamma p \to \pi^+\pi^-p$ reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6~GeV~$
Published: 2018
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48. Beam-Target Helicity Asymmetry $E$ in $K^{0}\Lambda$ and $K^{0}\Sigma^0$ Photoproduction on the Neutron

Author: CLAS Collaboration, Ho, D. H., Schumacher, R. A., D'Angelo, A., Deur, A., Fleming, J., Hanretty, C., Kageya, T., Klein, F. J., Klempt, E., Lowry, M. M., Lu, H., Nikonov, V. A., Peng, P., Sandorfi, A. M., Sarantsev, A. V., Strakovsky, I. I., Walford, N. K., Wei, X., Workman, R. L., Adhikari, K. P., Adhikari, S., Adikaram, D., Akbar, Z., Ball, J., Barion, L., Bashkanov, M., Bass, C. D., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Boiarinov, S., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Chandavar, S., Charles, G., Chatagnon, P., Chetry, T., Ciullo, G., Clary, B. A., Cole, P., Contalbrigo, M., Crede, V., De Vita, R., Defurne, M., Diehl, S., Djalali, C., Dupre, R., Egiyan, H., Ehrhart, M., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Fegan, S., Fersch, R., Filippi, A., Fradi, A., Ghandilyan, Y., Giovanetti, K. L., Girod, F. X., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Hafidi, K., Hakobyan, H., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Isupov, E. L., Jenkins, D., Jo, H. S., Johnston, S., Kabir, M. L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Kubarovsky, V., Laine, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I . J . D., Marchand, D., Markov, N., Mayer, M., McKinnon, B., Meyer, C. A., Mirazita, M., Mokeev, V., Montgomery, R. A., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., O'Connell, T., Osipenko, M., Ostrovidov, A. I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Rehfuss, M., Ripani, M., Riser, D., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Sharabian, Y. G., Skorodumina, Iu., Smith, G. D., Sober, D. I., Sokhan, D., Sparveris, N., Strauch, S., Taiuti, M., Tan, J. A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Watts, D. P., Weinstein, L. B., Whisnant, C. S., Wood, M. H., Zachariou, N., Zhang, J., Zhao, Z. W., and Zonta, I.
Subjects: Nuclear Experiment
Abstract: We report the first measurements of the $E$ beam-target helicity asymmetry for the $\vec{\gamma} \vec{n} \to K^{0}\Lambda$, and $K^{0}\Sigma^{0}$ channels in the energy range 1.70$\leq W\leq$2.34 GeV. The CLAS system at Jefferson Lab uses a circularly polarized photon beam and a target consisting of longitudinally polarized solid molecular hydrogen deuteride with low background contamination for the measurements. The multivariate analysis method boosted decision trees was used to isolate the reactions of interest. Comparisons with predictions from the KaonMAID, SAID, and Bonn-Gatchina models are presented. These results will help separate the isospin $I=0$ and $I=1$ photo-coupling transition amplitudes in pseudoscalar meson photoproduction., Comment: 14 pages, 9 figures; Revised to match published version
Published: 2018
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49. Double $K_S^0$ Photoproduction off the Proton at CLAS

Author: Chandavar, S., Goetz, J. T., Hicks, K., Keller, D., Kunkel, M. C., Paolone, M., Weygand, D. P., Adhikari, K. P., Adhikari, S., Akbar, Z., Ball, J., Balossino, I., Barion, L., Bashkanov, M., Battaglieri, M., Bedlinskiy, I., Biselli, A. S., Briscoe, W. J., Brooks, W. K., Burkert, V. D., Cao, F., Carman, D. S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clark, L., Cole, P. L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., De Sanctis, E., Defurne, M., Deur, A., Djalali, C., Dupre, R., Egiyan, H., Alaoui, A. El, Fassi, L. El, Eugenio, P., Fedotov, G., Filippi, A., Fradi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Girod, F. X., Glazier, D. I., Gohn, W., Golovatch, E., Gothe, R. W., Griffioen, K. A., Guidal, M., Guo, L., Hafidi, K., Hakobyan, H., Hanretty, C., Harrison, N., Hattawy, M., Heddle, D., Holtrop, M., Ilieva, Y., Ireland, D. G., Isupov, E. L., Jenkins, D., Johnston, S., Joo, K., Joosten, S., Kabir, M. L., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Kubarovsky, V., Lanza, L., Lenisa, P., Livingston, K., MacGregor, I. J. D., Markov, N., McCracken, M. E., McKinnon, B., Meyer, C. A., Mineeva, T., Mokeev, V., Movsisyan, A, Camacho, C. Munoz, Nadel-Turonski, P., Niccolai, S., Niculescu, G., Osipenko, M., Ostrovidov, A. I., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J. W., Prok, Y., Protopopescu, D., Raue, B. A., Ripani, M., Riser, D., Ritchie, B. G., Rizzo, A., Rosner, G., Sabatie, F., Salgado, C., Schumacher, R. A., Sharabian, Y. G., Simonyan, A., Skorodumina, Iu., Sokhan, D., Smith, G. D., Sparveris, N., Stepanyan, S., Strakovsky, I. I., Strauch, S., Ungaro, M., Voutier, E., Wei, X., Zachariou, N., Zhang, J., and Zhao, Z. W.
Subjects: Nuclear Experiment
Abstract: The $f_0$(1500) meson resonance is one of several contenders to have significant mixing with the lightest glueball. This resonance is well established from several previous experiments. Here we present the first photoproduction data for the $f_0$(1500) via decay into the $K_S^0 K_S^0$ channel using the CLAS detector. The reaction $\gamma p$ -> $f_0 p$ -> $K_S^0 K_S^0 p$, where J = 0, 2, was measured with photon energies from 2.7 to 5.1 GeV. A clear peak is seen at 1500 MeV in the background subtracted invariant mass spectra of the two kaons. This is enhanced if the measured 4-momentum transfer to the proton target is restricted to be less than 1.0 GeV2. By comparing data with simulations, it can be concluded that the peak at 1500 MeV is produced primarily at low t, which is consistent with a t-channel production mechanism., Comment: 12 pages, 12 figures
Published: 2017
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50. Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab: an update on PR12-16-001

Author: Battaglieri, M., Bersani, A., Bracco, G., Caiffi, B., Celentano, A., De Vita, R., Marsicano, L., Musico, P., Osipenko, M., Panza, F., Ripani, M., Santopinto, E., Taiuti, M., Bellini, V., Bondi', M., Castorina, P., De Napoli, M., Italiano, A., Kuznetzov, V., Leonora, E., Mammoliti, F., Randazzo, N., Re, L., Russo, G., Russo, M., Shahinyan, A., Sperduto, M., Spinali, S., Sutera, C., Tortorici, F., Baltzell, N., Dalton, M., Freyberger, A., Girod, F. -X., Kharashvili, G., Kubarovsky, V., Pasyuk, E., Smith, E. S., Stepanyan, S., Ungaro, M., Whitlatch, T., Izaguirre, E., Krnjaic, G., Snowden-Ifft, D., Loomba, D., Carpinelli, M., D'Urso, D., Gabrieli, A., Maccioni, G., Sant, M., Sipala, V., Ameli, F., Cisbani, E., De Persio, F., Del Dotto, A., Garibaldi, F., Meddi, F., Nicolau, C. A., Urciuoli, G. M., Chiarusi, T., Manzali, M., Pellegrino, C., Schuster, P., Toro, N., Essig, R., Wood, M. H., Paremuzyan, M. Holtrop. R., De Cataldo, G., De Leo, R., Di Bari, D., Lagamba, L., Nappi, E., Perrino, R., Balossino, I., Barion, L., Ciullo, G., Contalbrigo, M., Drago, A., Lenisa, P., Movsisyan, A., Pappalardo, L., Spizzo, F., Turisini, M., Hasch, D., Lucherini, V., Mirazita, M., Pisano, S., Rossi, P., Tomassini, S., Simi, G., D'Angelo, A., Lanza, L., Rizzo, A., Schaerf, C., Zonta, I., Filippi, A., Genovese, M., Fegan, S., Kunkel, M., Bashkanov, M., Murphy, A., Smith, G., Watts, D., Zachariou, N., Zana, L., Glazier, D., Ireland, D., McKinnon, B., Sokhan, D., Colaneri, L., Pereira, S. Anefalos, Afanasev, A., Briscoe, B., Strakovsky, I., Kalantarians, N., Weinstein, L., Adhikari, K. P., Dunne, J. A., Dutta, D., Fassi, L. El, Ye, L., Hicks, K., Cole, P., Dobbs, S., Fanelli, C., and Murthy, P. T. M.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: This document is an update to the proposal PR12-16-001 Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab submitted to JLab-PAC44 in 2016 reporting progress in addressing questions raised regarding the beam-on backgrounds. The concerns are addressed by adopting a new simulation tool, FLUKA, and planning measurements of muon fluxes from the dump with its existing shielding around the dump. First, we have implemented the detailed BDX experimental geometry into a FLUKA simulation, in consultation with experts from the JLab Radiation Control Group. The FLUKA simulation has been compared directly to our GEANT4 simulations and shown to agree in regions of validity. The FLUKA interaction package, with a tuned set of biasing weights, is naturally able to generate reliable particle distributions with very small probabilities and therefore predict rates at the detector location beyond the planned shielding around the beam dump. Second, we have developed a plan to conduct measurements of the muon ux from the Hall-A dump in its current configuration to validate our simulations., Comment: Document submitted to JLab PAC 45
Published: 2017

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