학술논문
Observation of Beam Spin Asymmetries in the Process $e p \rightarrow e \pi^{+}\pi^{-}X$ with CLAS12
Document Type
Working Paper
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.; Zhang, J.
Source
Phys. Rev. Lett. 126, 152501 (2021)
Subject
Language
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
Comment: 6 pages, 5 figures