A multidimensional study of the structure function ratio $\sigma_{LT'}$/$\sigma_0$ from hard exclusive $\pi^+$ electro-production off protons in the GPD regime

• Published in: Physics letters. B Vol. 839
• Main Authors: Joo, K., Achenbach, P., Baashen, L., Barion, L., Battaglieri, M., Bedlinskiy, I., Benkel, B., Benmokhtar, F., Bossù, F., Boiarinov, S., Briscoe, W. J., Bulumulla, D., Burkert, V. D., Carman, D. S., Celentano, A., Chesnokov, V., Clash, G., Cole, P. L., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Djalali, C., Dupre, R., Ehrhart, M., El Alaoui, A., El Fassi, L., Filippi, A., Gavalian, G., Ghandilyan, Y., Gilfoyle, G. P., Glazier, D. I., Golubenko, A. A., Gosta, G., Gothe, R. W., Gotra, Y., Guidal, M., Hafidi, K., Hattawy, M., Hayward, T. B., Holtrop, M., Ilieva, Y., Isupov, E. L., Jo, H. S., Kim, W., Kripko, A., Kubarovsky, V., Lagerquist, V., Laget, J. -M., Leali, M., Lee, S., Lenisa, P., Livingston, K., .J .D. MacGregor, I., Mascagna, V., Meziani, Z. E., Migliorati, S., Mineeva, T., Mirazita, M., Mokeev, V., Molina, E., Nadel-Turonski, P., Naidoo, P., Nicol, M., Osipenko, M., Pandey, P., Paremuzyan, R., Pasyuk, E., Paul, S. J., Pilleux, N., Pokhrel, M., Poudel, J., Price, J. W., Reed, T., Richards, J., Ripani, M., Ritman, J., Sabatié, F., Salgado, C., Sharabian, Y., Shirokov, E. V., Shrestha, U., Simmerling, P., Sokhan, D., Spreafico, M., Stepanyan, S., Strakovsky, I. I., Strauch, S., Tan, J. A., Trotta, N., Turisini, M., Ungaro, M., Vallarino, S., Venturelli, L., Voskanyan, H., Voutier, E., Watts, D. P., Wei, X., Williams, R., Zachariou, N.
• Format: Journal Article
• Language: English
• Published: United States Elsevier 09-02-2023
• Subjects: CLAS12; eletroproduction; exclusive single pion; GPD; PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
• ISSN: 0370-2693; 1873-2445

A multidimensional extraction of the structure function ratio σLT'/σ0 from the hard exclusive $\vec{e}$p → e'nπ+ 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/Q2 $\ll$ 1) with a wide kinematic range of xB in the valence regime (0.17 < xB < 0.55), and virtualities Q2 ranging from 1.5 GeV2 up to 6 GeV2. 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 Q2, while the GPD model is more appropriate at high Q2.