A multidimensional study of the structure function ratio σLT′/σ0 from hard exclusive π+ electro-production off protons in the GPD regime
CLAS12, Eletroproduction, Exclusive single pion, GPD
A multidimensional extraction of the structure function ratio σLT′/σ0 from the hard exclusive 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 ≪ 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.
Diehl, S.; Kim, A.; Joo, K.; Achenbach, P.; Akbar, Z.; Amaryan, M. J.; Atac, H.; Avagyan, H.; Ayerbe Gayoso, C.; Baashen, L.; 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.; Carman, D. S.; Celentano, A.; and Djalali, C., "A multidimensional study of the structure function ratio σLT′/σ0 from hard exclusive π+ electro-production off protons in the GPD regime" (2023). Physics & Astronomy Open Access Publications. 170.