A multidimensional study of the structure function ratio σLT′/σ0 from hard exclusive π+ electro-production off protons in the GPD regime
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
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., 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., & Bondi, M. (2023). A multidimensional study of the structure function ratio σLT′/σ0 from hard exclusive π+ electro-production off protons in the GPD regime. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 839. https://doi.org/10.1016/j.physletb.2023.137761