A multidimensional study of the structure function ratio From Hard Exclusive electro-production off protons in the GPD regime
S. Diehl (University of Connecticut, Storrs, USA, II Physikalisches Institut der Universitaet Giessen, Giessen, Germany)
; A. Kim (University of Connecticut, Storrs, USA); K. Joo (University of Connecticut, Storrs, USA); P. Achenbach (Thomas Jefferson National Accelerator Facility, Newport News, USA); Z. Akbar (Florida State University, Tallahassee, USA, University of Virginia, Charlottesville, USA); et al - Show all 154 authors
A multidimensional extraction of the structure function ratio from the hard exclusive 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 ( ≪ 1) with a wide kinematic range of in the valence regime (0.17 < < 0.55), and virtualities 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 , while the GPD model is more appropriate at high .
