Unpolarized and beam-polarized fourfold cross sections (d^4σ/dQ^2dx_Bdtdϕ) for the ep→e^'p^'γ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 (Q^2,x_B,t) bins over the widest phase space ever explored in the valence-quark region. Several models of generalized parton distributions (GPDs) describe the data well at most of our kinematics. This increases our confidence that we understand the GPD H, expected to be the dominant contributor to these observables. Through a leading-twist extraction of Compton form factors, these results support the model predictions of a larger nucleon size at lower quark-momentum fraction x_B.
Jo, H., Girod, F., Avakian, H., Burkert, V., Garcon, M., Guidal, M., et al. (2015). Cross Sections for the Exclusive Photon Electroproduction on the Proton and Generalized Parton Distributions. PHYSICAL REVIEW LETTERS, 115(21), 212003 [10.1103/PhysRevLett.115.212003].
Cross Sections for the Exclusive Photon Electroproduction on the Proton and Generalized Parton Distributions
COLANERI, LUCA;D'ANGELO, ANNALISA;PISANO, SILVIA;RIZZO, ALESSANDRO;ZONTA, IRENE
2015-11-17
Abstract
Unpolarized and beam-polarized fourfold cross sections (d^4σ/dQ^2dx_Bdtdϕ) for the ep→e^'p^'γ reaction were measured using the CLAS detector and the 5.75-GeV polarized electron beam of the Jefferson Lab accelerator, for 110 (Q^2,x_B,t) bins over the widest phase space ever explored in the valence-quark region. Several models of generalized parton distributions (GPDs) describe the data well at most of our kinematics. This increases our confidence that we understand the GPD H, expected to be the dominant contributor to these observables. Through a leading-twist extraction of Compton form factors, these results support the model predictions of a larger nucleon size at lower quark-momentum fraction x_B.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
