Deep exclusive ${\pi }^{+}$ electroproduction off the proton at CLAS

Abstract

The exclusive electroproduction of ${\pi }^{+}$ above the resonance region was studied using the $\mathrm{CEBAF}$ Large Acceptance Spectrometer ($\mathrm{CLAS}$) at Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of $\mathrm{CLAS}$, together with the high luminosity, allowed us to measure the cross section for the ${\gamma }^{\ast }p\to n{\pi }^{+}$ process in 140 ($Q^2$, $x_B$, $t$) bins: $0.16<x_B<0.58$, 1.6 GeV${}^2<$$Q^2$$<4.5$ GeV${}^2$ and 0.1 GeV${}^2<$$-t$$<5.3$ GeV${}^2$. For most bins, the statistical accuracy is on the order of a few percent. Differential cross sections are compared to two theoretical models, based either on hadronic (Regge phenomenology) or on partonic (handbag diagram) degrees of freedom. Both can describe the gross features of the data reasonably well, but differ strongly in their ingredients. If the handbag approach can be validated in this kinematical region, our data contain the interesting potential to experimentally access transversity Generalized Parton Distributions.

18pages, 21figures,2tables

References in corpus (6)

• Charged pion form factor between $Q^2$=0.60 and 2.45 GeV${}^2$. I. Measurements of the cross section for the ${}^1$H($e,e^{\prime }{\pi }^{+}$)$n$ reaction
• Scaling study of the pion electroproduction cross sections and the pion form factor
• Cross sections for hard exclusive electroproduction of pi+ mesons on a hydrogen target
• Deeply inelastic pions in the exclusive reaction $p(e,e^{\prime }{\pi }^{+})n$ above the resonance region
• Scaling and Resonances in Elementary K^+ Lambda Photoproduction
• Deep exclusive electroproduction of ${\pi }^{+}$ at HERMES