Exclusive η electroproduction at W>2 GeV with CLAS and transversity generalized parton distributions

Le résumé fourni par la source

The cross section of the exclusive $\ensuremath{\eta}$ electroproduction reaction $ep\ensuremath{\rightarrow}{e}^{\ensuremath{'}}{p}^{\ensuremath{'}}\ensuremath{\eta}$ was measured at Jefferson Laboratory with a 5.75 GeV electron beam and the CLAS detector. Differential cross sections ${d}^{4}\ensuremath{\sigma}/dtd{Q}^{2}d{x}_{B}d{\ensuremath{\phi}}_{\ensuremath{\eta}}$ and structure functions ${\ensuremath{\sigma}}_{U}={\ensuremath{\sigma}}_{T}+\ensuremath{\epsilon}{\ensuremath{\sigma}}_{L},\phantom{\rule{4pt}{0ex}}{\ensuremath{\sigma}}_{TT}$, and ${\ensuremath{\sigma}}_{LT}$, as functions of $t$, were obtained over a wide range of ${Q}^{2}$ and ${x}_{B}$. The $\ensuremath{\eta}$ structure functions are compared with those previously measured for ${\ensuremath{\pi}}^{0}$ at the same kinematics. At low $t$, both ${\ensuremath{\pi}}^{0}$ and $\ensuremath{\eta}$ are described reasonably well by generalized parton distributions (GPDs) in which chiral-odd transversity GPDs are dominant. The ${\ensuremath{\pi}}^{0}$ and $\ensuremath{\eta}$ data, when taken together, can facilitate the flavor decomposition of the transversity GPDs.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.