Deep Exclusive Electroproduction of ${\ensuremath{\pi}}^{0}$ at High ${Q}^{2}$ in the Quark Valence Regime

Open Access

Deep Exclusive Electroproduction of $π^{0}$ at High $Q^{2}$ in the Quark Valence Regime

M. Dlamini et al. (Jefferson Lab Hall A Collaboration)

Phys. Rev. Lett. 127, 152301 – Published 5 October 2021

Abstract

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of $x_{B}$ (0.36, 0.48, and 0.60) and $Q^{2}$ (3.1 to $8.4 {GeV}^{2}$ ) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions $d σ_{T} / d t + ε d σ_{L} / d t$ , $d σ_{T T} / d t$ , $d σ_{L T} / d t$ , and $d σ_{L T^{'}} / d t$ are extracted as a function of the proton momentum transfer $t - t_{\min}$ . The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

Received 2 December 2020
Revised 7 June 2021
Accepted 17 August 2021

DOI:https://doi.org/10.1103/PhysRevLett.127.152301

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

Published by the American Physical Society