English

The $\sin(2\phi)$ azimuthal asymmetry in exclusive $\pi^0$ production

High Energy Physics - Phenomenology 2025-08-22 v1

Abstract

The sin(2ϕ)\sin(2\phi) azimuthal angular correlation between the transverse momenta of the scattered electron and the recoil proton in the epepπ0ep\to e^\prime p^\prime \pi^0 process provides a probe for quark orbital angular momentum. We numerically calculate this asymmetry for the future Electron-Ion Collider (EIC) in the U.S. and China (EicC) kinematics using a light-front quark-scalar-diquark model, in which the light-front wave functions (LFWFs) are derived from the soft-wall AdS/QCD framework. We also investigate the properties of the valence quark angular momentum expressed in terms of helicity-independent and helicity-dependent parton distributions. This study aims to establish theoretical constraints on the asymmetry sensitive to the quark orbital angular momentum prior to its first experimental measurement.

Keywords

Cite

@article{arxiv.2508.15181,
  title  = {The $\sin(2\phi)$ azimuthal asymmetry in exclusive $\pi^0$ production},
  author = {Chentao Tan and Zhun Lu},
  journal= {arXiv preprint arXiv:2508.15181},
  year   = {2025}
}

Comments

16 pages, 4 figures