English

Single spin asymmetry $A_{UL}^{\sin(2\phi_h-2\phi_R)}$ in dihadron semi-inclusive DIS

High Energy Physics - Phenomenology 2020-08-05 v1

Abstract

The single longitudinal spin asymmetry AULsin(2ϕh2ϕR)A_{UL}^{\sin(2\phi_h-2\phi_R)} of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) is examined through helicity-dependent dihadron fragmentation function (DiFF) G1G_1^\perp. The correlation of the longitudinal polarization of a fragmenting quark with the transverse momenta of the produced hadron pair is illustrated by this DiFF. The experimental investigation for this azimuthal asymmetry in dihadron SIDIS by the COMPASS Collaboration has lately yielded a very small signal. Here, the unknown T-odd dihadron fragmentation function G1G_1^\perp utilizing a spectator model is computed. The model has been successfully used to describe the dihadron production in both the unpolarized and the single polarized processes to access the asymmetry and clarify why the signal is very small. The transverse momentum dependent factorization method, in which the transverse momentum of the final state hadron pair is left unintegrated, has been considered. The sin(2ϕh2ϕR)\sin(2\phi_h-2\phi_R) asymmetry at the COMPASS kinematics is estimated and we compare it with the data. Besides, the predictions on the same asymmetry are also made at the HERMES and Electron Ion Collider.

Keywords

Cite

@article{arxiv.2004.13507,
  title  = {Single spin asymmetry $A_{UL}^{\sin(2\phi_h-2\phi_R)}$ in dihadron semi-inclusive DIS},
  author = {Xuan Luo and Hao Sun},
  journal= {arXiv preprint arXiv:2004.13507},
  year   = {2020}
}

Comments

5 figures. arXiv admin note: text overlap with arXiv:1906.05674