Sin(phi) azimuthal asymmetry in semi-inclusive electroproduction on longitudinally polarized nucleon

TL;DR

This work analyzes the $1/Q$-suppressed sinφ azimuthal asymmetry in semi-inclusive deep-inelastic scattering with a longitudinally polarized target. It derives the polarized SIDIS cross section at leading and subleading twists, isolating contributions from twist-two and twist-three distribution and fragmentation functions, including naively T-odd fragmentation via the Collins mechanism. Using a Gaussian TMD Ansatz and the JMR diquark spectator model (with two input sets), the authors estimate the weighted asymmetry and the unweighted sinφ moments at HERMES kinematics, finding percent-level effects with notable I2L and I2T contributions. The results suggest that measurements of this asymmetry can provide access to T-odd fragmentation functions such as H1^⊥ and tilde H, advancing our understanding of spin-dependent hadronization in SIDIS.

Abstract

We investigate the $sin φ$ azimuthal asymmetry in the semi-inclusive deep-inelastic lepton scattering off longitudinally polarized nucleon target arising from the time reversal odd structures. The order 1/Q contributions of the leading twist and twist-three distribution and fragmentation functions to that asymmetry for the certain kinematical conditions are numerically estimated.