Extraction of transhelicity worm-gear distributions and opportunities at the Electron-Ion Collider in China

Abstract

We present a global analysis of the transhelicity worm-gear distribution function, g1T⊥, by fitting the longitudinal-transverse double-spin asymmetry data of the semi-inclusive deep inelastic scattering. The analysis is performed within the framework of transverse momentum dependent factorization and evolution. It is found that the u-quark favors a positive distribution and the d-quark favors a negative distribution, which is consistent with previous model calculations and phenomenological extractions. Based on the fit to existing world data, we also study the impact of the proposed Electron-Ion Collider in China and conclude that it can significantly improve the precision of the worm-gear distribution function and hence enhance our understanding of nucleon spin structures. Published by the American Physical Society 2024