Role of sea quarks in the nucleon transverse spin

We present a phenomenological extraction of transversity distribution functions and Collins fragmentation functions by simultaneously fitting to semi-inclusive deep inelastic scattering and electron-positron annihilation data. The analysis is performed within the transverse-momentum-dependent factorization formalism, and sea quark transversity distributions are taken into account for the first time. We find the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mover accent="true"><a:mi>u</a:mi><a:mo stretchy="false">¯</a:mo></a:mover></a:math> quark favors a negative transversity distribution, while that of the <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mover accent="true"><e:mi>d</e:mi><e:mo stretchy="false">¯</e:mo></e:mover></e:math> quark is consistent with zero according to the current accuracy. In addition, based on a combined analysis of world data and simulated data, we quantitatively demonstrate the impact of the proposed Electron-Ion Collider in China on precise determinations of the transversity distributions, especially for sea quarks, and the Collins fragmentation functions. Published by the American Physical Society 2024