Nuclear and Particle Physics Colloquium 99

(核与粒子物理学术报告会99)

Place: Tencent Meeting (ID 416 267 274)

Time: 15:00-17:00, March 10th, 2020

Title: GPDs and Sivers distribution functions of sea quark in proton

Speaker: Fangcheng He

Abstract:

We calculate the unpolarized generalized parton distributions (GPDs) and Sivers function of sea quark in proton using nonlocal chiral Lagrangian. In the calculation of GPDs, the regulator is generated from the nonlocal interaction where the gauge link is introduced to guarantee local $U(1)_V$ gauge invariant. As a result, additional diagrams from the expansion of the gauge link ensure the conservation of electric and strange charges of proton. Sea quark flavour asymmetry at finite momentum transfer as well as the strange form factors are obtained from the calculated GPDs. The results are comparable with the phonological extraction and Lattice results. In the calculation of Sivers distribution functions, By introducing the gauge link of the vector meson, the transverse momentum dependent distribution of a pion in the nucleon is re-defined which is locally $SU(2)_V$ invariant. By combining the calculated splitting function and the valence $\bar{q}$ distribution in pion from the recent fit, the sea quark Sivers function in proton is obtained. We find reasonable numerical results for the first momentum of Sivers distribution functions.

About speaker:

He graduated from Yunnan University in 2015. From 2015 to present, he has been studying theoretical physics at Institute of High Energy Physics, UACS as a Ph.D. candidate under the supervision of Prof. Ping Wang.