Single spin asymmetry in transverse polarized proton production and production in semi-inclusive DIS at twist-3

Yongliang Yang; Wenjuan Mao; Zhun Lu

doi:10.1140/epjp/i2019-12624-0

EPJ

a
b
c
d
e
ap
st
h
plus
ds
pv
ti
qt
am
n

2024 Impact factor 2.9

EPJ PLUS - Condensed Matter and Complex Systems

Eur. Phys. J. Plus (2019) 134: 259
https://doi.org/10.1140/epjp/i2019-12624-0

Regular Article

Single spin asymmetry in transverse polarized proton production and $\Lambda$ production in semi-inclusive DIS at twist-3

Yongliang Yang¹, Wenjuan Mao² and Zhun Lu¹^*

¹ School of Physics, Southeast University, 211189, Nanjing, China
² School of Physics and Telecommunication Engineering, Zhoukou Normal University, 466000, Zhoukou, Henan, China

^* e-mail: zhunlu@seu.edu.cln

Received: 1 September 2018
Accepted: 11 March 2019
Published online: 11 June 2019

Abstract

We study the single spin asymmetry in the transversely polarized proton production and the $\Lambda$ hyperon production in semi-inclusive deep inelastic scattering with a $\sin \phi_{S_h}$ modulation, in which $\phi_{S_h}$ is the azimuthal angle of the transverse spin of the final hadron. The theoretical interpretation for the asymmetry is presented as the convolution of the twist-3 quark transverse-momentum-dependent distributions and twist-2 fragmentation functions. We investigate the role of the twist-3 distribution functions $h(x,\mathbf{p}_{T}^{2})$ , $f^{\perp}(x,\mathbf{p}_{T}^{2})$ and $g^{\perp}(x,\mathbf{p}_{T}^{2})$ and the twist-2 fragmentation functions $H_{1}(x,\mathbf{k}_{T}^{2})$ , $D_{1T}^\perp(x,\mathbf{k}_T^2)$ and $G_{1T}(x,\mathbf{k}_T^2)$ in this asymmetry. Using the spectator models, we compute these distribution functions and fragmentation functions and estimate their contribution to the $\sin \phi_{S_{h}}$ asymmetry for the proton production as well as for the $\Lambda$ production at JLab with a 12GeV electron beam. The asymmetry at the COMPASS kinematics is also predicted. By comparing different sources for the asymmetry, we conclude that sizable $\sin \phi_{S_{h}}$ asymmetry for the transversely polarized proton production might be accessible in the SIDIS at the kinematics of JLab and COMPASS.