Sivers and cos2ϕ asymmetries in semi-inclusive deep inelastic scattering in light-front holographic model

Tanmay Maji,Asmita Mukherjee,Dipankar Chakrabarti

doi:10.1103/physrevd.97.014016

Abstract

The spin asymmetries in SIDIS associated with $T$-odd TMDs are presented in a light-front quark-diquark model of a proton. To incorporate the effects of the final-state interaction, the light front wave functions are modified to have a phase factor which is essential to have Sivers or Boer-Mulders functions. The Sivers and Boer-Mulder asymmetries are compared with HERMES and COMPASS data.

Highlights

Transverse momentum dependent parton distributions (TMDs) [1,2] are important to understand the single spin asymmetries observed experimentally for a long time [3,4]
The motivation of the present work is to calculate the Sivers and Boer-Mulders function using a recently developed quark-diquark model light-front wave function of the proton based on light-front holography, calculate the asymmetries to compare with the data and investigate to what extent the model-dependent relations hold
We have presented the results for T-odd TMDs, namely, the Sivers and Boer-Mulders functions, in a light-front quark-diquark model of the proton and the spin asymmetries in semiinclusive deep inelastic scattering (SIDIS) associated with these functions

Summary

INTRODUCTION

Transverse momentum dependent parton distributions (TMDs) [1,2] are important to understand the single spin asymmetries observed experimentally for a long time [3,4]. The average transverse momentum of an unpolarized quark in a transversely polarized nucleon generated due to the Sivers effect is related to the distortion in impact parameter space through a lensing function, which is the effect of final-state interaction This relation is found to hold in spectator-type models to the lowest nontrivial order, expected to break down when higher order effects are taken into account. The motivation of the present work is to calculate the Sivers and Boer-Mulders function using a recently developed quark-diquark model light-front wave function of the proton based on light-front holography, calculate the asymmetries to compare with the data and investigate to what extent the model-dependent relations hold. The spin asymmetries evaluated in this model are compared with the experimental data using the QCD evolution prescribed by Abyat and Rogers [42]

LIGHT-FRONT QUARK-DIQUARK MODEL FOR NUCLEON

SIVERS ASYMMETRY AND BOER-MULDERS ASYMMETRY

SPIN DENSITIES

CONCLUSIONS