Single Transverse Spin Asymmetries in Semi-inclusive Deep Inelastic Scattering in a Spin-1 Diquark Model

TL;DR

This paper models single transverse spin asymmetries in semi-inclusive deep inelastic scattering using a spin-1 diquark model, highlighting the role of final-state interactions and complex phases in generating observable asymmetries.

Contribution

It introduces a light front wave function model with a spin-1 diquark to estimate SSAs and analyze the effects of final-state interactions on distribution functions.

Findings

Final-state interactions produce phases leading to SSAs.

The model estimates Sivers and Boer-Mulders functions.

Different coupling constants affect the asymmetries.

Abstract

The observed results for the azimuthal single spin asymmetries (SSAs) of the proton, measured in the semi-inclusive deep inelastic scattering (SIDIS), can be explained by the final-state interaction (FSI) from the gluon exchange between the outgoing quark and the target spectator system. SSAs require a phase difference between two amplitudes coupling the target with opposite spins to the same final state. We have used the model of light front wave functions (LFWFs) consisting of a spin-$\frac{1}{2}$ system as a composite of a spin-$\frac{1}{2}$ fermion and a spin-1 vector boson to estimate the SSAs. The implications of such a model have been investigated in detail by considering different coupling constants. The FSIs also produce a complex phase which can be included in the LFWFs to calculate the Sivers and Boer-Mulders distribution functions of the nucleon.