Spin 1 Transverse Momentum Dependent Tensor Structure Functions in CLAS12

TL;DR

This paper proposes analyzing CLAS12 data to extract tensor polarized structure functions in deuteron, pioneering the first SIDIS analysis of tensor polarized TMDs to explore spin-1 nuclear structure.

Contribution

It introduces the first SIDIS analysis to extract tensor polarized structure functions and TMDs in spin-1 nuclei, expanding understanding of nuclear spin structure.

Findings

First extraction of tensor structure functions from SIDIS data.

Identification of tensor-polarized TMDs $f_{1LL}$ and $h^{ot}_{1LL}$.

Initial measurements enabling future detailed studies.

Abstract

We propose to analyze CLAS12 RG-C data to study the tensor transverse-momentum-dependent parton distribution functions (TMDs) on deuteron data. The deuteron is the lightest nucleus with spin-1, in essence a weakly bound system of two spin-1/2 nucleons. However, one of the most intriguing characteristics of the deuteron is that the tensor polarized structure provides direct access to the quark and gluon distribution of light nuclear system, which cannot be naively constructed from the proton and neutron. We will study the tensor polarized structure functions with the Semi-inclusive Deep Inelastic Scattering (SIDIS) $eD \arrow eP_{h}X$ and Inclusive processes in the available data on deuterated ammonia (ND3) target. We will perform the first ever SIDIS analysis extraction of the tensor structure functions, which can be interpreted in term of completely unexplored tensor polarized TMDs. Our analysis will focus on the extraction of the tensor structure functions b1 from inclusive process, and $F_{U(LL),T}$ and $F^{cos 2\phi_{h}}_{U(LL)}$ from SIDIS. These last two structure functions carry information related to two tensor-polarized TMDs, $f_{1LL}$ and $h^{\perp}_{1LL}$. These initial exploratory measurements of tensor-polarized structure functions will enable the first extraction of spin-1 TMDs and motivate more precise future measurements.