Extraction of the higher-twist parton distribution $e(x)$ from CLAS data

TL;DR

This paper reports the first point-by-point extraction of the twist-3 parton distribution $e(x)$ from recent CLAS data, providing new insights into quark-gluon correlations and the scalar charge of the nucleon.

Contribution

It introduces a novel analysis of CLAS data to extract the scalar PDF $e(x)$ at the twist-3 level using dihadron semi-inclusive DIS data.

Findings

The scalar PDF $e(x)$ is non-zero with over 74% probability.

First point-by-point extraction of a twist-3 PDF from experimental data.

Insights into quark-gluon correlations and nucleon scalar charge.

Abstract

This manuscript presents the new analysis of recent CLAS and CLAS12 data aimed at the extraction of $e(x)$. This publication benefits from a proof-of-principle analysis of a smaller preliminary data set published in a preprint form in \url{1405.7659}. We present the first point-by-point extraction of a twist-3 PDF. The scalar PDF, $e(x)$, is accessed through the analysis of the data for the $\sin\phi_R$-moment of the beam-spin asymmetry for dihadron production in semi-inclusive DIS off proton target at CLAS and CLAS12. The dihadron formalism allows for use of collinear framework, hence calling for a minimal set of approximations and hypotheses. The extracted PDF $e(x)$ carries insights into the physics of the largely-unexplored quark-gluon correlations, and its first Mellin moment is related to the marginally-known scalar charge of the nucleon. We show that the proton flavor combination of the scalar PDF is non-zero at more than $74\%$ probability.