Simplified approach to extracting nucleon transversity in collinear factorization using near-side energy-energy correlators

TL;DR

This paper introduces a new collinear factorization method using near-side energy-energy correlators to access the nucleon's transversity PDF, simplifying previous approaches and enabling experimental extraction.

Contribution

It presents a novel analytical framework for measuring transversity PDFs via energy-energy correlators, avoiding complex modeling of intrinsic transverse momentum and resonances.

Findings

Derived leading-order analytical expressions for spin observables.

Showed the similarity of these expressions to standard PDF and fragmentation function formulas.

Predicted feasible experimental kinematics for future measurements.

Abstract

We develop a novel strategy for accessing the transversity parton distribution function (PDF) of the nucleon within collinear factorization using near-side energy-energy correlators in the dihadron fragmentation framework. We show how this removes the complications of previous approaches that must model either intrinsic parton transverse momentum or resonances in the invariant mass distribution of a final-state dihadron. We present leading-order analytical results for transverse-spin observables in semi-inclusive deep-inelastic scattering and electron-positron annihilation, highlighting their close similarity to the expressions one uses in extracting (un)polarized PDFs and (single-hadron) fragmentation functions in collinear factorization. We make predictions for kinematics relevant for existing and future facilities that demonstrate the feasibility of an energy-energy correlator program in extracting the transversity PDF.