t3evol - Numerical Solution of Twist-three Evolution Equations

TL;DR

The paper introduces t3evol, a numerical program for solving twist-three evolution equations relevant to spin asymmetries and polarized structure functions, accommodating various flavor sectors and initial conditions.

Contribution

It provides a new computational tool for the numerical solution of twist-three evolution equations, enabling detailed studies of spin-dependent phenomena.

Findings

Successfully solves flavor nonsinglet and singlet evolution equations

Supports arbitrary initial distributions for flexible modeling

Applicable to physical observables like single spin asymmetries

Abstract

A program dedicated to the numerical solution of the evolution equations for twist-three multiparton correlation functions is presented. The solutions are obtained by direct integration on a discretized momentum fraction grid. Both flavor nonsinglet and flavor singlet evolution (in both $C$-parity sectors) can be addressed. Physical applications include single spin asymmetries and the subleading twist contribution to the polarized structure function $g_2$. An arbitrary input is accepted for the initial distributions.