Higher twist effects in $e^+e^-$ annihilation at high energies

TL;DR

This paper develops a formalism using collinear expansion to systematically analyze both leading and higher twist contributions to hadron production in electron-positron annihilation, covering various hadron spins.

Contribution

It introduces a systematic approach to study higher twist effects in $e^+ e^-$ annihilation using collinear expansion, applicable to different hadron spins.

Findings

Derived a formalism for higher twist contributions to fragmentation functions.

Applied the formalism to hadrons with various spins.

Provided a systematic method for analyzing twist effects at tree level.

Abstract

In the two papers published recently, we apply collinear expansion to both inclusive ($e^+ e^- \to h+X$) and semi-inclusive ($e^+ e^- \to h + \bar q + X$) hadron production in $e^+ e^-$ annihilation to derive a formalism suitable for a systematic study of leading as well as higher twist contributions to fragmentation functions at the tree level. We carry out the calculations for hadrons with spin-0, spin-1/2 as well as spin-1. This proceeding is mainly a summary of these two papers.