The Fragmentation Spectrum from Space-Time Reciprocity

TL;DR

This paper investigates the hadronization process in electron-positron collisions by resumming soft terms in the jet production spectrum, supporting local parton-hadron duality with strong data agreement.

Contribution

It introduces a systematic resummation method based on space-time reciprocity to model the hadronization spectrum, extending previous approaches.

Findings

Excellent agreement with experimental data

Resummed jet function effectively models non-perturbative fragmentation

Supports local parton-hadron duality hypothesis

Abstract

Analyzing the single inclusive annihilation spectrum of charged hadrons in $e^+e^-$ collisions, I confront the hadronization hypothesis of local parton-hadron duality with a systematic resummation of the dependence on the small energy fraction. This resummation is based on the reciprocity between time-like and space-like splitting processes in $4-2\epsilon$-dimensions, which I extend to resum all the soft terms of the cross-section for inclusive jet production. Under the local-parton-hadron duality hypothesis, the resulting distribution of jets essentially determines the spectrum of hadrons as the jet radius goes to zero. Thus I take the resummed perturbative jet function as the non-perturbative fragmentation function with an effective infra-red coupling. I find excellent agreement with data, and comment on the mixed leading log approximation previously used to justify local parton-hadron duality.