SUSY-like relation of the splitting functions in evolution of gluon and quark jet multiplicities

TL;DR

This paper uncovers a SUSY-like relation between the anomalous dimensions in the DGLAP evolution of quark and gluon jet multiplicities, using high-order resummation and data fitting to determine the strong coupling constant.

Contribution

It introduces a new SUSY-like relation in the evolution equations for jet multiplicities, extending known relationships beyond supersymmetric QCD.

Findings

Derived a new relation between anomalous dimensions in jet evolution.

Fitted world data to extract alpha_s(MZ)=0.1205 with uncertainties.

Utilized high-order resummation up to NNNLO for analysis.

Abstract

We show the new relationship [1] between the anomalous dimensions, resummed through next-to-next-to-leading-logarithmic order, in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for the first Mellin moments D_{q,g}(mu2) of the quark and gluon fragmentation functions, which correspond to the average hadron multiplicities in jets initiated by quarks and gluons, respectively. So far, such relationships have only been known from supersymmetric (SUSY) QCD. Exploiting available next-to-next-to-next-to-leading-order (NNNLO) information on the ratio D_g^+(mu2)/D_q^+(mu2) of the dominant plus components, the fit of the world data of D_{q,g}(mu2) for charged hadrons measured in e+e- annihilation leads to alpha_s^{(5)}(MZ)=0.1205 + 0.0016 - 0.0020.