Study on the Energy Dependence of the Radii of Jets by the HBT Correlation Method in e+e- collisions

TL;DR

This study investigates how the sizes of quark and gluon jets, measured via HBT correlations in e+e- collisions, remain constant across different energies using Monte Carlo simulations.

Contribution

It provides the first detailed analysis of jet radii energy dependence using HBT correlations in e+e- collisions with extensive Monte Carlo data.

Findings

Jet radii are independent of collision energy.

Quark-jets have larger radii than gluon-jets.

Jet radii remain constant after parton evolution.

Abstract

The energy dependence of the radii size of jets are studied in detail by the HBT correlation method using Monte Carlo Simulation generator Jetset7.4 to produce 40,000,000 events of e$^+$e$^-$ collisions at $\sqrt s =30$, 50, 70, 91.2, 110, 130, 150 and 170 GeV. The radii of jets are measured using the HBT correlation method with the indistinguishability of identical final state pions. It is found that the average radii of quark-jets and gluon-jets are independent of the c.m. energy of e$^+$e$^-$ collisions. The average radius of quark-jets are obviously larger than that of gluon-jets. The invariable average radii of quark-jets and gluon-jets in e$^+$e$^-$ collisions are obtained at the end of parton evolvement.