Measurement of the jet width in gamma-gamma collisions and in e^+e^- annihilation process at TRISTAN

TL;DR

This study measures and compares jet widths in gamma-gamma collisions and e^+e^- annihilation at TRISTAN, revealing narrower jets in gamma-gamma collisions and a scaling behavior across different collision types.

Contribution

First measurement of jet width in gamma-gamma collisions at TRISTAN and comparison with e^+e^- annihilation, highlighting a scaling behavior across various collision processes.

Findings

Jet width narrows with increasing jet transverse energy.

Jet width in gamma-gamma collisions is narrower than in gamma p collisions at the same energy.

Jet width exhibits approximate scaling as a function of scaled transverse energy x_T.

Abstract

The shape of jets produced in (quasi-) real photon-photon collisions as well as in e^+e^- annihilation process has been studied with a cone jet finding algorithm, using the data taken with the TOPAZ detector at the TRISTAN e^+e^- collider at an average center-of-mass energy of 58 GeV. The results are presented in terms of the jet width as a function of the jet transverse energy(E^{jet}_T) as well as a scaled transverse jet energy, x_T(=2E^{jet}_T/root(s)). The jet width narrows as E^{jet}_T increases; however, at the same value of E^{jet}_T the jet width in gamma-gamma collisions at TRISTAN is significantly narrower than that in gamma p collisions at HERA. By comparing our results with the data in other reactions, it has been shown that the jet width in gamma-gamma, gamma p, p\bar{p} collisions as well as the e^+e^- annihilation process has an approximate scaling behavior as a function of x_T.