Measurement of Charged-Particle Multiplicities in Gluon and Quark Jets in pp̅ Collisions at √s =1.8 TeV

Authors

Darin Acosta, University of FloridaFollow
Kenneth A. Bloom, University of Nebraska-LincolnFollow
Collider Detector at Fermilab Collaboration

Date of this Version

5-6-2005

Comments

Published by American Physical Society. Phys. Rev. Lett. 94, 171802 (2005) http://prl.aps.org. Copyright © 2005 American Physical Society. Permission to use.

Abstract

We report the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, N_q and N_g, produced at the Fermilab Tevatron in pp̅ collisions with a center-of-mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The measurements are made for jets with average energies of 41 and 53 GeV by counting charged particle tracks in cones with opening angles of θ _c=0.28, 0.36, and 0.47 rad around the jet axis. The corresponding jet hardness Q=E_jet θ _c varies in the range from 12 to 25 GeV. At Q=19.2 GeV, the ratio of multiplicities r=N_g/N_q is found to be 1.64±0.17, where statistical and systematic uncertainties are added in quadrature. The results are in agreement with resummed perturbative QCD calculations.