Measurements of the Cross Sections for Open Charm and Beauty Production in gamma gamma Collisions at root(s)=189-202 GeV

TL;DR

This paper measures the production cross sections of charm and beauty quarks in gamma-gamma collisions at LEP energies, finding the b production rate exceeds QCD predictions by a factor of three.

Contribution

First measurement of b quark production cross section in gamma-gamma collisions, comparing experimental results with QCD calculations at high energies.

Findings

Measured charm and beauty production cross sections.

Observed b production exceeds QCD predictions by a factor of three.

Provided new data for testing QCD in photon-photon interactions.

Abstract

The production of c and b quarks in gamma-gamma collisions is studied with the L3 detector at LEP with 410 pb^-1 of data, collected at centre-of-mass energies from 189 GeV to 202 GeV. Hadronic final states containing c and b quarks are identified by detecting electrons or muons from their semileptonic decays. The cross sections sigma(e+e- -> e+e- c c~ X) and sigma(e+e- -> e+e- b b~ X) are measured and compared to next-to-leading order perturbative QCD calculations. The cross section of b production is measured in gamma-gamma collisions for the first time. It is in excess of the QCD prediction by a factor of three.