Top-Charm Associated Production in High Energy e{sup +}e{sup -} Collisions

Abstract

The possibility of exploring the flavor changing neutral current tcZ/tc{gamma} couplings in the production vertex for the reaction e{sup +}e{sup -} {yields} t{bar c} + {bar t}c is examined. Using a model independent parameterization for the effective Lagrangian to describe the most general three-point interactions, production cross sections are found to be relatively small at LEP II, but potentially sizeable at higher energy e{sup +}e{sup -} colliders. The kinematic characteristics of the signal are studied and a set of cuts are devised for clean separation of the signal from background. The resulting sensitivity to anomalous flavor changing couplings at LEP II with an integrated luminosity of 4 x 500 pb{sup -1} is found to be comparable to their present indirect constraints from loop processes, while at higher energy colliders with 0.5-1 TeV center-of-mass energy and 50-200 fb{sup -1} luminosity, one expects to reach a sensitivity at or below the percentage level.