A measurement of the tau lepton lifetime

California Institute of Technology
University of Oklahoma
San Diego University of California
Syracuse University
University of Minnesota Twin Cities
Santa Barbara University of California
Carnegie Mellon University
University of Rochester
Southern Methodist University
Lawrence University of Kansas
University of Florida
Ithaca College
Harvard University
University at Albany State University of New York
Cornell University
Purdue University
Ohio State University
Vanderbilt University
University of Colorado at Boulder

Abstract

Using τ + τ − pairs in which one τ decays to leptons and the other decays to 3 charged particles we present a high statistics measurement of the τ lepton lifetime. The data used in this analysis were collected with the CLEO detector at CESR and consist of an integrated luminosity of 429 pb −1 taken at, above, and below the ϒ (4S). We use the vertex displacements of the 3 charged tracks to determine the τ lifetime and measure it to be (3.04 ± 0.14 ± 0.07) × 10 −13 s .