A Measurement of the W to tau+nu Production Cross Section in p-pbar Collisions at sqrt(s) = 1.8 TeV

TL;DR

This paper measures the W boson production cross section times branching ratio to tau neutrinos in proton-antiproton collisions at 1.8 TeV, confirming lepton universality with high precision.

Contribution

It provides the first measurement of the W to tau+nu production cross section at the Tevatron and tests lepton universality in W decays.

Findings

Measured sigma*B(W to tau+nu) = 2.22 +- 0.09 (stat) +- 0.10 (syst) +- 0.10 (lum) nb.

Found the ratio of tau to electron W couplings g_tau^W / g_e^W = 0.980 +- 0.031, consistent with unity.

Abstract

We report on a measurement of sigma(p-pbar to W+X) times B(W to tau+nu) in p-pbar collisions at sqrt(s) = 1.8 TeV at the Fermilab Tevatron. The measurement is based on an integrated luminosity of 18 pb^-1 of data collected with the D0 detector during 1994-1995. We find that sigma(p-pbar to W+X) times B(W to tau+nu) = 2.22 +- 0.09 (stat) +- 0.10 (syst) +- 0.10 (lum) nb. Lepton universality predicts that the ratio of the tau and electron electroweak charged current couplings to the W boson, g_tau^W / g_e^W, be unity. We find g_tau^W / g_e^W = 0.980 +- 0.031, in agreement with lepton universality.