Author: Christopher B. Luchini

Publisher:

Published: 1994

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ISBN-13:

We have measured the production cross sections x decay branching ratios for W + $gamma$ and Z + $gamma$ in the muon channel in $sqrt{s}$ = 1.8 TeV p-p collisions, from 3.54 $pm$ 0.24 $pbsp{-1}$ of muon W and Z data from the CDF 1988-89 Tevatron collider run. For photons in the central region ($vertetavert $ 5.0 GeV and lepton-photon angular separation $Delta Rsb{ellsbgamma} >$ 0.7, 5 $Wsb{gamma}$ candidates and 2 $Zsb{gamma}$ candidates were observed. From these events, the $sigma cdot BR(W + gamma)$ and $sigma cdot BR(Z + gamma)$ cross sections for the muon samples are measured, and compared with Standard Model predictions. We also determined the cross section ratios, $Wsb{gamma}$/W, $Zsb{gamma}$/Z and $Wsb{gamma}/Zsb{gamma}$, which, along with the previous CDF measurement(s) of the W/Z cross section ratio provide new insight on the Standard Model, and are sensitive to anomalous couplings of the W and Z bosons. Using the $Wsb{gamma}$ and $Zsb{gamma}$ absolute cross section measurements, the absence of an excess of hard photons accompanying W and Z boson production enables us to obtain direct limites on anomalous $WWsb{gamma}$, $ZZsb{gamma}$ and $Zsb{gammagamma}$ couplings. For saturation of unitarity, these experimental limits impose constraints on possible internal (composite) structure for the W and Z bosons with compositeness scale sensitivity up to $Lambdasb{W} sim$ 1 TeV and $Lambdasb{Z} sim$ 250-500 GeV, respectively. These compositeness scale limits probe the possible internal structure of the W to ${sim}