Search for the Intermediate Vector Boson

Abstract

A search for the vector boson ($W$ particle), postulated as the mediator of the weak interaction, has been carried out by determining the intensity and polarization of muons originating very near the point of interaction of 28-GeV protons with nucleons. Bosons were not observed and the upper limit on the production cross section for $W\text{'}\mathrm{s}$ with masses between 2.0 and 4.5 GeV/${\mathit{c}}^2$ is $B\sigma \lesssim 6\times {10}^{-36\mathrm{}}$ ${\mathrm{cm}}^2$, where $B$ is the branching ratio for the $W$ decay to a muon and a neutrino.