Observation of Diffractive W Boson Production at the Tevatron

TL;DR

This paper reports the first observation of diffractive W boson production at the Tevatron, identifying a significant excess of events with rapidity gaps indicative of diffraction, and analyzing the quark contribution from the pomeron.

Contribution

It provides the first experimental evidence of diffractive W boson production and quantifies its ratio to non-diffractive production at Tevatron energies.

Findings

Significant excess of events with rapidity gaps attributed to diffraction

Diffractive to non-diffractive W production ratio is approximately 1.15%

Evidence suggests quarks from the pomeron participate in W production

Abstract

We report the first observation of diffractively produced W bosons. In a sample of W -> e nu events produced in p-barp collisions at sqrt{s}=1.8 TeV, we find an excess of events with a forward rapidity gap, which is attributed to diffraction. The probability that this excess is consistent with non-diffractive production is 1.1 10^{-4} (3.8 sigma). The relatively low fraction of W+Jet events observed within this excess implies that mainly quarks from the pomeron, which mediates diffraction, participate in W production. The diffractive to non-diffractive W production ratio is found to be R_W=(1.15 +/- 0.55)%.