Search for Neutral, Long-lived Particles Decaying into Two Muons in p-pbar Collisions at sqrt(s) = 1.96 TeV

TL;DR

This paper searches for long-lived neutral particles decaying into muon pairs in proton-antiproton collisions at 1.96 TeV, setting limits on their production and decay properties based on no observed candidates.

Contribution

It provides the first experimental limits on long-lived neutral particles decaying into muons at the Tevatron energy scale.

Findings

No candidate events observed.

Limits set on production cross section times branching fraction.

Results constrain interpretations of NuTeV's di-muon excess.

Abstract

We present a search for a neutral particle, pair-produced in p-pbar collisions at sqrt(s)=1.96 TeV, which decays into two muons and lives long enough to travel at least 5 cm before decaying. The analysis uses ~380 pb^-1 of data recorded with the D0 detector. The background is estimated to be about one event. No candidates are observed, and limits are set on the pair production cross section times branching fraction into dimuons + X for such particles. For a mass of 10 GeV and lifetime of 4x10^-11 s, we exclude values greater than 0.14 pb (95% C.L.). These results are used to limit the interpretation of NuTeV's excess of di-muon events.