Search for new physics in the mu+mu+e/mu+met channel with a low-pT lepton threshold at the Collider Detector at Fermilab

Abstract

A search for new physics using three-lepton (trilepton) data collected with the CDF II detector and corresponding to an integrated luminosity of 976 pb-1 is presented. The standard model predicts a low rate of trilepton events, which makes some supersymmetric processes, such as chargino-neutralino production, measurable in this channel. The mu+mu+l signature is investigated, where l is an electron or a muon, with the additional requirement of large missing transverse energy. In this analysis, the lepton transverse momenta with respect to the beam direction (pT) are as low as 5 GeV/c, a selection that improves the sensitivity to particles which are light as well as to ones which result in leptonically decaying tau leptons. At the same time, this low-p_T selection presents additional challenges due to the non-negligible heavy-quark background at low lepton momenta. This background is measured with an innovative technique using experimental data. Several dimuon and trilepton control regions are investigated, and good agreement between experimental results and standard-model predictions is observed. In the signal region, we observe one three-muon event and expect 0.4+/-0.1 mu+mu+l events

17 pages, 10 figures, 5 tables

References in corpus (5)

• PYTHIA 6.4 Physics and Manual
• Measurement of the Top Quark Mass using Template Methods on Dilepton Events in Proton-Antiproton Collisions at sqrt(s)=1.96 TeV
• Track Extrapolation and Distribution for the CDF-II Trigger System
• Search for chargino-neutralino production in p-pbar collisions at 1.96 TeV with high pT leptons
• Search for chargino-neutralino production in ppbar collisions at sqrt(s) = 1.96 TeV

Cited by in corpus (5)

• Constraining the MSSM with universal gaugino masses and implication for searches at the LHC
• Search for New Dielectron Resonances and Randall-Sundrum Gravitons at the Collider Detector at Fermilab
• Search for the supersymmetric partner of the top quark in ppbar collisions at sqrt(s) = 1.96 TeV
• Isolated leptons from heavy flavor decays: Theory and data
• Search for new physics in trilepton events and limits on the associated chargino-neutralino production at CDF