Determination of the top-quark pole mass and strong coupling constant from the t t-bar production cross section in pp collisions at sqrt(s) = 7 TeV
ArXiv 1307.1907 (2013)
A signature-based search for delayed photons in exclusive photon plus missing transverse energy events from $p \bar{p}$ collisions with $\sqrt{s} = 1.96$ TeV
(2013)
A signature-based search for delayed photons in exclusive photon plus missing transverse energy events from $p \bar{p}$ collisions with $\sqrt{s} = 1.96$ TeV
ArXiv 1307.0474 (2013)
Abstract:
We present the first signature-based search for delayed photons using an exclusive photon plus missing transverse energy final state. Events are reconstructed in a data sample from the CDF II detector corresponding to $6.3 \text{fb}^{-1}$ of integrated luminosity from $\sqrt{s}=1.96$ TeV proton-antiproton collisions. Candidate events are selected if they contain a photon with an arrival time in the detector larger than expected from a promptly-produced photon. The mean number of events from standard model sources predicted by the data-driven background model based on the photon timing distribution is $286 \pm 24$. A total of 322 events are observed. A $p$-value of 12% is obtained, showing consistency of the data with standard model predictions.Measurement of masses in the tt̄ system by kinematic endpoints in pp collisions at √s = 7 TeV
European Physical Journal C 73:7 (2013) 1-28
Abstract:
A simultaneous measurement of the top-quark, W-boson, and neutrino masses is reported for tt̄ events selected in the dilepton final state from a data sample corresponding to an integrated luminosity of 5.0 fb-1 collected by the CMS experiment in pp collisions at √s = 7 TeV. The analysis is based on endpoint determinations in kinematic distributions. When the neutrino and W-boson masses are constrained to their world-average values, a top-quark mass value of Mt = 173.9 ± 0.9 (stat)+1.7-2.1(syst.) GeV is obtained. When such constraints are not used, the three particle masses are obtained in a simultaneous fit. In this unconstrained mode the study serves as a test of mass determination methods that may be used in beyond standard model physics scenarios where several masses in a decay chain may be unknown and undetected particles lead to underconstrained kinematics. © 2013 CERN for the benefit of the CMS collaboration.Search for physics beyond the standard model in events with τ leptons, jets, and large transverse momentum imbalance in pp collisions at √s = 7 TeV
European Physical Journal C 73:7 (2013) 1-26