Search for a heavy gauge boson W' in the final state with an electron and large missing transverse energy in pp collisions at s=7 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 698:1 (2011) 21-39
Abstract:
A search for a heavy gauge boson W' has been conducted by the CMS experiment at the LHC in the decay channel with an electron and large transverse energy imbalance ETmiss, using proton-proton collision data corresponding to an integrated luminosity of 36 pb-1. No excess above standard model expectations is seen in the transverse mass distribution of the electron- ETmiss system. Assuming standard-model-like couplings and decay branching fractions, a W' boson with a mass less than 1.36 TeV/c2 is excluded at 95% confidence level. © 2011 CERN.Measurement of b hadron lifetimes in exclusive decays containing a J/Ï in pp collisions at âs=1.96 TeV.
Phys Rev Lett 106:12 (2011) 121804
Abstract:
We report on a measurement of b-hadron lifetimes in the fully reconstructed decay modes B(+)âJ/ÏK(+), Bâ°âJ/ÏK*(892)â°, Bâ°âJ/ÏK(s)â°, and Î(b)â°âJ/ÏÎâ° using data corresponding to an integrated luminosity of 4.3 fbâ»Âč, collected by the CDF II detector at the Fermilab Tevatron. The measured lifetimes are Ï(B(+))=[1.639±0.009(stat)±0.009(syst)] ps, Ï(Bâ°)=[1.507±0.010(stat)±0.008(syst)] ps, and Ï(Î(b)â°)=[1.537±0.045(stat)±0.014(syst)] ps. The lifetime ratios are Ï(B(+))/Ï(Bâ°)=[1.088±0.009(stat)±0.004(syst)] and Ï(Î(b)â°)/Ï(Bâ°)=[1.020±0.030(stat)±0.008(syst)]. These are the most precise determinations of these quantities from a single experiment.Search for high mass resonances decaying to muon pairs in âs=1.96 TeV pp collisions.
Phys Rev Lett 106:12 (2011) 121801
Abstract:
We present a search for a new narrow, spin-1, high mass resonance decaying to ÎŒ(+)ÎŒâ»+X, using a matrix-element-based likelihood and a simultaneous measurement of the resonance mass and production rate. In data with 4.6 fbâ»Âč of integrated luminosity collected by the CDF detector in pp collisions at âs=1960 GeV, the most likely signal cross section is consistent with zero at 16% confidence level. We therefore do not observe evidence for a high mass resonance and place limits on models predicting spin-1 resonances, including M>1071 GeV/cÂČ at 95% confidence level for a Z' boson with the same couplings to fermions as the Z boson.Measurement of b hadron lifetimes in exclusive decays containing a J/Ï in ppÌ collisions at âs=1.96TeV
Physical Review Letters 106:12 (2011)
Abstract:
We report on a measurement of b-hadron lifetimes in the fully reconstructed decay modes B+âJ/ÏK+, B0âJ/ ÏK*(892)0, B0âJ/ÏKs0, and Îb0âJ/ÏÎ0 using data corresponding to an integrated luminosity of 4.3fb-1, collected by the CDF II detector at the Fermilab Tevatron. The measured lifetimes are Ï(B+)=[1.639±0.009(stat)±0.009(syst)] ps, Ï(B0)=[1.507±0.010(stat)±0.008(syst)]ps, and Ï(Îb0)=[1.537±0.045(stat)±0.014(syst)]ps. The lifetime ratios are Ï(B+)/Ï(B0)=[1.088±0.009(stat)±0. 004(syst)] and Ï(Îb0)/Ï(B0)=[1.020±0.030(stat)±0. 008(syst)]. These are the most precise determinations of these quantities from a single experiment. © 2011 American Physical Society.Measurement of the Top Pair Production Cross Section in the Lepton + Jets Channel Using a Jet Flavor Discriminant
(2011)