Measurement of ϒ production in pp collisions at √s =7 TeV
European Physical Journal C 72:6 (2012)
Abstract:
The production of ϒ (1S), ϒ (2S) and ϒ (3S) mesons in proton-proton collisions at the centre-of-mass energy of √s = 7 TeV is studied with the LHCb detector. The analysis is based on a data sample of 25 pb−1 collected at the Large Hadron Collider. The ϒ mesons are reconstructed in the decay mode ϒ →μ + μ − and the signal yields are extracted from a fit to the μ + μ − invariant mass distributions. The differential production cross-sections times dimuon branching fractions are measured as a function of the ϒ transverse momentum pT and rapidity y, over the range pT < 15 GeV/c and 2.0Opposite-side flavour tagging of B mesons at the LHCb experiment
European Physical Journal C 72:6 (2012)
Abstract:
The calibration and performance of the opposites-ide flavour tagging algorithms used for the measurements of time-dependent asymmetries at the LHCb experiment are described. The algorithms have been developed using simulated events and optimized and calibrated with B + → J/ψ K + , B 0 →J/ψK* 0 and B 0 →D* − μ + ν μ decay modes with 0.37 fb −1 of data collected in pp collisions at √s = 7 TeV during the 2011 physics run. The opposite-side tagging power is determined in the B + → J/ψ K + channel to be (2.10 ± 0.08 ± 0.24) %, where the first uncertainty is statistical and the second is systematic.Observation of CP violation in B ±→DK ± decays
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 712:3 (2012) 203-212
Abstract:
An analysis of B ±→DK ± and B ±→Dπ ± decays is presented where the D meson is reconstructed in the two-body final states: K ±π ∓, K +K - and π +π -. Using 1.0 fb -1 of s=7TeV pp collisions, measurements of several observables are made including the first observation of the suppressed mode B±→[π±K∓]DK± CP violation in B ±→DK ± decays is observed with 5.8σ significance. © 2012 CERN.Observation of CP violation in B±→DK± decays
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 712:3 (2012) 203-212
Abstract:
An analysis of B±→DK± and B±→Dπ± decays is presented where the D meson is reconstructed in the two-body final states: K±π∓, K+K- and π+π-. Using 1.0 fb-1 of s=7TeV pp collisions, measurements of several observables are made including the first observation of the suppressed mode B±→[π±K∓]DK± CP violation in B±→DK± decays is observed with 5.8σ significance. © 2012 CERN.Strong constraints on the rare decays Bs0→μ +μ - and B0→μ +μ -
Physical Review Letters 108:23 (2012)