First observation of B0s →D*s2 +Xμν̄- decays
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 698:1 (2011) 14-20
Abstract:
Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the semileptonic decays B0s→D+s+Xμν̄ and B0s→D0K+Xμν̄ are detected. Two structures are observed in the D0K+ mass spectrum at masses consistent with the known Ds1(2536)+ and Ds2*(2573)+ mesons. The measured branching fractions relative to the total B-s0 semileptonic rate are B(B0s→Ds2*+Xμν̄)/B(B0s→Xμν̄)=(3.3±1.0±0.4)%, and B(B0s→D+s1Xμν̄)/B(B0s→Xμν̄)=(5.4±1.2±0.5)%, where the first uncertainty is statistical and the second is systematic. This is the first observation of the D*+s2 state in B0s decays; we also measure its mass and width. © 2011 CERN.Measurement of V0 production ratios in pp collisions at s√ = 0.9 and 7TeV
Journal of High Energy Physics 2011:8 (2011)
Abstract:
The Ā/A and Ā/K0S production ratios are measured by the LHCb detector from 0.3 nb-1 of pp collisions delivered by the LHC at s√ = 0.9TeV and 1.8 nb-1 at s√ = 7TeV. Both ratios are presented as a function of transverse momentum, pT, and rapidity, y, in the ranges 0.15 < pT < 2.50GeV/c and 2.0 < y < 4.5. Results at the two energies are in good agreement as a function of rapidity loss, Δy = ybeam - y, and are consistent with previous measurements. The ratio Ā/A, measuring the transport of baryon number from the collision into the detector, is smaller in data than predicted in simulation, particularly at high rapidity. The ratio Ā/K0S , measuring the baryon-to-meson suppression in strange quark hadronisation, is significantly larger than expected.Measurement of the inclusive Φ cross-section in pp collisions at s=7 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 703:3 (2011) 267-273
Abstract:
The cross-section for inclusive Φ meson production in pp collisions at a centre-of-mass energy of s=7 TeV has been measured with the LHCb detector at the Large Hadron Collider. The differential cross-section is measured as a function of the Φ transverse momentum pT and rapidity y in the region 0.6Search for the rare decays Bs 0 → μ+μ- and B0 → μ+μ-
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 699:5 (2011) 330-340
Abstract:
A search for the decays Bs0 → μ+μ- and B0 → μ+μ- is performed with about 37 pb-1 of pp collisions at s√=7 TeV collected by the LHCb experiment at the Large Hadron Collider at CERN. The observed numbers of events are consistent with the background expectations. The resulting upper limits on the branching ratios are B(Bs0 → μ+μ-)<5.6×10-8 and B(B0 → μ+μ-)<1.5×10-8 at 95% confidence level. © 2011 CERN.D0-(D)over-bar0 mixing studies with the decays D0 → KS0K∓π±
PHYSICS LETTERS B 701:3 (2011) 353-356