5 research outputs found
Measurement of the flavour-specific CP-violating asymmetry as sl in B0s decays
The CP  -violating asymmetry is studied using semileptonic decays of and mesons produced in pp  collisions at a centre-of-mass energy of 7 TeV at the LHC, exploiting a data sample corresponding to an integrated luminosity of 1.0 fbâ1. The reconstructed final states are , with the particle decaying in the Ïϱ mode. The yields are summed over and initial states, and integrated with respect to decay time. Data-driven methods are used to measure efficiency ratios. We obtain , where the first uncertainty is statistical and the second systematic
Searches for violation of lepton flavour and baryon number in tau lepton decays at LHCb
Searches for the lepton flavour violating decay ÏââÎŒâÎŒ+ÎŒâÏââÎŒâÎŒ+ÎŒâ and the lepton flavour and baryon number violating decays sourceÏââpÂŻÎŒ+ÎŒâ and ÏââpÎŒâÎŒâÏââpÎŒâÎŒâ have been carried out using protonâproton collision data, corresponding to an integrated luminosity of 1.0 fbâ11.0 fbâ1, taken by the LHCb experiment at s=7 TeV. No evidence has been found for any signal, and limits have been set at 90%90% confidence level on the branching fractions: B(ÏââÎŒâÎŒ+ÎŒâ)<8.0Ă10â8B(ÏââÎŒâÎŒ+ÎŒâ)<8.0Ă10â8, B(ÏââpÂŻÎŒ+ÎŒâ)<3.3Ă10â7 and B(ÏââpÎŒâÎŒâ)<4.4Ă10â7B(ÏââpÎŒâÎŒâ)<4.4Ă10â7. The results for the ÏââpÂŻÎŒ+ÎŒâ and ÏââpÎŒâÎŒâÏââpÎŒâÎŒâ decay modes represent the first direct experimental limits on these channels
Observation of B[0s Ïc1Ï decay and study of: B0 -> Ï c1,2K*1 decays
The first observation of the decay B0s â Ïc1Ï and a study of B0 â Ïc1,2K*0 decays are presented. The analysis is performed using a dataset, corresponding to an integrated luminosity of 1.0 fb-1, collected by the LHCb experiment in pp collisions at a centre-of-mass energy of 7 TeV. The following ratios of branching fractions are measured: Where the third uncertainty is due to the limited knowledge of the branching fractions of Ïc â J/ÏÎł modes. © 2013 CERN. Published by Elsevier B.V
Search for the rare decay
22 pages, 8 figures, Submitted to Physics Letters BA search for the rare decay is performed using a data sample, corresponding to an integrated luminosity of 0.9 fb, of collisions collected at a centre-of-mass energy of 7 TeV by the LHCb experiment. The observed number of events is consistent with the background expectations and corresponds to an upper limit of \mbox{} at \mbox{90%} \mbox{(95%)} confidence level. This result represents an improvement of more than a factor twenty with respect to previous measurements
Search for direct CP violation in D0 -> h- h+ modes using semileptonic B decays
15 pages, 4 figures - See paper for full list of authorsA search for direct CP violation in D0 -> h- h+ (where h=K or pi) is presented using data corresponding to an integrated luminosity of 1.0 fb^-1 collected in 2011 by LHCb in pp collisions at a centre-of-mass energy of 7 TeV. The analysis uses D0 mesons produced in inclusive semileptonic b-hadron decays to the D0 mu X final state, where the charge of the accompanying muon is used to tag the flavour of the D0 meson. The difference in the CP-violating asymmetries between the two decay channels is measured to be Delta A_CP = A_CP(K-K+) - A_CP(pi-pi+) = (0.49 +- 0.30 (stat) +- 0.14 (syst)) % . This result does not confirm the evidence for direct CP violation in the charm sector reported in other analyses