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A measurement of the ratio of the branching fractions of the B(+) → K(+)μ(+)μ(-) and B(+) → K(+)e(+)e(-) decays is presented using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), recorded with the LHCb experiment at center-of-mass energies of 7 and 8 TeV. The value of the ratio of branching fractions for the dilepton(More)
Three jet events arising from decays of the Z bo-son, collected by the DELPHI detector, were used to measure differences in quark and gluon fragmentation. Gluon jets were anti-tagged by identifying b quark jets. Unbiased quark jets came from events with two jets plus one photon. Quark and gluon jet properties in different energy ranges were compared for the(More)
Observations of exotic structures in the J/ψp channel, which we refer to as charmonium-pentaquark states, in Λ_{b}^{0}→J/ψK^{-}p decays are presented. The data sample corresponds to an integrated luminosity of 3 fb^{-1} acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis of the three-body final state reproduces the two-body(More)
A search for the lepton-flavor-violating decays B(s)0→e(±)μ(∓) and B0→e(±)μ(∓) is performed with a data sample, corresponding to an integrated luminosity of 1.0 fb(-1) of pp collisions at √s=7 TeV, collected by the LHCb experiment. The observed number of B(s)0→e(±)μ(∓) and B0→e(±)μ(∓) candidates is consistent with background expectations. Upper limits on(More)
This Technical Design Report is dedicated to Tom Ypsilantis. Tom conceived the Ring Imaging Cherenkov detectors for particle identification in LHCb and he made an inestimable contribution to the LHCb RICH project. Tom would have wished to see these detectors in operation. He was totally dedicated to the project. He will be missed by the RICH group for his(More)
Measurement of ψ(2S) meson production in pp collisions at √ s = 7 TeV Abstract The differential cross-section for the inclusive production of ψ(2S) mesons in pp collisions at √ s = 7 TeV has been measured with the LHCb detector. The data sample corresponds to an integrated luminosity of 36 pb −1. The ψ(2S) mesons are reconstructed in the decay channels(More)
The ratio of the Λb(0) baryon lifetime to that of the B(0) meson is measured using 1.0  fb(-1) of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The Λb(0) baryon is observed for the first time in the decay mode Λb(0)→J/ψpK-, while the B(0) meson decay used is the well known B(0)→J/ψπ+ K- mode, where the π+ K- mass is(More)