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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 calibration and performance of the opposite-side 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 /ψK + , B 0 → J /ψK * 0 and B 0 → D * − μ + ν μ decay modes with 0.37 fb −1 of data(More)
Measurement of the forward energy flow in pp collisions at √ s = 7 TeV Abstract The energy flow created in pp collisions at √ s = 7 TeV is studied within the pseudorapidity range 1.9 < η < 4.9 with data collected by the LHCb experiment. The measurements are performed for inclusive minimum-bias interactions , hard scattering processes and events with an(More)
A search is presented for long-lived particles with a mass between 25 and 50 GeV/c 2 and a lifetime between 1 and 200 ps in a sample of proton–proton collisions at a centre-of-mass energy of √ s = 7 TeV, corresponding to an integrated luminosity of 0.62 fb −1 , collected by the LHCb detector. The particles are assumed to be pair-produced by the decay of a(More)
An angular analysis of the decay J /ψ → μ + μ − is performed to measure the polarization of prompt J /ψ mesons produced in pp collisions at √ s = 7 TeV. The dataset corresponds to an integrated luminosity of 0.37 fb −1 collected with the LHCb detector. The measurement is presented as a function of transverse momentum, p T , and rapid-ity, y, of the J /ψ(More)
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(More)
Measurement of charged particle multiplicities and densities in pp collisions at √ s = 7 TeV in the forward region Abstract Charged particle multiplicities are studied in proton–proton collisions in the forward region at a centre-of-mass energy of √ s = 7 TeV with data collected by the LHCb detector. The forward spectrometer allows access to a kine-matic(More)
The oscillation frequency, m d , of B 0 mesons is measured using semileptonic decays with a D − or D * − meson in the final state. The data sample corresponds to 3.0 fb −1 of pp collisions, collected by the LHCb experiment at centre-of-mass energies √ s = 7 and 8 TeV. A combination of the two decay modes gives m d = (505.0 ± 2.1 ± 1.0) ns −1 , where the(More)
A search is presented for massive long-lived particles decaying into a muon and two quarks. The dataset consists of proton-proton interactions at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 1 and 2[Formula: see text], respectively. The analysis is performed assuming a set of production mechanisms with simple(More)
Measurement of relative branching fractions of B decays to ψ(2S) and J /ψ mesons Abstract The relative rates of B-meson decays into J /ψ and ψ(2S) mesons are measured for the three decay modes in pp collisions recorded with the LHCb detector. The ratios of branching fractions (B) are measured to be B(B + → ψ(2S)K +) B(B + → J /ψK +) = 0.594 ± 0.006(stat) ±(More)