Browsing Recerca by Author "CERN"
Now showing items 241-260 of 324
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Observation of the Λ 0 b → J/ψ pπ − decay
Badalov, Alexey; Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2014, Vol. 2014, No.7 (Juliol), 2014-07-22)The first observation of the Cabibbo-suppressed decay Λ 0 b → J/ψpπ − is reported using a data sample of proton-proton collisions at 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. A ... -
Observation of Two New Ξ−b Baryon Resonances
Badalov, Alexey; Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters , 2015, Vol. 114, No. 6 (Febrer), 2015-02-10)Two structures are observed close to the kinematic threshold in the Ξ0bπ− mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, recorded by ... -
Observation of X(3872) production in pp collisions at s√=7~TeV
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (The European Physical Journal C, 2012. Vol. 72, No. 5 (Maig), 2012-05-04)Using 34.7 pb−1 of data collected with the LHCb detector, the inclusive production of the X(3872) meson in pp collisions at s√=7~TeV is observed for the first time. Candidates are selected in the ... -
Observation of Z production in proton-lead collisions at LHCb
Badalov, Alexey; Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2014, Vol. 2014, No.8 (Agost), 2014-08-19)The first observation of Z boson production in proton-lead collisions at a centre-of-mass energy per proton-nucleon pair of sNN−−−−√ = 5 TeV is presented. The data sample corresponds to an integrated ... -
Observation of ¯B0(s)→J/ψ f1(1285) Decays and Measurement of the f1(1285) Mixing Angle
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2014, Vol. 112, No. 9 (Març), 2014-03-04)Decays of ¯B0s and ¯B0 mesons into J/ψ π+π−π+π− final states, produced in pp collisions at the LHC, are investigated using data corresponding to an integrated luminosity of 3 fb−1 collected with the ... -
Observations of B0 s → ψ(2S)η and B0 (s) → ψ(2S)π+π− decays
Abellan Beteta, Carlos; Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Nuclear Physics B, 2013, Vol. 871, No. 3, 2013-06)First observations of the B0s→ψ(2S)η,B0→ψ(2S)π+π− and B0s→ψ(2S)π+π− decays are made using a dataset corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment in proton–proton ... -
Opposite-side flavour tagging of B mesons at the LHCb experiment
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (The European Physical Journal C, 2012. Vol. 72, No. 6 (Juny), 2012-06-07)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 ... -
Optimization and calibration of the same-side kaon tagging algorithm using hadronic B0s decays in 2011 data
LHCb Collaboration - CERN (2012-11)We report on the optimization and calibration of the same-side kaon tagging algorithm using the decay B0s→D−π+s with 1.0~fb−1 of data from the LHCb 2011 physics run. After a data-driven optimization and ... -
Precise measurements of the properties of the B1(5721)0,+ and B *2 (5747)0,+ states and observation of B+,0π−,+ mass structures
Badalov, Alexey; Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2015, Vol. 2015, No.4 (Abril), 2015-04-07)Invariant mass distributions of B+π− and B0π+ combinations are investigated in order to study excited B mesons. The analysis is based on a data sample corresponding to 3.0 fb−1 of pp collision data, ... -
Precision luminosity measurements at LHCb
Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of Instrumentation, 2014, Vol. 9, 2014-12)Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy √ s. In this paper results are reported from the luminosity calibrations carried out ... -
Precision Measurement of CP Violation in B0S→J/ΨK+K− Decays
Badalov, Alexey; Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters , 2015, Vol. 114, No.4 (Gener), 2015-01-30)The time-dependent CP asymmetry in B0s→J/ψK+K− decays is measured using pp collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected with the LHCb detector at center-of-mass ... -
Precision measurement of D meson mass differences
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2013, Vol. 2013, No.6 (Juny), 2013-06-17)Using three- and four-body decays of D mesons produced in semileptonic b-hadron decays, precision measurements of D meson mass differences are made together with a measurement of the D 0 mass. The ... -
Precision measurement of the B+c meson mass
Calvo Gómez, Míriam; Camboni, Alessandro; Golobardes, Elisabet; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2020, 123, 2020-07)A precision measurement of the B+c meson mass is performed using proton- proton collision data collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to a total ... -
Precision measurement of the B0 s –B 0 s oscillation frequency with the decay B0 s → D − s π +
Abellan Beteta, Carlos; Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (New Journal of Physics, 2013, Vol. 15, 2013-05)A key ingredient to searches for physics beyond the Standard Model in B0 s mixing phenomena is the measurement of the B0 s – B 0 s oscillation frequency, which is equivalent to the mass difference 1ms ... -
Precision Measurement of the Mass and Lifetime of the Ξ0b Baryon
Badalov, Alexey; Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2014, Vol. 113, No. 3 (Juliol), 2014-07-15)Using a proton-proton collision data sample corresponding to an integrated luminosity of 3 fb−1 collected by LHCb at center-of-mass energies of 7 and 8 TeV, about 3800 Ξ0b→Ξ+cπ−, Ξ+c→pK−π+ signal decays ... -
Precision Measurement of the Mass and Lifetime of the Ξ0b Baryon
Badalov, Alexey; Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters , 2014, Vol. 113, No.3 (Juliol), 2014-07-15)Using a proton-proton collision data sample corresponding to an integrated luminosity of 3 fb−1 collected by LHCb at center-of-mass energies of 7 and 8 TeV, about 3800 Ξ0b→Ξ+cπ−, Ξ+c→pK−π+ signal decays ... -
Precision measurement of the ratio of the Λb0 to B¯0 lifetimes
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physics Letters B , 2014, Vol. 734, (Juny), 2014-06-27)The LHCb measurement of the lifetime ratio of the Λ0b to the B⎯⎯⎯0 meson is updated using data corresponding to an integrated luminosity of 3.0 fb−1 collected using 7 and 8 TeV centre-of-mass energy pp ... -
Precision measurement of the Ξ++cc mass
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2020, 49, 2020-02)A measurement of the Ξ++cc mass is performed using data collected by the LHCb experiment between 2016 and 2018 in pp collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated ... -
Production of J/ψ and Υ mesons in pp collisions at s√=8 TeV
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2013, Vol. 2013, No.6 (Juny), 2013-06-14)The production of J/ψ and Υ mesons in pp collisions at s√=8 TeV is studied with the LHCb detector. The J/ψ and Υ mesons are reconstructed in the μ + μ − decay mode and the signal yields are determined ... -
Prompt charm production inppcollisions at √s=7 TeV
Abellan Beteta, Carlos; Calvo Gómez, Míriam; Camboni, Alessandro; Domingo Bonal, Francesc; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Nuclear Physics B, 2013, Vol. 871, No. 1, 2013-06)Charm production at the LHC in pp collisions at √s=7 TeV is studied with the LHCb detector. The decays D0→K−π+,D+→K−π+π+,D∗+→D0(K−π+)π+,D+s→φ(K−K+)π+,Λ+c→pK−π+, and their charge conjugates are analysed ...