Listando Recerca por autor/a "CERN"
Mostrando ítems 34-53 de 324
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Evidence for the decay B0 → J/ψω and measurementof the relative branching fractions of B0s meson decays to J/ψη and J/ψη′
Abellan Beteta, Carlos; Calvo Gómez, Míriam; Camboni, Alessandro; Domingo Bonal, Francesc; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Nuclear Physics B, 2012, Vol. 867, No. 3, 2012-10)First evidence of the B0→J/ψω decay is found and the B0s→J/ψη and B0s→J/ψη′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experimentin ... -
Evidence for the decay X(3872) →ψ(2S)γ
Badalov, Alexey; Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Nuclear Physics B, 2014, Vol. 886, 2014-09)Evidence for the decay mode X(3872) →ψ(2S)γ in B+→X(3872)K+decays is found with a sig-nificance of 4.4 standard deviations. The analysis is based on a data sample of proton–proton collisions, corresponding ... -
Evidence for the Strangeness-Changing Weak Decay Ξ−b→Λ0bπ−
Badalov, Alexey; Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2015, Vol. 115, No. 24 (Desembre), 2015-12-11)Using a pp collision data sample corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb detector, we present the first search for the strangeness-changing weak decay Ξ−b→Λ0bπ−. ... -
Exclusive J/ψ and ψ(2S) production in pp collisions at √s= 7 TeV
Abellan Beteta, Carlos; Domingo Bonal, Francesc; Camboni, Alessandro; Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of Physics G-Nuclear and Particle Physics, 2013, Vol. 40, No. 4, 2013-02)Exclusive J/ψ and ψ(2S) vector meson production has been observed in the dimuon channel using the LHCb detector. The cross-section times branching fractions to two muons with pseudorapidities between ... -
First evidence for the annihilation decay mode B+→D+sφ
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2013, Vol. 2013, No.2 (Febrer), 2013-02-07)Evidence for the hadronic annihilation decay mode B+→D+sϕ is found with greater than 3σ significance. The branching fraction and CP asymmetry are measured to be $ B(B+→D+sϕ)=(1.87+1.25−0.73(stat)±0.1 ... -
First Evidence for the Decay B0s→μ+μ−
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2013, Vol. 110, No. 2 (Gener), 2013-01-07)A search for the rare decays B0s→μ+μ− and B0→μ+μ− is performed with data collected in 2011 and 2012 with the LHCb experiment at the Large Hadron Collider. The data samples comprise 1.1 fb−1 of proton-proton ... -
First evidence for the two-body charmless baryonic decay B0→pp¯¯¯
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2013, Vol. 2013, No.10 (Octubre), 2013-10-01)The results of a search for the rare two-body charmless baryonic decays B0→pp¯¯¯ and B0s→pp¯¯¯ are reported. The analysis uses a data sample, corresponding to an integrated luminosity of 0.9 fb−1, of ... -
First evidence of direct CP violation in charmless two-body decays of B0s mesons
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters , 2012, Vol. 108, No.20 (Maig), 2012-05-16)Using a data sample corresponding to an integrated luminosity of 0.35 fb−1 collected by LHCb in 2011, we report the first evidence of CP violation in the decays of B0s mesons to K±π∓ pairs, ... -
First Measurement of the Charge Asymmetry in Beauty-Quark Pair Production
Badalov, Alexey; Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2014, Vol. 113, No. 8 (Agosto), 2014-08-20)The difference in the angular distributions between beauty quarks and antiquarks, referred to as the charge asymmetry, is measured for the first time in b¯b pair production at a hadron collider. The ... -
First Measurement of the CP-Violating Phase in B0s→ϕϕ Decays
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2013, Vol. 110, No. 24 (Juny), 2013-06-12)A first flavor-tagged measurement of the time-dependent CP-violating asymmetry in B0s→ϕϕ decays is presented. In this decay channel, the CP-violating weak phase arises due to CP violation in the ... -
First measurement of time-dependent CP violation in B0s→K+K− decays
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2013, Vol. 2013, No.10 (Octubre), 2013-10-25)Direct and mixing-induced CP-violating asymmetries in B0s→K+K− decays are measured for the first time using a data sample of pp collisions, corresponding to an integrated luminosity of 1.0 fb−1, collected ... -
First observation and amplitude analysis of the B−→D+K−π− decay
Badalov, Alexey; Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review D, 2015, Vol.91, No.9 (Maig), 2015-05-05)The B−→D+K−π− decay is observed in a data sample corresponding to 3.0 fb−1 of pp collision data recorded by the LHCb experiment during 2011 and 2012. Its branching fraction is measured to be ... -
First observation and measurement of the branching fraction for the decay B 0 s → D ∗ s ∓ K ±
Badalov, Alexey; Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2015, Vol. 2015, No.6 (Juny), 2015-06-18)The first observation of the B 0 s → D ∗ s ∓ K ± decay is reported using 3.0 fb−1 of proton-proton collision data collected by the LHCb experiment. The D ∗ s ∓ mesons are reconstructed through the decay ... -
First Observation of a Baryonic B+c Decay
Badalov, Alexey; Calvo Gómez, Míriam; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2014, Vol. 113, No. 15 (Octubre), 2014-10-10)A baryonic decay of the B+c meson, B+c→J/ψp¯pπ+, is observed for the first time, with a significance of 7.3 standard deviations, in pp collision data collected with the LHCb detector and corresponding ... -
First observation of B0 → D∗+ Xμ−ν decays
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physics Letters B, Vol. 698, No. 1 (Març 2011), 2011)Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the semileptonic decays Bs -> Ds+ X mu nu and Bs -> D0 K+ X mu nu are detected. Two structures ... -
First observation of B0s → J/ψ f0(980) decays
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physics Letters B, Vol. 698, No 2 (Abril 2011), 2011-01)Using data collected with the LHCb detector in proton-proton collisions at a centre-of-mass energy of 7 TeV, the hadronic decayB0s→J/ψf0(980) is observed. ThisCP eigenstate mode could be used to measure ... -
First Observation of CP Violation in the Decays of B0s Mesons
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2013, Vol. 110, No. 22 (Maig), 2013-05-30)Using pp collision data corresponding to an integrated luminosity of 1.0 fb−1 and collected by LHCb in 2011 at a center-of-mass energy of 7 TeV, we report the measurement of direct CP violation in ... -
First Observation of Excited Ω−b States
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2020, Vol.124, 082002, 2020-02)We report four narrow peaks in the Ξ0bK− mass spectrum obtained using pp collisions at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb−1 recorded by ... -
First observation of the decay B+c → J/ψ K+
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Journal of High Energy Physics, 2013, Vol. 2013, No.9 (Setembre), 2013-09-13)The decay B+c→J/ψK+ is observed for the first time using a data sample, corresponding to an integrated luminosity of 1.0 fb−1, collected by the LHCb experiment in pp collisions at a centre-of-mass energy ... -
First Observation of the Decay B+c→J/ψπ+π−π+
Calvo Gómez, Míriam; Camboni, Alessandro; Vilasís Cardona, Xavier; LHCb Collaboration - CERN (Physical Review Letters, 2012, Vol. 108, No. 25 (Juny), 2012-06-19)The decay B+c→J/ψπ+π−π+ is observed for the first time, using 0.8 fb−1 of pp collisions at √s=7 TeV collected by the LHCb experiment. The ratio of branching fractions B(B+c→J/ψπ+π−π+)/B(B+c→J/ψπ+) is ...