La Salle: Enviaments recents
Ara mostrant els elements 521-540 de 737
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First Measurement of the Charge Asymmetry in Beauty-Quark Pair Production
(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 ... -
Test of Lepton Universality Using B+→K+ℓ+ℓ− Decays
(Physical Review Letters, 2014, Vol. 113, No. 15 (Octubre), 2014-10-06)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, ... -
Observation of the Resonant Character of the Z(4430)− State
(Physical Review Letters, 2014, Vol. 112, No. 22 (Juny), 2014-06-04)Resonant structures in B0→ψ′π−K+ decays are analyzed by performing a four-dimensional fit of the decay amplitude, using pp collision data corresponding to 3 fb−1 collected with the LHCb detector. The ... -
First Observation of the Decay B∗s2(5840)0→B*+K− and Studies of Excited B0s Mesons
(Physical Review Letters, 2013, Vol. 110, No. 15 (Abril), 2013-04-09)The properties of the orbitally excited (L=1) B0s states are studied by using 1.0 fb−1 of pp collisions at √s=7 TeV collected with the LHCb detector. The first observation of the B∗s2(5840)0 meson ... -
Evidence for CP Violation in B+→p¯pK+ Decays
(Physical Review Letters, 2014, Vol. 113, No. 14 (Octubre), 2014-09-20)Three-body B+→p¯pK+ and B+→p¯pπ+ decays are studied using a data sample corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb experiment in proton-proton collisions at center-of-mass ... -
First Measurement of the CP-Violating Phase in B0s→ϕϕ Decays
(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 ... -
Observation of Excited Λ0b Baryons
(Physical Review Letters, 2012, Vol. 109, No. 7 (Octubre), 2012-10-26)Using pp collision data corresponding to 1.0 fb−1 integrated luminosity collected by the LHCb detector, two narrow states are observed in the Λ0bπ+π− spectrum with masses 5911.97±0.12(stat)±0.02(syst ... -
Determination of the X(3872) Meson Quantum Numbers
(Physical Review Letters, 2013, Vol. 110, No. 22 (Maig), 2013-05-29)The quantum numbers of the X(3872) meson are determined to be JPC=1++ based on angular correlations in B+→X(3872)K+ decays, where X(3872)→π+π−J/ψ and J/ψ→μ+μ−. The data correspond to 1.0 fb−1 of pp ... -
Measurement of the ¯B0s→D−sD+s and ¯B0s→D−D+s Effective Lifetimes
(Physical Review Letters, 2014, Vol. 112, No. 11 (Març), 2014-03-19)The first measurement of the effective lifetime of the ¯B0s meson in the decay ¯B0s→D−sD+s is reported using a proton-proton collision data set, corresponding to an integrated luminosity of 3 fb−1, ... -
Observation of B0→¯¯¯D0K+K− and Evidence for B0s→¯¯¯D0K+K−
(Physical Review Letters, 2012, Vol. 109, No. 13 (Setembre), 2012-09-26)The first observation of the decay B0→¯¯¯D0K+K− is reported from an analysis of 0.62 fb−1 of pp collision data collected with the LHCb detector. Its branching fraction is measured relative to that of ... -
Observation of a Resonance in B+→K+μ+μ− Decays at Low Recoil
(Physical Review Letters, 2013, Vol. 111, No. 11 (Setembre), 2013-09-10)A broad peaking structure is observed in the dimuon spectrum of B+→K+μ+μ− decays in the kinematic region where the kaon has a low recoil against the dimuon system. The structure is consistent with ... -
Observation of the B0s→η′η′ Decay
(Physical Review Letters, 2015, Vol. 115, No. 5 (Juliol), 2015-07-28)The first observation of the B0s→η′η′ decay is reported. The study is based on a sample of proton-proton collisions corresponding to 3.0 fb−1 of integrated luminosity collected with the LHCb detector. ... -
Measurement of the Ratio of Branching Fractions B(¯B0→D*+τ−¯ντ)/B(¯B0→D*+μ−¯νμ)
(Physical Review Letters, 2015, Vol. 115, No. 11 (Setembre), 2015-09-09)The branching fraction ratio R(D∗)≡B(¯B0→D*+τ−¯ντ)/B(¯B0→D*+μ−¯νμ) is measured using a sample of proton-proton collision data corresponding to 3.0 fb−1 of integrated luminosity recorded by the LHCb ... -
First Observation of Top Quark Production in the Forward Region
(Physical Review Letters, 2015, Vol. 115, No. 11 (Setembre), 2015-09-08)Top quark production in the forward region in proton-proton collisions is observed for the first time. The W+b final state with W→μν is reconstructed using muons with a transverse momentum, pT, larger ... -
First Evidence for the Decay B0s→μ+μ−
(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 ... -
Observation of B(s)(0) → J/ψf(2)'(1525) in J/ψK+ K- final states
(Physical Review Letters, 2012, Vol. 108, No. 15 (Abril), 2012-04-09)The decay ¯¯¯B0s→J/ψK+K− is investigated using 0.16 fb−1 of data collected with the LHCb detector using 7 TeV pp collisions. Although the J/ψϕ channel is well known, final states at higher K+K− masses ... -
Evidence for CP Violation in Time-Integrated D0→h−h+ Decay Rates
(Physical Review Letters, 2012, Vol. 108, No. 11 (Març), 2012-03-12)A search for time-integrated CP violation in D0→h−h+ (h=K, π) decays is presented using 0.62 fb−1 of data collected by LHCb in 2011. The flavor of the charm meson is determined by the charge of the ... -
Observation of D0−¯¯¯D0 Oscillations
(Physical Review Letters, 2013, Vol. 110, No. 10 (Març), 2013-03-05)We report a measurement of the time-dependent ratio of D0→K+π− to D0→K−π+ decay rates in D*+-tagged events using 1.0 fb−1 of integrated luminosity recorded by the LHCb experiment. We measure the mixing ... -
Study of Beauty Hadron Decays into Pairs of Charm Hadrons
(Physical Review Letters, 2014, Vol. 112, No. 20 (Maig), 2014-05-21)First observations of the decays Λ0b→Λ+cD−(s) are reported using data corresponding to an integrated luminosity of 3 fb−1 collected at 7 and 8 TeV center-of-mass energies in proton-proton collisions ... -
Measurement of CP Violation in the Phase Space of B±→K±π+π− and B±→K±K+K− Decays
(Physical Review Letters, 2013, Vol. 111, No. 10 (Setembre), 2013-09-03)The charmless decays B±→K±π+π− and B±→K±K+K− are reconstructed using data, corresponding to an integrated luminosity of 1.0 fb−1, collected by LHCb in 2011. The inclusive charge asymmetries of these ...