Search

A search for the decay B0S→K¯∗0μ+μ− is presented using data sets corresponding to 1.0, 2.0 and 1.6 fb−1 of integrated luminosity collected during pp collisions with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, respectively. An excess is found over the background-only hypothesis with a significance of 3.4 standard deviations. The branching fraction of the B0S→K¯∗0μ+μ− decay is determined to be B(B0s→K¯∗0μ+μ−)=[2.9±1.0(stat)±0.2(syst)±0.3(norm)]×10−8, where the first and second uncertainties are statistical and systematic, respectively. The third uncertainty is due to limited knowledge of external parameters used to normalise the branching fraction measurement. SI

The B¯0s→χc2K+K− decay mode is observed and its branching fraction relative to the corresponding χc1 decay mode, in a ±15 MeV/c2 window around the ϕ mass, is found to be B(B¯0s→χc2K+K−)B(B¯0s→χc1K+K−)=(17.1±3.1±0.4±0.9)%, where the first uncertainty is statistical, the second systematic and the third due to the knowledge of the branching fractions of radiative χc decays. The decay mode B¯0s→χc1K+K− allows the B0s mass to be measured as m(B0s)=5366.83±0.25±0.27 MeV/c2, where the first uncertainty is statistical and the second systematic. A combination of this result with other LHCb determinations of the B 0s mass is made. SI

The charmless three-body decays B 0( s) → K0Sh+h′ − (where h(′) = π, K) are analysed using a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3 fb−1. The branching fractions are measured relative to that of the B0 → K0Sπ+π− decay, and are determined to be: B(B0→K0SK±π∓)B(B0→K0SK+π−)=0.123±0.009(stat)±0.015(syst),B(B0→K0SK+K−)B(B0→K0Sπ+π−)=0.549±0.018(stat)±0.033(syst),B(B0s→K0Sπ+π−)B(B0→K0Sπ+π−)=0.191±0.027(stat)±0.031(syst)±0.011(fs/fd),B(B0s→K0SK±π∓)B(B0→K0Sπ+π−)=1.70±0.07(stat)±0.11(syst)±0.10(fs/fd),B(B0s→K0SK+K−)B(B0→K0Sπ+π−)∈[0.008−0.051]at 90% confidencelevel, where fs/fd represents the ratio of hadronisation fractions of the B0s and B0 mesons. SI

A study of B0s → η c ϕ and B0s → η c π + π − decays is performed using pp collision data corresponding to an integrated luminosity of 3.0 fb−1, collected with the LHCb detector in Run 1 of the LHC. The observation of the decay B 0s → η c ϕ is reported, where the η c meson is reconstructed in the pp¯, K + K − π + π −, π + π − π + π − and K + K − K + K − decay modes and the ϕ(1020) in the K + K − decay mode. The decay B 0s → J/ψϕ is used as a normalisation channel. Evidence is also reported for the decay B 0s → η c π + π −, where the η c meson is reconstructed in the pp¯decay mode, using the decay B 0s → J/ψπ + π − as a normalisation channel. The measured branching fractions are B(B0s→ηcϕ)=(5.01±0.53±0.27±0.63)×10−4,B(B0s→ηcπ+π−)=(1.76±0.59±0.12±0.29)×10−4, where in each case the first uncertainty is statistical, the second systematic and the third uncertainty is due to the limited knowledge of the external branching fractions. SI

A measurement is presented of decay-time-dependent CP violation in the decays B0 → J/ψ K 0S and B0 → ψ(2S)K 0S, where the J/ψ is reconstructed from two electrons and the ψ(2S) from two muons. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. The CP -violation observables are measured to be C(B0→J/ψK0S)=0.12±0.07±0.02,S(B0→J/ψK0S)=0.83±0.08±0.01,C(B0→ψ(2S)K0S)=−0.05±0.10±0.01,S(B0→ψ(2S)K0S)=0.84±0.10±0.01, where C describes CP violation in the direct decay, and S describes CP violation in the interference between the amplitudes for the direct decay and for the decay after B0−B¯0 oscillation. The first uncertainties are statistical and the second are systematic. The two sets of results are compatible with the previous LHCb measurement using B0 → J/ψ K 0S decays, where the J/ψ meson was reconstructed from two muons. The averages of all three sets of LHCb results are C(B0→[cc¯]K0S)=−0.017±0.029,S(B0→[cc¯]K0S)=0.760±0.034, under the assumption that higher-order contributions to the decay amplitudes are negligible. The uncertainties include statistical and systematic contributions. SI

The decays Λ0b → ψ(2S)pK− and Λ0b → J/ψπ + π −pK− are observed in a data sample corresponding to an integrated luminosity of 3 fb−1, collected in proton-proton collisions at 7 and 8 TeV centre-of-mass energies by the LHCb detector. The ψ(2S) mesons are reconstructed through the decay modes ψ(2S) → μ+μ− and ψ(2S) → J/ψπ + π −. The branching fractions relative to that of Λ0b → J/ψpK− are measured to be B(Λ0b→ψ(2S)pK−)B(Λ0b→J/ψpK−)=(20.70±0.76±0.46±0.37)×10−2, where the first uncertainties are statistical, the second are systematic and the third is related to the knowledge of J/ψ and ψ(2S) branching fractions. The mass of the Λ 0b baryon is measured to be M(Λ0b)=5619.65±0.17±0.17 MeV/c2, where the uncertainties are statistical and systematic. SI

Measurements of the differential branching fraction and angular moments of the decay B 0 → K +π− μ + μ − in the K +π− invariant mass range 1330 < m(K +π−) < 1530 MeV/c 2 are presented. Proton-proton collision data are used, corresponding to an integrated luminosity of 3 fb−1 collected by the LHCb experiment. Differential branching fraction measurements are reported in five bins of the invariant mass squared of the dimuon system, q 2, between 0.1 and 8.0 GeV2 /c 4. For the first time, an angular analysis sensitive to the S-, P- and D-wave contributions of this rare decay is performed. The set of 40 normalised angular moments describing the decay is presented for the q 2 range 1.1-6.0 GeV2 /c 4. SI

A binned Dalitz plot analysis of the decays B 0 → DK ∗0, with D → K 0S π + π − and D → K 0S K + K −, is performed to measure the observables x ± and y ±, which are related to the CKM angle γ and the hadronic parameters of the decays. The D decay strong phase variation over the Dalitz plot is taken from measurements performed at the CLEO-c experiment, making the analysis independent of the D decay model. With a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment, the values of the CP violation parameters are found to be x + = 0.05 ± 0.35 ± 0.02, x − = −0.31 ± 0.20 ± 0.04, y + = −0.81 ± 0.28 ± 0.06 and y − = 0.31 ± 0.21 ± 0.05, where the first uncertainties are statistical and the second systematic. These observables correspond to values γ = (71 ± 20)°, rB0=0.56±0.17 and δB0=(204+21−20)∘. The parameters rB0 and δB0 are the magnitude ratio and strong phase difference between the suppressed and favoured B 0 decay amplitudes, and have been measured in a region of ±50 MeV/c 2 around the K ∗(892)0 mass and with the magnitude of the cosine of the K ∗(892)0 helicity angle larger than 0.4. SI

A model-dependent amplitude analysis of the decay B 0 → D(K 0S π + π −)K ∗ 0 is performed using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb−1, recorded at √s=7 and 8 TeV by the LHCb experiment. The CP violation observables x ± and y ±, sensitive to the CKM angle γ, are measured to be x−=−0.15±0.14±0.03±0.01,y−=0.25±0.15±0.06±0.01,x+=0.05±0.24±0.04±0.01,y+=−0.65+0.24−0.23±0.08±0.01, where the first uncertainties are statistical, the second systematic and the third arise from the uncertainty on the D → K 0S π + π − amplitude model. These are the most precise measurements of these observables. They correspond to γ = (80 + 21− 22)° and rB0=0.39±0.13, where rB0 is the magnitude of the ratio of the suppressed and favoured B 0 → DK + π − decay amplitudes, in a Kπ mass region of ±50 MeV around the K *(892)0 mass and for an absolute value of the cosine of the K *0 decay angle larger than 0.4. SI

The first measurement of CP asymmetries in the decay B0s→J/ψK∗(892)0 and an updated measurement of its branching fraction and polarisation fractions are presented. The results are obtained using data corresponding to an integrated luminosity of 3.0 fb−1 of proton-proton collisions recorded with the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Together with constraints from B 0 → J/ψ ρ 0, the results are used to constrain additional contributions due to penguin diagrams in the CP -violating phase ϕ s , measured through B 0s decays to charmonium. SI