© 2017 CERN. A search for the decays Bc+→J/ψD(∗)0K+ and Bc+→J/ψD(∗)+K∗0 is performed with data collected at the LHCb experiment corresponding to an integrated luminosity of 3 fb-1. The decays Bc+→J/ψD0K+ and Bc+→J/ψD∗0K+ are observed for the first time, while first evidence is reported for the Bc+→J/ψD∗+K∗0 and Bc+→J/ψD+K∗0 decays. The branching fractions of these decays are determined relative to the Bc+→J/ψπ+ decay. The Bc+ mass is measured, using the J/ψD0K+ final state, to be 6274.28±1.40(stat)±0.32(syst) MeV/c2. This is the most precise single measurement of the Bc+ mass to date.

© 2018, The Author(s). A search for the lepton-flavour violating decays Bs0 → e±μ∓ and B0 → e±μ∓ is performed based on a sample of proton-proton collision data corresponding to an integrated luminosity of 3 fb−1, collected with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The observed yields are consistent with the background-only hypothesis. Upper limits on the branching fraction of the Bs0 → e±μ∓ decays are evaluated both in the hypotheses of an amplitude completely dominated by the heavy eigenstate and by the light eigenstate. The results are @@ℬ(Bs0→e)<6.3(5.4)×10−9 and @@ℬ(Bs0→e)<7.2(6.0)×10−9 at 95% (90%) confidence level, respectively. The upper limit on the branching fraction of the B0 → e±μ∓ decay is also evaluated, obtaining @@ℬ(B0→e)<1.3(1.0)×10−9 at 95% (90%) confidence level. These are the strongest limits on these decays to date.[Figure not available: see fulltext.].

© 2016, The Author(s). The ratio of branching fractions RK/π≡ℬ(Bc+→J/ψK+)/ℬ(Bc+→J/ψπ+) is measured with pp collision data collected by the LHCb experiment at centre-of-mass energies of 7 TeV and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. It is found to be RK/π = 0.079 ± 0.007 ± 0.003, where the first uncertainty is statistical and the second is systematic. This measurement is consistent with the previous LHCb result, while the uncertainties are significantly reduced.[Figure not available: see fulltext.]

© 2017 CERN. Decays of B0 and Bs0 mesons to the charmless baryonic final states pp-h+h′-, where h and h′ each denote a kaon or a pion, are searched for using the LHCb detector. The analysis is based on a sample of proton-proton collision data collected at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1. Four-body charmless baryonic Bs0 decays are observed for the first time. The decays Bs0→pp-K+K-, Bs0→pp-K±πâ", B0→pp-K±πâ" and B0→pp-π+π-A re observed with a significance greater than 5 standard deviations; evidence at 4.1 standard deviations is found for the B0→pp-K+K-decay and an upper limit is set on the branching fraction for Bs0→pp-π+π-. Branching fractions in the kinematic region m(pp-)<2850 MeV/c2 are measured relative to the B0→J/ψ(→pp-)K∗(892)0 channel.

© 2017 The Author(s) A search for time-integrated CP violation in the Cabibbo-suppressed decay D0→π+π−π+π− is performed using an unbinned, model-independent technique known as the energy test. This is the first application of the energy test in four-body decays. The search is performed for P-even CP asymmetries and, for the first time, is extended to probe the P-odd case. Using proton–proton collision data corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb detector at centre-of-mass energies of s=7 TeV and 8 TeV, the world's best sensitivity to CP violation in this decay is obtained. The data are found to be consistent with the hypothesis of CP symmetry with a p-value of (4.6±0.5)% in the P-even case, and marginally consistent with a p-value of (0.6±0.2)% in the P-odd case, corresponding to a significance for CP non-conservation of 2.7 standard deviations.

© 2018 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the »https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP 3 . The ratio of branching fractions R(D∗-)≡B(B0→D∗-τ+ντ)/B(B0→D∗-μ+νμ) is measured using a data sample of proton-proton collisions collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb-1. The τ lepton is reconstructed with three charged pions in the final state. A novel method is used that exploits the different vertex topologies of signal and backgrounds to isolate samples of semitauonic decays of b hadrons with high purity. Using the B0→D∗-π+π-π+ decay as the normalization channel, the ratio B(B0→D∗-τ+ντ)/B(B0→D∗-π+π-π+) is measured to be 1.97±0.13±0.18, where the first uncertainty is statistical and the second systematic. An average of branching fraction measurements for the normalization channel is used to derive B(B0→D∗-τ+ντ)=(1.42±0.094±0.129±0.054)%, where the third uncertainty is due to the limited knowledge of B(B0→D∗-π+π-π+). A test of lepton flavor universality is performed using the well-measured branching fraction B(B0→D∗-μ+νμ) to compute R(D∗-)=0.291±0.019±0.026±0.013, where the third uncertainty originates from the uncertainties on B(B0→D∗-π+π-π+) and B(B0→D∗-μ+νμ). This measurement is in agreement with the Standard Model prediction and with previous measurements.

© 2017, The Author(s). A search for the charmless Bs0 → η′ϕ decay is performed using pp collision data collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. No signal is observed and upper limits on the Bs0 → η′ϕ branching fraction are set to 0.82 × 10−6 at 90% and 1.01 × 10−6 at 95% confidence level.[Figure not available: see fulltext.].

© 2017 CERN. The first full amplitude analysis of B+→J/ψφK+ with J/ψ→μ+μ-, φ→K+K- decays is performed with a data sample of 3 fb-1 of pp collision data collected at s=7 and 8 TeV with the LHCb detector. The data cannot be described by a model that contains only excited kaon states decaying into φK+, and four J/ψφ structures are observed, each with significance over 5 standard deviations. The quantum numbers of these structures are determined with significance of at least 4 standard deviations. The lightest has mass consistent with, but width much larger than, previous measurements of the claimed X(4140) state. The model includes significant contributions from a number of expected kaon excitations, including the first observation of the K∗(1680)+→φK+ transition.

© 2016, The Author(s). Measurements of the differential branching fraction and angular moments of the decay B0 → K+π−μ+μ− in the K+π− invariant mass range 1330 < m(K+π−) < 1530 MeV/c2 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, q2, between 0.1 and 8.0 GeV2/c4. 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 q2 range 1.1-6.0 GeV2/c4.

© 2017 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the «https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. The B± meson production asymmetry in pp collisions is measured using B+→D-0π+ decays. The data were recorded by the LHCb experiment during Run 1 of the LHC at center-of-mass energies of s=7 and 8 TeV. The production asymmetries, integrated over transverse momenta in the range 2