The charmless three-body decays B(s)0 → KS0h+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 → KS0π+π− decay, and are determined to be:ℬB0→KS0K±π∓ℬB0→KS0K+π−=0.123±0.009stat±0.015syst,ℬB0→KS0K+K−ℬB0→KS0π+π−=0.549±0.018stat±0.033syst,ℬBs0→KS0π+π−ℬB0→KS0π+π−=0.191±0.027stat±0.031syst±0.011fs/fd,ℬBs0→KS0K±π∓ℬB0→KS0π+π−=1.70±0.07stat±0.11syst±0.10fs/fd,ℬBs0→KS0K+K−ℬB0→KS0π+π−∈0.008−0.051at90%confidencelevel,where fs/fd represents the ratio of hadronisation fractions of the Bs0 and B0 mesons.
The first observation of the decays Λ_{b}^{0}→χ_{c1}pK^{-} and Λ_{b}^{0}→χ_{c2}pK^{-} is reported using a data sample corresponding to an integrated luminosity of 3.0 fb^{-1}, collected by the LHCb ...experiment in pp collisions at center-of-mass energies of 7 and 8 TeV. The following ratios of branching fractions are measured: B(Λ_{b}^{0}→χ_{c1}pK^{-})/B(Λ_{b}^{0}→J/ψpK^{-})=0.242±0.014±0.013±0.009,B(Λ_{b}^{0}→χ_{c2}pK^{-})/B(Λ_{b}^{0}→J/ψpK^{-})=0.248±0.020±0.014±0.009,B(Λ_{b}^{0}→χ_{c2}pK^{-})/B(Λ_{b}^{0}→χ_{c1}pK^{-})=1.02±0.10±0.02±0.05,where the first uncertainty is statistical, the second systematic, and the third due to the uncertainty on the branching fractions of the χ_{c1}→J/ψγ and χ_{c2}→J/ψγ decays. Using both decay modes, the mass of the Λ_{b}^{0} baryon is also measured to be m_{Λ_{b}^{0}}=5619.44±0.28±0.26 MeV/c^{2}, where the first and second uncertainties are statistical and systematic, respectively.
We report the first observation of a baryonic B_{s}^{0} decay, B_{s}^{0}→pΛover ¯K^{-}, using proton-proton collision data recorded by the LHCb experiment at center-of-mass energies of 7 and 8 TeV, ...corresponding to an integrated luminosity of 3.0 fb^{-1}. The branching fraction is measured to be B(B_{s}^{0}→pΛover ¯K^{-})+B(B_{s}^{0}→pover ¯ΛK^{+})=5.46±0.61±0.57±0.50(B)±0.32(f_{s}/f_{d})×10^{-6}, where the first uncertainty is statistical and the second systematic, the third uncertainty accounts for the experimental uncertainty on the branching fraction of the B^{0}→pΛover ¯π^{-} decay used for normalization, and the fourth uncertainty relates to the knowledge of the ratio of b-quark hadronization probabilities f_{s}/f_{d}.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract A test of lepton universality, performed by measuring the ratio of the branching fractions of the B 0 rarr K *0 mu ...+ mu - and B 0 rarr K *0 e + e - decays, ..., is presented. The K *0 meson is reconstructed in the final state K + pi -, which is required to have an invariant mass within 100 MeV/c 2 of the known K *(892)0 mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of about 3 fb-1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The ratio is measured in two regions of the dilepton invariant mass squared, q 2, to be ... The corresponding 95.4% confidence level intervals are 0.52, 0.89 and 0.53, 0.94. The results, which represent the most precise measurements of ... to date, are compatible with the Standard Model expectations at the level of 2.1-2.3 and 2.4-2.5 standard deviations in the two q 2 regions, respectively. Figure not available: see fulltext.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) The decays of B s 0 and ... mesons into the J/ψK + K − final state are studied in the K + K − mass region above the ϕ(1020) ...meson in order to determine the resonant substructure and measure the CP-violating phase, ϕ s , the decay width, Γ s , and the width difference between light and heavy mass eigenstates, ΔΓ s . A decay-time dependent amplitude analysis is employed. The data sample corresponds to an integrated luminosity of 3 fb−1 produced in 7 and 8 TeV pp collisions at the LHC, collected by the LHCb experiment. The measurement determines ϕ s = 119 ± 107 ± 34 mrad. A combination with previous LHCb measurements using similar decays into the J/ψπ + π − and J/ψϕ(1020) final states gives ϕ s = 1 ± 37 mrad, consistent with the Standard Model prediction. Figure not available: see fulltext.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) A study of B s 0 → η c ϕ and B s 0 → 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 s 0 → η c ϕ is reported, where the η c meson is reconstructed in the ..., 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 s 0 → J/ψϕ is used as a normalisation channel. Evidence is also reported for the decay B s 0 → η c π + π −, where the η c meson is reconstructed in the ... decay mode, using the decay B s 0 → J/ψπ + π − as a normalisation channel. The measured branching fractions are ... 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. Figure not available: see fulltext.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) The production cross-section of J/ψ pairs is measured using a data sample of pp collisions collected by the LHCb experiment ...at a centre-of-mass energy of ... TeV, corresponding to an integrated luminosity of 279 ±11 pb−1. The measurement is performed for J/ψ mesons with a transverse momentum of less than 10 GeV/c in the rapidity range 2.0 < y < 4.5. The production cross-section is measured to be 15.2 ± 1.0 ± 0.9 nb. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the J/ψ pair are measured and compared to theoretical predictions. Figure not available: see fulltext.
Asymmetries in the time-dependent rates of D^{0}→K^{+}K^{-} and D^{0}→π^{+}π^{-} decays are measured in a pp collision data sample collected with the LHCb detector during LHC Run 1, corresponding to ...an integrated luminosity of 3 fb^{-1}. The asymmetries in effective decay widths between D^{0} and Dover ¯^{0} decays, sensitive to indirect CP violation, are measured to be A_{Γ}(K^{+}K^{-})=(-0.30±0.32±0.10)×10^{-3} and A_{Γ}(π^{+}π^{-})=(0.46±0.58±0.12)×10^{-3}, where the first uncertainty is statistical and the second systematic. These measurements show no evidence for CP violation and improve on the precision of the previous best measurements by nearly a factor of two.
A search for the rare decays B_{s}^{0}→τ^{+}τ^{-} and B^{0}→τ^{+}τ^{-} is performed using proton-proton collision data collected with the LHCb detector. The data sample corresponds to an integrated ...luminosity of 3 fb^{-1} collected in 2011 and 2012. The τ leptons are reconstructed through the decay τ^{-}→π^{-}π^{+}π^{-}ν_{τ}. Assuming no contribution from B^{0}→τ^{+}τ^{-} decays, an upper limit is set on the branching fraction B(B_{s}^{0}→τ^{+}τ^{-})<6.8×10^{-3} at the 95% confidence level. If instead no contribution from B_{s}^{0}→τ^{+}τ^{-} decays is assumed, the limit is B(B^{0}→τ^{+}τ^{-})<2.1×10^{-3} at the 95% confidence level. These results correspond to the first direct limit on B(B_{s}^{0}→τ^{+}τ^{-}) and the world's best limit on B(B^{0}→τ^{+}τ^{-}).
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