Malcolm John

Abstract:

The first observation of the rare decay B0s to φπ+π- and evidence for B0 to φπ+π- are reported, using pp collision data recorded by the LHCb detector at centre-of-mass energies √s = 7 and 8 TeV, corresponding to an integrated luminosity of 3fb^-1. The branching fractions in the π+π- invariant mass range 400 < m(π+π-) < 1600 MeV/c2 are [3.48 ± 0.23 ± 0.17 ± 0.35] X 10^-6 and [1.82 ± 0.25 ± 0.41 ± 0.14] X 10^-7 for B0s to φπ+π- and B0 to φπ+π- respectively, where the uncertainties are statistical, systematic and from the normalisation mode B0s to φπ+π-. A combined analysis of the π+π- mass spectrum and the decay angles of the final-state particles identifies the exclusive decays B0s to φf0(980), B0s to φf2(1270), and B0s →ϕρ0 with branching fractions of [1.12 ± 0.16^+0.09-0.08 ± 0.11] X 10^-6, [0.61 ± 0.13^+0.12-0.05 ± 0.06] X 10^-6 and [2.7 ± 0.7 ± 0.2 ± 0.2] X 10^-7, respectively.

Abstract:

A combination of measurements sensitive to the CKM angle γ from LHCb is performed. The inputs are from analyses of time-integrated B+ → DK+, B0 → DK∗0, B0 → DK+π− and B+ → DK+π+π− tree-level decays. In addition, results from a time-dependent analysis of Bs0 → Ds∓K± decays are included. The combination yields γ = (72. 2− 7.3+ 6.8)°, where the uncertainty includes systematic effects. The 95.5% confidence level interval is determined to be γ ∈ [55.9, 85.2]°. A second combination is investigated, also including measurements from B+ → Dπ+ and B+ → Dπ+π−π+ decays, which yields compatible results.

Abstract:

Measurements of the differential branching fraction and angular moments of the decay $B^0 \to K^+ \pi^- \mu^+ \mu^-$ in the $K^*_{0,2}(1430)^0$ in the $K^+\pi^-$ invariant mass range $1330

Abstract:

The CP violation observables S and C in the decay channel B⁰ → D⁺ D⁻ are determined from a sample of proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3 fb^-1. The observable S describes CP violation in the interference between mixing and the decay amplitude, and C parametrizes direct CP violation in the decay. The following values are obtained from a flavour-tagged, decay-time-dependent analysis:

S = -0.54+0:17-0:16 (stat) ± 0:05 (syst) ;

C = 0:26+0:18-0:17 (stat) ± 0:02 (syst) :

These values constrain higher-order Standard Model corrections to be small

Abstract:

A search is made for the highly-suppressed B meson decays B+ → K+K+π- and B+ → π+π+K- using a data sample corresponding to an integrated luminosity of 3.0 fb^-1 collected by the LHCb experiment in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. No evidence is found for the decays, and upper limits at 90% confidence level are determined to be B(B+ → K+K+π-) < 1.1 X 10^-8 and B+ → π+π+K-) < 4.6 X 10^-8.