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A bstract A measurement of the production cross-section of Z bosons in pp collisions at s = 13 TeV is presented using dimuon and dielectron final states in LHCb data. The cross-section is measured for leptons with pseudorapidities in the range 2 . 0 < η < 4 . 5, transverse momenta p T > 20 GeV and dilepton invariant mass in the range 60 < m ( ℓℓ ) < 120 GeV. The integrated cross-section from averaging the two final states is σ Z ℓℓ  = 194.3 ± 0.9 ± 3.3 ± 7.6 pb , where the first uncertainty is statistical, the second is due to systematic effects, and the third is due to the luminosity determination. In addition, differential cross-sections are measured as functions of the Z boson rapidity, transverse momentum and the angular variable ϕ η * .

A bstract A measurement of the differential branching fraction of the decay B 0 → K ∗ (892) 0 μ + μ − is presented together with a determination of the S-wave fraction of the K + π − system in the decay B 0 → K + π − μ + μ − . The analysis is based on pp -collision data corresponding to an integrated luminosity of 3 fb −1 collected with the LHCb experiment. The measurements are made in bins of the invariant mass squared of the dimuon system, q 2 . Precise theoretical predictions for the differential branching fraction of B 0 → K ∗ (892) 0 μ + μ − decays are available for the q 2 region 1 . 1 < q 2 < 6 . 0 GeV 2 /c 4 . In this q 2 region, for the K + π − invariant mass range 796 < m Kπ < 996 MeV /c 2 , the S-wave fraction of the K + π − system in B 0 → K + π − μ + μ − decays is found to be F S = 0.101 ± 0.017 stat ± 0.009 syst , and the differential branching fraction of B 0 → K ∗ (892) 0 μ + μ − decays is determined to be d ℬ / d q 2 = 0 . 392 − 0.019 + 0.020 stat ± 0.010 syst ± 0.027 norm × 1 0 − 7 c 4 / GeV 2 . The differential branching fraction measurements presented are the most precise to date and are found to be in agreement with Standard Model predictions.

A bstract The production of J/ψ mesons in proton-proton collisions at a centre-of-mass energy of s = 13 TeV is studied with the LHCb detector. Cross-section measurements are performed as a function of the transverse momentum p T and the rapidity y of the J/ψ meson in the region p T < 14 GeV/ c and 2 . 0 < y < 4 . 5, for both prompt J/ψ mesons and J/ψ mesons from b -hadron decays. The production cross-sections integrated over the kinematic coverage are 15 . 30 ± 0 . 03 ± 0 . 86 μb for prompt J/ψ and 2 . 34 ± 0 . 01 ± 0 . 13 μb for J/ψ from b -hadron decays, assuming zero polarization of the J/ ψ meson. The first uncertainties are statistical and the second systematic. The cross-section reported for J/ψ mesons from b -hadron decays is used to extrapolate to a total b b ¯ cross-section. The ratios of the cross-sections with respect to s = 8 TeV are also determined.

A bstract Associated production of bottomonia and open charm hadrons in pp collisions at s = 7 and 8 TeV is observed using data corresponding to an integrated luminosity of 3 fb −1 accumulated with the LHCb detector. The observation of five combinations, Y(1S)D 0 , Y(2S)D 0 , Y(1S)D + , Y(2S)D + and Y(1S)D s + , is reported. Production crosssections are measured for Y(1S)D 0 and Y(1S)D + pairs in the forward region. The measured cross-sections and the differential distributions indicate the dominance of double parton scattering as the main production mechanism.

A bstract A comprehensive study of the local and nonlocal amplitudes contributing to the decay B 0 → K *0 (→ K + π − ) μ + μ − is performed by analysing the phase-space distribution of the decay products. The analysis is based on pp collision data corresponding to an integrated luminosity of 8.4 fb − 1 collected by the LHCb experiment. This measurement employs for the first time a model of both one-particle and two-particle nonlocal amplitudes, and utilises the complete dimuon mass spectrum without any veto regions around the narrow charmonium resonances. In this way it is possible to explicitly isolate the local and nonlocal contributions and capture the interference between them. The results show that interference with nonlocal contributions, although larger than predicted, only has a minor impact on the Wilson Coefficients determined from the fit to the data. For the local contributions, the Wilson Coefficient C 9 , responsible for vector dimuon currents, exhibits a 2.1 σ deviation from the Standard Model expectation. The Wilson Coefficients C 10 , C 9 ′ and C 10 ′ are all in better agreement than C 9 with the Standard Model and the global significance is at the level of 1.5 σ . The model used also accounts for nonlocal contributions from B 0 → K *0 [ τ + τ − → μ + μ − ] rescattering, resulting in the first direct measurement of the bsττ vector effective-coupling C 9 τ .

A bstract A measurement of the cross-section for W → eν production in pp collisions is presented using data corresponding to an integrated luminosity of 2 fb −1 collected by the LHCb experiment at a centre-of-mass energy of s = 8 TeV. The electrons are required to have more than 20 GeV of transverse momentum and to lie between 2 . 00 and 4 . 25 in pseudorapidity. The inclusive W production cross-sections, where the W decays to eν , are measured to be σ W + → e + ν e = 1124.4 ± 2.1 ± 21.5 ± 11.2 ± 13.0 p b , σ W − → e − ν ¯ e = 809.0 ± 1.9 ± 18.1 ± 7.0 ± 9.4 p b , where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W + /W − cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of W boson branching fractions is determined to be ℬ W → e ν / ℬ W → μ ν = 1.020 ± 0.002 ± 0.019 , where the first uncertainty is statistical and the second is systematic.