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Abstract The decays B+ → J/ψπ+π − K+ are studied using a data set corresponding to an integrated luminosity of 9 fb −1 collected with the LHCb detector in proton-proton collisions between 2011 and 2018. Precise measurements of the ratios of branching fractions with the intermediate ψ2(3823), χc1(3872) and ψ(2S) states are reported. The values are B B + → ψ 2 3823 K + × B ψ 2 3823 → J / ψπ + π − B B + → χ c 1 3872 K + × B χ c 1 3872 → J / ψπ + π − = 3.56 ± 0.67 ± 0.11 × 10 − 2 , B B + → ψ 2 3823 K + × B ψ 2 3823 → J / ψπ + π − B B + → ψ 2 S K + × B ψ 2 S → J / ψπ + π − = 1.31 ± 0.25 ± 0.04 × 10 − 3 , B B + → χ c 1 3872 K + × B χ c 1 3872 → J / ψπ + π − B B + → ψ 2 S K + × B ψ 2 S → J / ψπ + π − = 3.69 ± 0.07 ± 0.06 × 10 − 2 ,$$ {\\displaystyle \\begin{array}{c}\\frac{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to {\\uppsi}_2(3823){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\uppsi_2(3823)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to {\\upchi}_{\\mathrm{c}1}(3872){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\upchi_{\\mathrm{c}1}(3872)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}=\\left(3.56\\pm 0.67\\pm 0.11\\right)\\times {10}^{-2},\\\ {}\\frac{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to {\\uppsi}_2(3823){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\uppsi_2(3823)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to \\uppsi \\left(2\\mathrm{S}\\right){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\uppsi \\left(2\\mathrm{S}\\right)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}=\\left(1.31\\pm 0.25\\pm 0.04\\right)\\times {10}^{-3},\\\ {}\\frac{{\\mathcal{B}}_{\\mathrm{B}+\\to {\\upchi}_{\\mathrm{c}1}(3872){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\upchi_{\\mathrm{c}1}(3872)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}{{\\mathcal{B}}_{{\\mathrm{B}}^{+}\\to \\uppsi \\left(2\\mathrm{S}\\right){\\mathrm{K}}^{+}}\\times {\\mathcal{B}}_{\\uppsi \\left(2\\mathrm{S}\\right)\\to \\mathrm{J}/{\\uppsi \\uppi}^{+}{\\uppi}^{-}}}=\\left(3.69\\pm 0.07\\pm 0.06\\right)\\times {10}^{-2},\\end{array}} $$where the first uncertainty is statistical and the second is systematic. The decay of B+ → ψ2(3823)K+ with ψ2(3823) → J/ψπ+π − is observed for the first time with a significance of 5.1 standard deviations. The mass differences between the ψ2(3823), χc1(3872) and ψ(2S) states are measured to be m χ c 1 3872 − m ψ 2 3823 = 47.50 ± 0.53 ± 0.13 MeV / c 2 , m ψ 2 3823 − m ψ 2 2 S = 137.98 ± 0.53 ± 0.14 MeV / c 2 , m χ c 1 3872 − m ψ 2 2 S = 185.49 ± 0.06 ± 0.03 MeV / c 2 ,$$ {\\displaystyle \\begin{array}{c}{m}_{\\upchi_{\\mathrm{c}1}(3872)}-{m}_{\\uppsi_2(3823)}=47.50\\pm 0.53\\pm 0.13\\;\\mathrm{MeV}/{c}^2,\\\ {}{m}_{\\uppsi_2(3823)}-{m}_{\\uppsi_2\\left(2\\mathrm{S}\\right)}=137.98\\pm 0.53\\pm 0.14\\;\\mathrm{MeV}/{c}^2,\\\ {}{m}_{\\upchi_{\\mathrm{c}1}(3872)}-{m}_{\\uppsi_2\\left(2\\mathrm{S}\\right)}=185.49\\pm 0.06\\pm 0.03\\;\\mathrm{MeV}/{c}^2,\\end{array}} $$resulting in the most precise determination of the χc1(3872) mass. The width of the ψ2(3823) state is found to be below 5.2 MeV at 90% confidence level. The Breit-Wigner width of the χc1(3872) state is measured to be Γ χ c 1 3872 BW = 0.96 − 0.18 + 0.19 ± 0.21 MeV$$ {\\Gamma}_{\\upchi_{\\mathrm{c}1}(3872)}^{\\mathrm{BW}}={0.96}_{-0.18}^{+0.19}\\pm 0.21\\;\\mathrm{MeV} $$which is inconsistent with zero by 5.5 standard deviations.

A measurement of the CP-violating observables from B -> (DK +/-)-K-* and B-+/- -> D-*pi(+/-) decays is presented, where D-*(D) is an admixture of D-*0 and D-0 (D-0 and (0)) states and is reconstructed through the decay chains D-*-> D pi(0)/gamma and D -> KS0 pi+pi-/KS0K+K-. The measurement is performed by analysing the signal yield variation across the D decay phase space and is independent of any amplitude model. The data sample used was collected by the LHCb experiment in proton-proton collisions and corresponds to a total integrated luminosity of 9 fb(-1) at centre-of-mass energies of 7, 8 and 13 TeV. The CKM angle gamma is determined to be (69(-14)(+13))degrees using the measured CP-violating observables. The hadronic parameters r(B)(D)*(K +/-),r(B)(D)*(pi +/-),delta(D)(B)*(K +/-),delta(D)(B)*(pi +/-), which are the ratios and strong phase differences between favoured and suppressed B-+/- decays, are also reported.

A model-independent determination of the CKM angle gamma is presented, using the B-+/- -> [K+K-pi(+)pi(-)](D)h(+/-) and B-+/- -> [pi(+)pi(-)pi(+)pi(-)](D)h(+/-) decays, with h = K, pi. This measurement is the first phase-space binned study of these decay modes, and uses a sample of proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb(-1). The phase-space bins are optimised for sensitivity to gamma, and in each bin external inputs from the BESIII experiment are used to constrain the charm strong-phase parameters. The result of this binned analysis is gamma=(53.9(-8.9)(+9.5))degrees, where the uncertainty includes both statistical and systematic contributions. Furthermore, when combining with existing phase-space integrated measurements of the same decay modes, a value of gamma=(52.6(-6.4)(+8.5))degrees is obtained, which is one of the most precise determinations of gamma to date.

A search for the decay B-0 -> phi phi is made using pp collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13TeV, corresponding to an integrated luminosity of 9 fb(-1). No significant signal is observed, and an upper limit on the branching fraction of 1.3 (1.4) x 10(-8) at 90 (95)% confidence level is set. This result supersedes the previous LHCb study and improves the upper limit by a factor of two.

A study of charm mixing and CP violation in D0 → K±π∓π±π∓ decays isperformed using data collected by the LHCb experiment in proton-proton collisions from 2015to 2018, corresponding to an integrated luminosity of 6 fb−1. The ratio of promptly producedD0 → K+π−π+π− to D0 → K−π+π−π+ decay rates is measured as a function of D0 decaytime, both inclusive over phase space and in bins of phase space. Taking external inputsfor the D0- ¯D0 mixing parameters x and y allows constraints to be obtained on the hadronicparameters of the charm decay. When combined with previous measurements from charm-threshold experiments and at LHCb, improved knowledge is obtained for these parameters,which is valuable for studies of the angle γ of the Unitarity Triangle. An alternative analysisis also performed, in which external inputs are taken for the hadronic parameters, and themixing parameters are determined, including ∆x and ∆y, which are nonzero in the presence ofCP violation. It is found that x =(0.85+0.15−0.24)%, y =(0.21+0.29−0.27)%, ∆x = (−0.02 ± 0.04) %and ∆y =(0.02+0.04−0.03)%. These results are consistent with previous measurements and thehypothesis of CP conservation.

A first search at LHCb for the lepton-flavour-violating decays B-0 -> K*(0)tau(+/-)e(-/+) is presented. The analysis is performed using a sample of proton-proton collision data, collected with the LHCb detector at a centre-of-mass energy of 13TeV between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb(-1). No significant signal is observed, and upper limits on the branching fractions are determined to be B(B-0 -> K*(0)tau(-)e(+)) < 5.9 (7.1) x 10(-6) and B(B-0 -> K*(0)tau(+)e(-)) < 4.9 (5.9) x 10(-6) at the 90% (95%) confidence level. These results correspond to the current most stringent upper limits for b -> s tau l transitions.

An analysis of the flavour oscillations of the charmed neutral meson is presented. The ratio of D 0 → K + π − and D 0 → K − π + decay rates is measured as a function of the decay time of the D 0 meson and compared with the charge-conjugated system to search for charge-parity violation. The meson flavour at production is double-tagged by the charges of the muon and pion in the preceding B‾ → D* (2010) + π‾X and D ∗ (2010) +  →  D 0 π + decays, respectively. These decays are selected from proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 5.4 fb − 1 . The flavour oscillation parameters, relating to the differences in mass and width of the mass eigenstates, are found to be y ′ = (5.8 ± 1.6) × 10 − 3 and ( x ′) 2 = (0.0 ± 1.2) × 10 − 4 . No evidence for charge-parity violation is seen either in the flavour oscillations or in the decay, where the direct charge-parity asymmetry is measured to be A D = (2.3 ± 1.7) %.

A measurement of CP-violating observables associated with the interference of B 0 → D 0 K*(892) 0 and B 0 → D 0 (over bar)K*(892) 0 decay amplitudes is performed in the D 0 → K ± π ± (π + π - ), D 0 → π + π - (π + π - ), and D 0 → K + K - final states using data collected by the LHCb experiment corresponding to an integrated luminosity of 9 fb -1 . CP-violating observables related to the interference of B 0 s → D 0 K*(over bar)(892) 0 and B 0 s → D 0 (over bar)K*(over bar)(892) 0 are also measured, but no evidence for interference is found. The B 0 observables are used to constrain the parameter space of the CKM angle γ and the hadronic parameters r DK* B 0 and δ DK* B 0 with inputs from other measurements. In a combined analysis, these measurements allow for four solutions in the parameter space, only one of which is consistent with the world average.

A search for the decay B-0 -> phi mu(+) mu(-) is performed using proton-proton collisions at centre-of-mass energies of 7, 8, and 13 TeV collected by the LHCb experiment and corresponding to an integrated luminosity of 9 fb(-1). No evidence for the B-0 -> phi mu(+) mu(-) decay is found and an upper limit on the branching fraction, excluding the 0 and charmonium regions in the dimuon spectrum, of 4.4 x 10(-3) at a 90% credibility level, relative to that of the B-s(0) -> phi mu(+) mu(-) decay, is established. Using the measured B-s(0) -> phi mu(+) mu(-) branching fraction and assuming a phase-space model, the absolute branching fraction of the decay B-0 -> phi mu(+) mu(-) in the full q(2) range is determined to be less than 3.2 x 10(-9) at a 90% credibility level.

Abstract A first search forCPCP violation in the Cabibbo-suppressed\\varXi ⁺_(c) → p K ⁻ π ⁺ Ξ c + → p K - π + decay is performed using both a binned and an unbinned model-independent technique in the Dalitz plot. The studies are based on a sample of proton-proton collision data, corresponding to an integrated luminosity of3.0 \\text fb ⁻¹ 3.0 fb - 1 , and collected by the LHCb experiment at centre-of-mass energies of 7 and8 \\text TeV 8 TeV . The data are consistent with the hypothesis of noCPCP violation.