LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2019). Measurement of CP observables in the process B-0 -> DK*0 with two- and four-body D decays. J. High Energy Phys., 08(8), 041–30pp.
Abstract: Measurements of CP observables in B-0 -> DK0 decays are presented, where D represents a superposition of D-0 and D0 states. The D meson is reconstructed in the two-body final states K+pi(-), pi K-+(-), K+K- and pi(+)pi(-), and, for the first time, in the fourbody final states K+pi(-)pi(+)pi(-), pi K-+(-)pi(+)pi(-) and pi(+)pi(-)pi(+)pi(-). The analysis uses a sample of neutral B mesons produced in proton-proton collisions, corresponding to an integrated luminosity of 1.0, 2.0 and 1.8 fb(-1) collected with the LHCb detector at centre-of-mass energies of ,8 and 13 TeV, respectively. First observations of the decays B-0 -> D(pi K-+(-))K-0 and B-0 -> D(pi(+)pi(-)pi(+)pi(-))K-0 are obtained. The measured observables are interpreted in terms of the CP -violating weak phase gamma.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2019). Observation of the Lambda(0)(b) -> chi(c1) (3872)pK(-) decay. J. High Energy Phys., 09(9), 028–20pp.
Abstract: Using proton-proton collision data, collected with the LHCb detector and corresponding to 1.0, 2.0 and 1.9 fb(-1) of integrated luminosity at the centre-of-mass energies of 7, 8, and 13 TeV, respectively, the decay Lambda(0)(b) -> chi(c1)(3872)pK(-) with chi(c1)(3872) -> J/psi pi(+)pi(-) is observed for the first time. The significance of the observed signal is in excess of seven standard deviations. It is found that (58 +/- 15)% of the decays proceed via the two-body intermediate state chi(c1)(3872)Lambda(1520). The branching fraction with respect to that of the Lambda(0)(b) -> psi(2S)pK(-) decay mode, where the psi(2S) meson is reconstructed in the J/psi pi(+)pi(-) final state, is measured to be: B(Lambda(0)(b) -> chi(c1)(3872)pK(-))/B (Lambda(0)(b) -> psi(2S)pK(-)) x B(chi(c1)(3872) -> J/psi pi(+)pi(-))/B(psi(2S) -> J/psi pi(+)pi(-)) = (5.4 +/- 1.1 +/- 0.2) x 10(-2), where the first uncertainty is statistical and the second is systematic.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2020). Measurement of CP violation in B-0 -> (DD -/+)-D-*+/- decays. J. High Energy Phys., 03(3), 147–28pp.
Abstract: The decay-time-dependent CP asymmetry in B-0 -> (DD -/+)-D-*+/- decays is mea- sured using a data set corresponding to an integrated luminosity of 9 fb(-1) recorded by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The CP parameters are measured asSD*D=-0.861 +/- 0.077 +/- 0.019,Delta SD*D=0.019 +/- 0.075 +/- 0.012,CD*D=-0.059 +/- 0.092 +/- 0.020,Delta CD*D=-0.031 +/- 0.092 +/- 0.016,AD*D=0.008 +/- 0.014 +/- 0.006. The analysis provides the most precise single measurement of CP violation in this decay channel to date. All parameters are consistent with their current world average values.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2020). Observation of the semileptonic decay B+-> p(p)over-bar mu(+)nu(mu). J. High Energy Phys., 03(3), 146–22pp.
Abstract: The Cabibbo-suppressed semileptonic decay B+-> pp over bar mu+nu μis observed for the first time using a sample of pp collisions corresponding to an integrated luminosity of 1.0, 2.0 and 1.7 fb at centre-of-mass energies of 7, 8 and 13TeV, respectively. The differential branching fraction is measured as a function of the pp invariant mass using the decay mode B+ ! J= K+ for normalisation. The total branching fraction is measured to be B (B+ ! pp+) = (5:27+0:23 0:21 0:15) 10 where the first uncertainty is statistical, the second systematic and the third is from the uncertainty on the branching fraction of the normalisation channel.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2020). Test of lepton universality with Lambda(0)(b) -> pK(-) l(+)l(-). J. High Energy Phys., 05(5), 40–27pp.
Abstract: The ratio of branching fractions of the decays -> pK(-)mu(+)mu(-),RpK-1}, is measured for the first time using proton-proton collision data corresponding to an integrated luminosity of 4.7 fb(-1) recorded with the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV. In the dilepton mass-squared range 0.1 < q(2)< 6.0 GeV2/c(4) and the pK(-) mass range m(pK(-)) < 2600 MeV/c(2), the ratio of branching fractions is measured to be RpK-1=1.17-0.16+0.18 +/- 0.0$$ {R}{pK}<^>{-1}={1.17}{-0.16}<^>{+0.18}\pm 0.07 $$\end{document}, where the first uncertainty is statistical and the second systematic. This is the first test of lepton universality with b baryons and the first observation of the decay -> pK(-)e(+)e(-).
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