LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2023). Measurement of the Branching Fractions B(B0 → p(p)over-bar p(p)over-bar) and B(Bs0→ p(p)over-barp(p)over-bar). Phys. Rev. Lett., 131(9), 091901–11pp.
Abstract: Searches for the rare hadronic decays B-0 -> p (p) over barp (p) over bar and B-s(0) -> p (p) over barp (p) over bar are performed using proton-proton collision data recorded by the LHCb experiment and corresponding to an integrated luminosity of 9 fb-1. Significances of 9.3 sigma and 4.0 sigma, including statistical and systematic uncertainties, are obtained for the B-0 -> p (p) over barp (p) over bar and B-s(0) -> p (p) over barp (p) over bar signals, respectively. The branching fractions are measured relative to the topologically similar normalization decays B-0 -> J/psi(-> p (p) over bar )K*(0)(-> K+ pi(-) ) and B-s(0) -> J/psi(-> p (p) over bar )X phi(-> K+ K- ). The branching fractions are measured to be B(B-0 -> p (p) over barp (p) over bar) = (2.2 +/- 0.4 +/- 0.1 +/- 0.1) x 10(-8) and B(B-s(0) -> p (p) over barp (p) over bar) = (2.3 +/- 1.0 +/- 0.2 +/- 0.1) x 10(-8). In these measurements, the first uncertainty is statistical, the second is systematic, and the third one is due to the external branching fraction of the normalization channel.
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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2023). Search for the rare decays W+ → Ds+γ and Z → D0 γ at LHCb. Chin. Phys. C, 47(9), 093002–13pp.
Abstract: A search for the rare decays W+ -> D-s(+)gamma and Z -> D-0 gamma and is performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 2.0fb(-1). No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W+ -> mu(+)nu and Z ->mu(+)mu(-)decays as normalization channels. The upper limits are and at 95% confidence level for W+ -> D-s(+)gamma and Z -> D-0 gamma the and decay modes, respectively. This is the first reported search for Z -> D-0 gamma the decay, while the upper limit on the Z -> D-0 gamma branching fraction improves upon the previous best limit.
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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2023). Search for CP violation in the phase space of D0 → π-π+π0 decays with the energy test. J. High Energy Phys., 09(9), 129–24pp.
Abstract: A search for CP violation in D-0 -> pi(-)pi(+)pi(0) decays is reported, using pp collision data collected by the LHCb experiment from 2015 to 2018 corresponding to an integrated luminosity of 6 fb(-1). An unbinned model-independent approach provides sensitivity to local CP violation within the two-dimensional phase space of the decay. The method is validated using the Cabibbo-favoured channel D-0 -> K-pi(+)pi(0) and background regions of the signal mode. The results are consistent with CP symmetry in this decay.
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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2023). Measurement of CP asymmetries and branching fraction ratios of B- decays to two charm mesons. J. High Energy Phys., 09(9), 202–30pp.
Abstract: The CP asymmetries of seven B- decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb(-1) of proton-proton collisions collected by the LHCb experiment. Decays involving a D*(0) or D-s(*-) meson are analysed by reconstructing only the D-0 or D-s(-) decay products. This paper presents the first measurement of A(CP) (B- -> D-s(*-) D-0) and A(CP) (B- -> D-s(-) D*(0)), and the most precise measurement of the other five CP asymmetries. There is no evidence of CP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.
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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2023). Model-independent measurement of charm mixing parameters in Bbar → D0(→ K0Sπ+π-)μ-νbar_μX decays. Phys. Rev. D, 108(5), 052005–17pp.
Abstract: A measurement of charm mixing and CP-violating parameters is reported, using B over bar -> D0(-> K0S pi+pi-)x mu- nu over bar μX decays reconstructed in proton-proton collisions collected by the LHCb experiment during the years 2016 to 2018, corresponding to an integrated luminosity of 5.4 fb-1. The measured mixing and CP-violating parameters are xCP = [4.29 1 1.48(stat) 1 0.26(syst)] x 10-3, yCP = [12.61 1 3.12(stat) 1 0.83(syst)] x 10-3, Ax = [-0.77 1 0.93(stat) 1 0.28(syst)] x 10-3, Ay = [3.01 1 1.92(stat) 1 0.26(syst)] x 10-3. The results are complementary to and consistent with previous measurements. A combination with the recent LHCb analysis of D*+ -> D0(-> K0S pi+ pi-)pi+ decays is reported.
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