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Bonilla, C., Lamprea, J. M., Peinado, E., & Valle, J. W. F. (2018). Flavour-symmetric type-II Dirac neutrino seesaw mechanism. Phys. Lett. B, 779, 257–261.
Abstract: We propose a Standard Model extension with underlying A(4) flavour symmetry where small Dirac neutrino masses arise from a Type-II seesaw mechanism. The model predicts the “golden” flavour-dependent bottom-tau mass relation, requires an inverted neutrino mass ordering and non-maximal atmospheric mixing angle. Using the latest neutrino oscillation global fit[ 1] we derive restrictions on the oscillation parameters, such as a correlation between delta(CP) and m(nu lightest).
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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), Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., & Ruiz Vidal, J. (2023). Measurement of CP asymmetries in D-(s)(+) -> eta pi(+) and D-(s)(+) -> eta 'pi(+) decays. J. High Energy Phys., 04(4), 081–23pp.
Abstract: Searches for CP violation in the decays D-(s)(+) -> eta pi(+) and D-(s)(+) -> eta'pi(+) are performed using pp collision data corresponding to 6 fb(-1) of integrated luminosity collected by the LHCb experiment. The calibration channels D-(s)(+) -> phi pi(+) are used to remove production and detection asymmetries. The resulting CP-violating asymmetries are A(CP) (D+ -> eta pi(+)) = (0.34 +/- 0.66 +/- 0.16 +/- 0.05)%, A(CP) (D-s(+) -> eta pi(+)) = (0.32 +/- 0.51 +/- 0.12)%, A(CP) (D+ -> eta'pi(+)) = (0.49 +/- 0.18 +/- 0.06 +/- 0.05)%, A(CP) (D-s(+) -> eta'pi(+)) = (0.01 +/- 0.12 +/- 0.08)%, where the first uncertainty is statistical, the second is systematic and the third, relevant for the D+ channels, is due to the uncertainty on A(CP) (D+ -> phi pi(+)). These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of CP violation. A combination of these results with previous LHCb measurements is presented.
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ATLAS Collaboration(Aad, G. et al), Cabrera Urban, S., Castillo Gimenez, V., Costa, M. J., Ferrer, A., Fiorini, L., et al. (2012). Measurement of the b-hadron production cross section using decays to D*(+)mu X- final states in pp collisions at root s=7 TeV with the ATLAS detector. Nucl. Phys. B, 864(3), 341–381.
Abstract: The b-hadron production cross section is measured with the ATLAS detector in pp collisions at root s = 7 TeV, using 3.3 pb(-1) of integrated luminosity, collected during the 2010 LHC run. The b-hadrons are selected by partially reconstructing D*(+)mu X- final states. Differential cross sections are measured as functions of the transverse momentum and pseudorapidity. The measured production cross section for a b-hadron with p(T) > 9 GeV and vertical bar eta vertical bar < 2.5 is 32.7 +/- 0.8(stat.)(-6.8)(+4.5)(syst.) μb, higher than the next-to-leading-order QCD predictions but consistent within the experimental and theoretical uncertainties.
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LHCb Collaboration(Aaij, R. et al), Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., & Ruiz Vidal, J. (2022). Measurement of the lifetimes of promptly produced Omega(0)(c) and Xi(9)(c) baryons. Sci. Bull., 67(5), 479–487.
Abstract: A measurement of the lifetimes of the Omega(0)(c) and Xi(0)(c) baryons is reported using proton-proton collision data at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb(-1) collected by the LHCb experiment. The Omega(0)(c) and Xi(0)(c) baryons are produced directly from proton interactions and reconstructed in the pK(-)K(-)pi(+) final state. The Omega(0)(c) lifetime is measured to be 276.5 +/- 13.4 +/- 4.4 +/- 0.7 fs, and the Xi(0)(c) lifetime is measured to be 148.0 +/- 2.3 +/- 2.2 +/- 0.2 fs, where the first uncertainty is statistical, the second systematic, and the third due to the uncertainty on the D-0 lifetime. These results confirm previous LHCb measurements based on semileptonic beauty-hadron decays, which disagree with earlier results of a four times shorter Omega(c)0 lifetime, and provide the single most precise measurement of the Omega(0 )(c)lifetime.
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