LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2019). A search for Xi(++)(cc) -> D(+)pK(-)pi(+) decays. J. High Energy Phys., 10(10), 124–21pp.
Abstract: A search for the Xi(++)(cc) baryon through the Xi(++)(cc) -> D(+)pK(-)pi(+) decay is performed with a data sample corresponding to an integrated luminosity of 1.7 fb(-1) recorded by the LHCb experiment in pp collisions at a centre-of-mass energy of 13 TeV. No significant signal is observed in the mass range from the kinematic threshold of the decay to 3800 MeV/c(2). An upper limit is set on the ratio of branching fractions R = B(Xi(++)(cc) -> D(+)pK(-)pi(+))/B(Xi(++)(cc) -> A(c)(+) K- pi(+)pi(+)) with R < 1.7 (2.1) x 10(-2) at the 90% (95%) confidence level at the known mass of the Xi(++)(cc) state.
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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). Amplitude analysis of B-s(0) -> K-S(0) K-+/-pi(-/+) decays. J. High Energy Phys., 06(6), 114–28pp.
Abstract: The first untagged decay-time-integrated amplitude analysis of B 0 s ! K 0 S K decays is performed using a sample corresponding to 3: 0 fb of pp collision data recorded with the LHCb detector during 2011 and 2012. The data are described with an amplitude model that contains contributions from the intermediate resonances K 9892) 0;+, K 2 91430) 0;+ and K 0 91430) 0;+, and their charge conjugates. Measurements of the branching fractions of the decay modes B 0 s ! K 9892) K and B 0 s ! K 9892) 0 K 0 are in agreement with, and more precise than, previous results. The decays B 0 s ! K 0 91430) K and B 0 s ! K 0 91430) 0 K 0 are observed for the fi rst time, each with signi fi cance over 10 standard deviations.
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LHCb Collaboration(Aaij, R. et al), Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2021). Angular analysis of B0 -> D*- D*s+ with D*s+ -> Ds + gamma decays. J. High Energy Phys., 06(6), 177–30pp.
Abstract: The first full angular analysis of the B0 -> D-Ds+ decay is performed using 6 fb(-1) of pp collision data collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The Ds+-> Ds+gamma and D*- -> D<overbar></mml:mover>0- vector meson decays are used with the subsequent Ds+ -> K+K-pi (+) and D<overbar></mml:mover>0 -> K+pi (-) decays. All helicity amplitudes and phases are measured, and the longitudinal polarisation fraction is determined to be f(L) = 0.578 +/- 0.010 +/- 0.011 with world-best precision, where the first uncertainty is statistical and the second is systematic. The pattern of helicity amplitude magnitudes is found to align with expectations from quark-helicity conservation in B decays. The ratio of branching fractions [B(B0 -> D-Ds+) x B(Ds+-> Ds+gamma)]/B(B-0 -> D(*-)Ds+) is measured to be 2.045 +/- 0.022 +/- 0.071 with world-best precision. In addition, the first observation of the Cabibbo-suppressed B-s -> D(*-)Ds+ decay is made with a significance of seven standard deviations. The branching fraction ratio B(B-s -> D(*-)Ds<mml:mo>+)/B(B-0 -> D(*-)Ds<mml:mo>+) is measured to be 0.049 +/- 0.006 +/- 0.003 +/- 0.002, where the third uncertainty is due to limited knowledge of the ratio of fragmentation fractions.<fig id=“Figa” position=“anchor”><graphic position=“anchor” specific-use=“HTML” mime-subtype=“JPEG” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“MediaObjects/13130202116089FigaHTML.jpg” id=“MO1”></graphic
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2015). Determination of the branching fractions of B-s(0) -> D-s(-/+) K-/+ and B-0 -> Ds-K+. J. High Energy Phys., 05(5), 019–16pp.
Abstract: Measurements are presented of the branching fractions of the decays B-s(0) -> D-s(-/+) K--/+ and B-0 -> Ds-K+ relative to the decays B-s(0) -> D-s(-)pi(+) and B-0 -> D-s(-)pi(+), respectively. The data used correspond to an integrated luminosity of 3.0 fb(-1) of proton-proton collisions. The ratios of branching fractions are B(B-s(0) -> D-s(-/+) K--/+)/B(B-s(0) -> D-s(-)pi(+)) = 0.0752 +/- 0.0015 +/- 0.0019 and B(B-0 -> Ds-K+)/B(B-0 -> D-pi(+)) = 0.0129 +/- 0.0005 +/- 0.0008, where the uncertainties are statistical and systematic, respectively.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2015). Differential branching fraction and angular analysis of Lambda(0)(b) -> Lambda mu(+)mu(-) decays. J. High Energy Phys., 06(6), 115–29pp.
Abstract: The differential branching fraction of the rare decay Lambda(0)(b) -> Lambda mu(+)mu(-) is measured as a function of q(2), the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), collected by the LHCb experiment. Evidence of signal is observed in the q(2) region below the square of the J/psi mass. Integrating over 15 < q(2) < 20 GeV2/c(4) the differential branching fraction is measured as dB(Lambda(0)(b) -> Lambda mu(+)mu(-))/dq(2) = (1.18(-0.08)(+0.09) +/- 0.03 +/- 0.27) x 10(-7) (GeV2/c(4))(-1) where the uncertainties are statistical, systematic and due to the normalisation mode Lambda(0)(b) -> J/psi Lambda , respectively. In the q(2) intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon (A(FB)(l)) and hadron (A(FB)(h)) systems are measured for the first time. In the range 15 < q(2) < 20GeV(2)/c(4) they are found to be A(FB)(l) = -0.05 +/- 0.09 (stat) +/- 0.03 (syst) and A(FB)(h) = -0.29 +/- 0.07 (stat) +/- 0.03 (syst).
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