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 the B+ -> K*(+)mu(+) mu(-) Decay. Phys. Rev. Lett., 126(16), 161802–11pp.
Abstract: We present an angular analysis of the B+ -> K*(+)(-> K-S(0)pi(+))mu(+) mu(-) decay using 9 fb(-1) of pp collision data collected with the LHCb experiment. For the first time, the full set of CP-averaged angular observables is measured in intervals of the dimuon invariant mass squared. Local deviations from standard model predictions are observed, similar to those in previous LHCb analyses of the isospin-partner B-0 -> K*(0)mu(+)mu(-) decay. The global tension is dependent on which effective couplings are considered and on the choice of theory nuisance parameters.
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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). Near-threshold DD spectroscopy and observation of a new charmonium state. J. High Energy Phys., 07(7), 035–23pp.
Abstract: Using proton-proton collision data, corresponding to an integrated luminosity of 9 fb, collected with the LHCb detector between 2011 and 2018, a new narrow charmonium state, the X(3842) resonance, is observed in the decay modes X(3842) ! D0 D 0 and X(3842) ! D+D. The mass and the natural width of this state are measured to be where the fi rst uncertainty is statistical and the second is systematic. The observed mass and narrow natural width suggest the interpretation of the new state as the unobserved spin-3 3 1 3 D 3 charmonium state. In addition, prompt hadroproduction of the (3770) and 2 (3930) states is observed for the fi rst time, and the parameters of these states are measured to be m (3770) = 3778 : 1 0 : 7 0 : 6MeV where the first uncertainty is statistical and the second is systematic.
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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). Study of B-c(+) decays to charmonia and three light hadrons. J. High Energy Phys., 01(1), 065–28pp.
Abstract: Using proton-proton collision data, corresponding to an integrated luminosity of 9 fb(-1) collected with the LHCb detector, seven decay modes of the B-C(+) meson into a J/psi or psi(2S) meson and three charged hadrons, kaons or pions, are studied. The decays B-C (+)-> (psi(2S) -> J/psi pi(+)pi(-))pi(+), B+C -> (psi(2S)pi(+)pi(-)pi(+), B+C -> J/psi K+pi(-)pi(+) and B+C -> J/K+K-K+ are observed for the first time, and evidence for the B-C (+)-> (psi(2S)K+K-pi(+), decay is found, where J/psi and psi(2S) mesons are reconstructed in their dimuon decay modes. The ratios of branching fractions between the different B-C(+) decays are reported as well as the fractions of the decays proceeding via intermediate resonances. The results largely support the factorisation approach used for a theoretical description of the studied decays.
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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., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., Ruiz Valls, P., et al. (2017). Observation of B-c(+) -> (DK+)-K-0 Decays. Phys. Rev. Lett., 118(11), 111803–9pp.
Abstract: Using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LHCb detector at center-of-mass energies of 7 and 8 TeV, the B-c(+) -> (DK+)-K-0 decay is observed with a statistical significance of 5.1 standard deviations. By normalizing to B-c(+) -> (D) over bar (0)pi(+) decays, a measurement of the branching fraction multiplied by the production rates for B-c(+) relative to B+ mesons in the LHCb acceptance is obtained, R-D0K = (f(c)/f(u)) x B(B-c(+) -> (DK+)-K-0) = (9.3(-2.5)(+2.8) +/- 0.6) x 10(-7), where the first uncertainty is statistical and the second is systematic. This decay is expected to proceed predominantly through weak annihilation and penguin amplitudes, and is the first B-c(+) decay of this nature to be observed.
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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 structure in the J/psi-pair mass spectrum. Sci. Bull., 65(23), 1983–1993.
Abstract: Using proton-proton collision data at centre-of-mass energies of root s = 7, 8 and 13 TeV recorded by the LHCb experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 9 fb(-1), the invariant mass spectrum of J/psi pairs is studied. A narrow structure around 6.9 GeV/c(2) matching the line-shape of a resonance and a broad structure just above twice the J/psi mass are observed. The deviation of the data from nonresonant J/psi-pair production is above five standard deviations in the mass region between 6.2 and 7.4 GeV/c(2), covering predicted masses of states composed of four charm quarks. The mass and natural width of the narrow X(6900) structure are measured assuming a Breit-Wigner lineshape.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2019). Measurement of the ratio of branching fractions of the decays0(2S) and arrange Lambda. J. High Energy Phys., 03(3), 126–16pp.
Abstract: Using pp collisions corresponding to 3 fb integrated luminosity, recorded by the LHCb experiment at centre- of- mass energies of 7 and 8 TeV, the ratio of branching fractions B (0b ! (2 S) ) =B (0b ! J= ) = 0 : 513 0 : 023 (stat) 0 : 016 (syst) 0 : 011 (B) is determined. The first uncertainty is statistical, the second is systematic and the third is due to the external branching fractions used.
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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 an Excited B-c(+) State. Phys. Rev. Lett., 122(23), 232001–10pp.
Abstract: Using pp collision data corresponding to an integrated luminosity of 8.5 fb(-1) recorded by the LHCb experiment at center-of-mass energies of root s = 7, 8, and 13 TeV, the observation of an excited B-c(+) state in the B-c(+)pi(+)pi(-) invariant-mass spectrum is reported. The observed peak has a mass of 6841.2 +/- 0.6(stat) +/- 0.1(syst) +/- 0.8(B-c(+)) MeV/c(2), where the last uncertainty is due to the limited knowledge of the B-c(+) mass. It is consistent with expectations of the B-c*(2(3)S(1))(+) state reconstructed without the low-energy photon from the B-c*(1(3)S(1))(+) -> B-c(+)gamma decay following B-c*(2(3)S(1))(+) -> B-c*(1(3)S(1))(+)pi(+)pi(-). A second state is seen with a global (local) statistical significance of 2.2 sigma (3.2 sigma) and a mass of 6872.1 +/- 1.3(stat) +/- 0.1(syst) +/- 0.8(B-c(+)) MeV/c(2), and is consistent with the B-c(2(1)S(0))(+) state. These mass measurements are the most precise to date.
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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). Observation of a New Excited D-s(+) Meson in B-0 -> D- D+ K+ pi(-) Decays. Phys. Rev. Lett., 126(12), 122002–11pp.
Abstract: Using pp collision data corresponding to an integrated luminosity of 5.4 fb(-1) collected with the LHCb detector at a center-of-mass energy of 13 TeV, the B-0 -> D- D+ K+ pi(-) decay is studied. A new excited D-s(+) meson is observed decaying into the D+K+pi(-) final state with large statistical significance. The pole mass and width, and the spin parity of the new state are measured with an amplitude analysis to be m(R) = 2591 +/- 6 +/- 7 MeV, Gamma(R) = 89 +/- 16 +/- 12 MeV, and J(P) = 0(-), where the first uncertainty is statistical and the second systematic. Fit fractions for all components in the amplitude analysis are also reported. The new resonance, denoted as D-s0(2590)(+), is a strong candidate to be the D-s(2(1)S(0))(+) state, the radial excitation of the pseudoscalar ground-state D-s(+) meson.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2017). Study of charmonium production in b-hadron decays and first evidence for the decay B-s(0) -> phi phi phi. Eur. Phys. J. C, 77(9), 609–18pp.
Abstract: Using decays to f-meson pairs, the inclusive production of charmonium states in b-hadron decays is studied with pp collision data corresponding to an integrated luminosity of 3.0 fb(-1), collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. Denoting by B-C = B(b -> CX) x B(C -> phi phi) the inclusive branching fraction of a b hadron to a charmonium state C that decays into a pair of phi mesons, ratios R-C2(C1) = B-C1/B-C2 are determined as R-eta c(1S)(chi c0) = 0.147 +/- 0.023 +/- 0.011, R-eta c(1S)(chi c1) = 0.073 +/- 0.016 +/- 0.006, R-eta c(1S)(chi c2) = 0.081 +/- 0.013 +/- 0.005, R-chi c0(chi c1) = 0.50 +/- 0.11 +/- 0.01, R-chi c0(chi c2) = 0.56 +/- 0.10 +/- 0.01 and R-eta c(1S)(eta c(2S)) = 0.040 +/- 0.011 +/- 0.004. Here and below the first uncertainties are statistical and the second systematic. Upper limits at 90% confidence level for the inclusive production of X(3872), X(3915) and.c2(2P) states are obtained as R-chi c1(X(3872)) < 0.34, R-chi c0(X(3915)) < 0.12 and R-chi c2(chi c2(2P)) < 0.16. Differential cross-sections as a function of transverse momentum are measured for the eta(c)(1S) and chi(c) states. The branching fraction of the decay B-s(0). phi phi phi is measured for the first time, B(B-s(0) -> phi phi phi) = (2.15 +/- 0.54 +/- 0.28 +/- 0.21 B) x10(-6). Here the third uncertainty is due to the branching fraction of the decay B-s(0) -> phi phi, which is used for normalization. No evidence for intermediate resonances is seen. A preferentially transverse phi polarization is observed. Themeasurements allow the determination of the ratio of the branching fractions for the eta(c)(1S) decays to ff and p (p) over bar as B(eta(c)(1S) -> phi phi)/B(eta(c)(1S) -> p (p) over bar) = 1.79 +/- 0.14 +/- 0.32.
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