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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). Study of the D(0)p amplitude in Lambda(0)(b) -> D(0)p pi(-) decays. J. High Energy Phys., 05(5), 030–43pp.
Abstract: An amplitude analysis of the decay Lambda(0)(b) -> D(0)p pi(-) is performed in the part of the phase space containing resonances in the D(0)p channel. The study is based on a data sample corresponding to an integrated luminosity of 3.0 fb(-1) of pp collisions recorded by the LHCb experiment. The spectrum of excited Lambda(+)(c) states that decay into D(0)p is studied. The masses, widths and quantum numbers of the Lambda(c)(2880)(+) and Lambda(c) (2940)(+) resonances are measured. The constraints on the spin and parity for the Lambda(c)(2940)(+) state are obtained for the first time. A near-threshold enhancement in the D(0)p amplitude is investigated and found to be consistent with a new resonance, denoted the Lambda(c) (2860)(+), of spin 3/2 and positive parity.
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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). Search for the B-s(0) -> eta'phi decay. J. High Energy Phys., 05(5), 158–18pp.
Abstract: A search for the charmless B-s(0) -> eta'phi decay is performed using pp collision data collected by the LHCb experiment at centre-of-mass energies of 7 and 8TeV, corresponding to an integrated luminosity of 3 fb(-1). No signal is observed and upper limits on the B-s(0) -> eta'phi branching fraction are set to 0.82 x 10(-6) at 90% and 1.01 x 10(-6) at 95% confidence level.
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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). Evidence for the two-body charmless baryonic decay B+ -> p(Lambda)over-bar. J. High Energy Phys., 04(4), 162–18pp.
Abstract: A search for the rare two-body charmless baryonic decay B+ -> p (Lambda) over bar is performed with pp collision data, corresponding to an integrated luminosity of 3 fb(-1), collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. An excess of B+ -> p (Lambda) over bar candidates with respect to background expectations is seen with a statistical significance of 4.1 standard deviations, and constitutes the first evidence for this decay. The branching fraction, measured using the B+ -> K-S(0)pi(+) decay for normalisation, is B(B+ -> p (Lambda) over bar) = (2.4(-0.8)(+)(+1.0) +/- 0.3) x 10(-7), where the first uncertainty is statistical and the second 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). Search for decays of neutral beauty mesons into four muons. J. High Energy Phys., 03(3), 001–19pp.
Abstract: A search for the non-resonant decays B-s(0) -> mu(+) mu(-) mu(+)mu(-) and B-0 -> mu(+) mu(-) mu(+) mu(-) is presented. The measurement is performed using the full Run 1 data set collected in proton-proton collisions by the LHCb experiment at the LHC. The data correspond to integrated luminosities of 1 and 2 fb(-1) collected at centre-of-mass energies of 7 and 8 TeV, respectively. No signal is observed and upper limits on the branching fractions of the non-resonant decays at 95% confidence level are determined to be B(B-s(0) -> mu(+) mu(-) mu(+)mu(-)) < 2.5 x 10(-9) B(B-0 -> mu(+) mu(-) mu(+) mu(-)) < 6.9 x 10(-10)
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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. (2016). Measurement of the CKM angle gamma from a combination of LHCb results. J. High Energy Phys., 12(12), 087–59pp.
Abstract: A combination of measurements sensitive to the CKM angle gamma from LHCb is performed. The inputs are from analyses of time-integrated B+ -> DK+, B-0 -> DK*(0), B-0 -> DK+ pi(-) and B+ -> DK+ pi(+) pi(-) tree-level decays. In addition, results from a time-dependent analysis of B-s(0) -> (DsK +/-)-K--/+ decays are included. The combination yields = (72: 2(-7.3)(+6:8) 7 : 3)degrees, where the uncertainty includes systematic effects. The 95.5% confidence level interval is determined to be gamma is an element of [55.9, 85.2]degrees. A second combination is investigated, also including measurements from B+ -> DK+, B-0 -> DK*(0), B-0 -> DK+ pi(-) and B+ -> DK+ pi(+) pi decays, which yields compatible results.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2017). Measurements of psi(2S) and X(3872) -> J/psi pi (+) pi (-) production in pp collisions at root s=8 Tev with the ATLAS detector. J. High Energy Phys., 01(1), 117–43pp.
Abstract: Differential cross sections are presented for the prompt and non-prompt production of the hidden-charm states X(3872) and psi(2S), in the decay mode J/psi pi (+) pi (-), measured using 11.4 fb(-1) of pp collisions at root s = 8 Tev by the ATLAS detector at the LHC. The ratio of cross-sections X(3872)/psi(2S) is also given, separately for prompt and non-prompt components, as well as the non-prompt fractions of X(3872) and psi(2S). Assuming independent single effective lifetimes for non-prompt X(3872) and psi(2S) production gives separating short- and long-lived contributions, assuming that the short-lived component is due to B (c) decays, gives R (B) = (3.57 +/- 0.33(stat) +/- 0.11(sys)) x 10(-2), with the fraction of non-prompt X(3872) produced via B (c) decays for p (T)(X(3872)) > 10 GeV being (25 +/- 13(stat) +/- 2(sys) +/- 5(spin))%. The distributions of the dipion invariant mass in the X(3872) and psi(2S) decays are also measured and compared to theoretical predictions.
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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. (2016). Differential branching fraction and angular moments analysis of the decay B-0 -> K+pi(-)mu(+)mu(-) in the K-0,K-2*(1431:)(0) region. J. High Energy Phys., 12(12), 065–24pp.
Abstract: Measurements of the differential branching fraction and angular moments of the decay B-0 -> K+pi(-)mu(+)mu(-) in the K+pi(-) invariant mass range 1330 <m(K+pi(-)) < 1530 MeV/c(2) are presented. Proton-proton collision data are used, corresponding to an integrated luminosity of 3 fb(-1) collected by the LHCb experiment. Differential branching fraction measurements are reported in five bins of the invariant mass squared of the dimuon system, q(2), between 0.1 and 8.0 GeV2/c(4). For the first time, an angular analysis sensitive to the S-, P- and D-wave contributions of this rare decay is performed. The set of 40 normalised angular moments describing the decay is presented for the q(2) range 1.1-6.0 GeV2/c(4).
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Measurements of the S-wave fraction in B-0 -> K+ pi(-) mu(+) mu(-) decays and the B-0 -> K*(892)(0) mu(+) mu(-) differential branching fraction. J. High Energy Phys., 11(11), 047–30pp.
Abstract: A measurement of the differential branching fraction of the decay B-0 -> K* (892)(0) mu(+)mu(-) is presented together with a determination of the S-wave fraction of the K+ pi(-) system in the decay B-0 -> K+ pi-mu(+)mu(-). The analysis is based on pp-collision data corresponding to an integrated luminosity of 3 fb(-1) collected with the LHCb experiment. The measurements are made in bins of the invariant mass squared of the dimuon system, q(2). Precise theoretical predictions for the differential branching fraction of B-0 -> K* (892)(0) mu(+) mu(-) decays are available for the q(2) region 1.1 < q(2) < 6.0 GeV2/c(4). In this q(2) region, for the K+pi(-) invariant mass range 796 < m(K pi) < 996MeV/c(2), the S-wave fraction of the K+pi(-) system in B-0 -> K+pi(-)mu(+)mu(-) decays is found to be F-S – 0.101 +/- 0.017(stat) +/- 0: 009(syst), and the differential branching fraction of B-0 -> K* (892)(0) mu(+)mu(-) decays is determined to be dB/dq(2) = (0.392(-0.019)(+ 0.020)(stat) +/- 0.010(syst) +/- 0.027(norm)) x 10(-7) c(4)/GeV2. The differential branching fraction measurements presented are the most precise to date and are found to be in agreement with Standard Model predictions.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2016). Measurement of the relative width difference of the B-0-(B)over-bar(0) system with the ATLAS detector. J. High Energy Phys., 06(6), 081–39pp.
Abstract: This paper presents the measurement of the relative width difference Delta Gamma(d)/Gamma(d) of the B-0-(B) over bar (0) system using the data collected by the Lambda TLAS experiment at the LHC in pp collisions at root s = 7 TeV and root s= 8 TeV and corresponding to an integrated luminosity of 25.2 fb(-1). The value of Delta Gamma(d)/Gamma(d) is obtained by comparing the decay-time distributions of B-0 -> J/Psi K-S and (B) over bar (0) -> J/Psi K*(0)(892) decays. The result is Delta Gamma(d)/Gamma(d) = (-0.1 +/- 1.1 (stat.) +/- 0.9 (syst.)) x 10(-2). Currently, this is the most precise single measurement of AFd/Fd. It agrees with the Standard Model prediction and the measurements by other experiments.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Measurement of the CKM angle gamma using B (0) -> DK (*0) with D -> K-S(0) pi (+) pi (-) decays. J. High Energy Phys., 08(8), 137–30pp.
Abstract: A model-dependent amplitude analysis of the decay B (0) -> D(K (S) (0) pi (+) pi (-))K (au 0) is performed using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb(-1), recorded at and 8 TeV by the LHCb experiment. The CP violation observables x (+/-) and y (+/-), sensitive to the CKM angle gamma, are measured to be x- = 0.15 +/- 0.14 +/- 0.03 +/- 0.01; y- = 0.25 +/- 0.15 +/- 0.06 +/- 0.01; x+ = 0.05 +/- 0.24 +/- 0.04 +/- 0.01; y+ = 0.65(-0.23)(+0.24) +/- 0.08 +/- 0.01; where the first uncertainties are statistical, the second systematic and the third arise from the uncertainty on the D -> K (S) (0) pi (+) pi (-) amplitude model. These are the most precise measurements of these observables. They correspond to gamma = (80 (- 22) (+ 21) )A degrees and , where is the magnitude of the ratio of the suppressed and favoured B (0) -> DK (+) pi (-) decay amplitudes, in a K pi mass region of +/- 50 MeV around the K (*)(892)(0) mass and for an absolute value of the cosine of the K (*0) decay angle larger than 0.4.
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