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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. (2018). Measurement of Upsilon production in pp collisions at root s=13 TeV. J. High Energy Phys., 07(7), 134–27pp.
Abstract: The production cross-sections of Upsilon(1S), Upsilon(2S) and Upsilon(3S) mesons in proton-proton collisions at root s = 13 TeV are measured with a data sample corresponding to an integrated luminosity of 277 +/- 11 pb(-1) recorded by the LHCb experiment in 2015. The Upsilon mesons are reconstructed in the decay mode Upsilon -> mu(+)mu(-). The differential production cross-sections times the dimuon branching fractions are measured as a function of the Upsilon transverse momentum, p(T) , and rapidity, y, over the range 0 < p(T) < 30 GeV/c and 2.0 < y < 4.5. The ratios of the cross-sections with respect to the LHCb measurement at root s = 8 TeV are also determined. The measurements are compared with theoretical predictions based on NRQCD.
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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). Measurement of the Y(nS) polarizations in pp collisions at root s=7 and 8 TeV. J. High Energy Phys., 12(12), 110–60pp.
Abstract: The polarization of the (sic) (1S), (sic) (2S) and (sic) (3S) mesons, produced in pp collisions at centre-of-mass energies root s = 7 and 8TeV, is measured using data samples collected by the LHCb experiment, corresponding to integrated luminosities of 1 and 2 fb(-1), respectively. The measurements are performed in three polarization frames, using (sic) -> μμdecays in the kinematic region of the transverse momentum p(T)((sic)) < 30 GeV/c and rapidity 2.2 < y((sic)) < 4.5. No large polarization is observed.
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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. (2018). Measurement of the time-integrated CP asymmetry in D (0) -> K (S) (0) K (S) (0) decays. J. High Energy Phys., 11(11), 048–19pp.
Abstract: A measurement of the time-integrated CP asymmetry in D (0) -> K (S) (0) K (S) (0) decays is reported. The data correspond to an integrated luminosity of about 2 fb(-1) collected in 2015-2016 by the LHCb collaboration in pp collisions at a centre-of-mass energy of 13 TeV. The D (0) candidate is required to originate from a D (*+) -> D (0) pi (+) decay, allowing the determination of the flavour of the D (0) meson using the pion charge. The D (0) -> K (+) K (-) decay, which has a well measured CP asymmetry, is used as a calibration channel. The CP asymmetryfor D (0) -> K (S) (0) K (S) (0) is measured to be where the first uncertainty is statistical and the second is systematic. This result is combined with the previous LHCb measurement at lower centre-of-mass energies to obtain A(CP) (D-0 -> K-S(0) K-S(0)) = (2.3 +/- 2.8 +/- 0.9)%.
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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). Measurement of the shape of the Lambda(0)(b) ->+ Lambda(+)(c) mu(-)(nu)over-bar μdifferential decay rate. Phys. Rev. D, 96(11), 112005–15pp.
Abstract: A measurement of the shape of the differential decay rate and the associated Isgur-Wise function for the decay Lambda(0)(b) ->+ Lambda(+)(c) mu(-) is reported, using data corresponding to 3 fb(-1) collected with the LHCb detector in proton-proton collisions. The Lambda(+)(c) mu(-)(nu) over bar μ(+anything) final states are reconstructed through the detection of a muon and Lambda(+)(c) baryon decaying into pK(-)pi(+), and the decay Lambda(0)(b) -> Lambda(+)(c)pi(+)pi(-)mu(-)(nu) over bar μare used to determine contributions from Lambda(0)(b) -> Lambda(c)*(+)mu(-)(nu) over bar μdecays. The measured dependence of the differential decay rate upon the squared four-momentum transfer between the heavy baryons, q(2), is compared with expectations from heavy-quark effective theory and from unquenched lattice QCD predictions.
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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). Measurement of the shape of the B-s(0) -> D-s*(-) mu(+) nu(mu) differential decay rate. J. High Energy Phys., 12(12), 144–32pp.
Abstract: The shape of the B-s(0) -> D-s*mu(+)nu(mu) differential decay rate is obtained as a function of the hadron recoil parameter using proton-proton collision data at a centreof-mass energy of 13TeV, corresponding to an integrated luminosity of 1.7 fb(-1) collected by the LHCb detector. The B-s(0) -> D-s*(-)mu(+)nu(mu) decay is reconstructed through the decays D-s*(-) up arrow D-s(-) gamma and D-s(-) -> K-K+pi(-). The differential decay rate is fitted with the CapriniLellouch-Neubert (CLN) and Boyd-Grinstein-Lebed (BGL) parametrisations of the form factors, and the relevant quantities for both are extracted.
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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). Measurement of the relative branching fractions of B+ -> h(+) h('+) h('-) decays. Phys. Rev. D, 102(11), 112010–19pp.
Abstract: The relative branching fractions of B+ -> h(+)h('+)h('-) decays, where h((')) is a pion or kaon, are measured. The analysis is performed with a data sample, collected with the LHCb detector, corresponding to an integrated luminosity of 3.0 fb(-1) of pp collisions. The results obtained improve significantly on previous measurements of these quantities, and are important for the interpretation of Dalitz plot analyses of three-body charmless hadronic decays of B+ mesons.
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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 relative B- -> D-0 / D*(0) / D**(0)mu(-)(nu)over-bar(mu) branching fractions using B- mesons from (B)over-bar(S)(2)*(0) decays. Phys. Rev. D, 99(9), 092009–16pp.
Abstract: The decay of the narrow resonance (B) over bar (s2)*(0 )-> B(-)K(+)can be used to determine the B- momentum in partially reconstructed decays without any assumptions on the decay products of the r meson. This technique is employed for the first time to distinguish contributions from D-0, D*(0), and higher-mass charmed states (D(0)) in semileptonic B- decays by using the missing-mass distribution. The measurement is performed using a data sample corresponding to an integrated luminosity of 3.0 fb(-1) collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8 TeV. The resulting branching fractions relative to the inclusive B- -> (DX)-X-0 mu(-)(nu) over bar (mu )are f(D)(0)= B(B- -> D-0 mu(-)(nu) over bar mu/B(B- ->(DX)-D- -X-0 mu(-)(nu) over bar (mu))( )= 0.25( )+/- 0.06, f( D)(0 )= B(B- -> (D(0) -> (DX)-X-0)mu(-)(nu) over bar (mu))/B(B--> (DX)-X-0 mu(-)(nu) over bar (mu)) = 0.21 +/- 0.07, with f(D)*(0) = 1 – f(D)(0) – f(D)(0) making up the remainder.
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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. (2018). Measurement of the Ratio of the B-0 -> D*(-)iota(+)v(iota) and B-0 -> D*(-) mu(+)v(mu) Branching Fractions Using Three-Prong tau-Lepton Decays. Phys. Rev. Lett., 120(17), 171802–11pp.
Abstract: The ratio of branching fractions R(D*(-)) equivalent to B(B-0 -> D*(-) iota(+)v(iota))/B(B-0 -> D*(-) mu+ v(mu)) is measured using a data sample of proton-proton collisions collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb(-1). For the first time, R(D*-) is determined using the iota-lepton decays with three charged pions in the final state. The B-0 -> D*(-) iota+ v(iota) yield is normalized to that of the B-0 -> D*(-) pi(+) pi(-) pi(+) mode, providing a measurement B-0 -> D*(-) iota+ v(iota) / B(B-0 -> D*(-) pi(+) pi(-) pi(+)) = 1.97 +/- 0.13 +/- 0.18, where the first uncertainty is statistical and the second systematic. The value of (B-0 -> D*(-) iota+ v(iota)) = (1.42 +/- 0.094 +/- 0.129 +/- 0.054)% is obtained, where the third uncertainty is due to the limited knowledge of the branching fraction of the normalization mode. Using the well-measured branching fraction of the B-0 -> D*(-) mu+ v(mu) decay, a value of R(D*(-)) = 0.291 +/- 0.019 +/- 0.026 +/- 0.013 is established, where the third uncertainty is due to the limited knowledge of the branching fractions of the normalization and B-0 -> D*(-) mu+ v(mu) modes. This measurement is in agreement with the standard model prediction and with previous results.
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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., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2018). Measurement of the Ratio of Branching Fractions B(B-c(+) -> J/psi tau(+)nu(tau))/B(B-c(+) -> J/psi mu(+)nu(mu)). Phys. Rev. Lett., 120(12), 121801–10pp.
Abstract: A measurement is reported of the ratio of branching fractions R(J/psi) = B(B-c(+) -> J/psi tau(+)nu(tau))/B(B-c(+) -> J/psi mu(+)nu(mu)), where the tau(+) lepton is identified in the decay mode tthorn tau(+) -> mu(+)nu(mu)(nu) over bar (tau). This analysis uses a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded with the LHCb experiment at center-of-mass energies of 7 and 8 TeV. A signal is found for the decay B-c(+) -> J/psi tau(+)nu(tau) at a significance of 3 standard deviations corrected for systematic uncertainty, and the ratio of the branching fractions is measured to be R(J/psi) = 0.71 +/- 0.17(stat) +/- 0.18(syst). This result lies within 2 standard deviations above the range of central values currently predicted by the standard model.
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