Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
319
result(s) for
"V. Fernandez Albor"
Sort by:
Erratum to: Measurement of $$\\psi (2S)$$ ψ(2S) meson production in pp collisions at $$\\sqrt{s}=7\\,\\hbox {TeV}$$ s=7TeV
This erratum corrects measurements of the prompt and secondary (from-b).
Journal Article
Evidence for CP violation in \\(B^+\\to p \\overline p K^+\\) decays
Three-body \\(B^+\\to p \\overline p K^+\\) and \\(B^+\\to p \\overline p \\pi^+\\) decays are studied using a data sample corresponding to an integrated luminosity of 3.0 \\(fb^{-1}\\) collected by the LHCb experiment in proton-proton collisions at center-of-mass energies of \\(7\\) and \\(8\\) TeV. Evidence of CP violation in the \\(B^+\\to p \\overline p K^+\\) decay is found in regions of the phase space, representing the first measurement of this kind for a final state containing baryons. Measurements of the forward-backward asymmetry of the light meson in the \\(p\\overline p\\) rest frame yield \\(A_{\\mathrm{FB}}(p \\overline p K^+,~m_{p\\overline p}<2.85\\mathrm{\\,Ge\\kern -0.1em V\\!/}c^2)=0.495\\pm0.012~(\\mathrm{stat})\\pm0.007~(\\mathrm{syst})\\) and \\(A_{\\mathrm{FB}}(p\\overline p \\pi^+,~m_{p\\overline p}<2.85\\mathrm{\\,Ge\\kern -0.1em V\\!/}c^2)=-0.409\\pm0.033~(\\mathrm{stat})\\pm0.006~(\\mathrm{syst})\\). In addition, the branching fraction of the decay \\(B^+\\to\\kern 0.1em\\overline{\\kern -0.1em\\Lambda}(1520)p\\) is measured to be \\(\\mathcal{B}(B^+ \\to \\kern 0.1em\\overline{\\kern -0.1em\\Lambda}(1520)p)=(3.15\\pm0.48~(\\mathrm{stat})\\pm0.07~(\\mathrm{syst})\\pm0.26~(\\mathrm{BF}))\\times 10^{-7}\\), where BF denotes the uncertainty on secondary branching fractions.
Paper
Measurement of psi(2S) meson production in pp collisions at sqrt(s)=7 TeV
The differential cross-section for the inclusive production of psi(2S) mesons in pp collisions at sqrt(s)=7 TeV has been measured with the LHCb detector. The data sample corresponds to an integrated luminosity of 36 pb-1. The psi(2S) mesons are reconstructed in the decay channels psi(2S) -> mu+ mu- and psi(2S) -> J/psi pi+ pi-, with the J/psi meson decaying into two muons. Results are presented both for promptly produced psi(2S) mesons and for those originating from b-hadron decays. In the kinematic range pT(psi(2S)) <= 16 GeV/c and 2 < y(psi(2S)) <= 4.5 we measure 1.44 +- 0.01 +- 0.12+0.2-0.4 mub for prompt psi(2S) production and 0.25 +- 0.01 +- 0.02 mub for psi(2S) from b-hadron decays, where the last uncertainty on the prompt cross-section is due to the unknown psi(2S) polarization. Recent QCD calculations are found to be in good agreement with our measurements. Combining the present result with the LHCb J/psi measurements we determine the inclusive branching fraction B(b -> psi(2S) X) = (2.73 +- 0.06 +- 0.16 +- 0.24) x 10^(-3), where the last uncertainty is due to the B(b -> J/psi X), B(J/psi -> mu+ mu-) and B(psi(2S) -> e+ e-) branching fraction uncertainties. All above results are corrected by an erratum included as an appendix.
Paper
Measurement of the relative rate of prompt \\(\\chi_{c0}\\), \\(\\chi_{c1}\\) and \\(\\chi_{c2}\\) production at \\(\\sqrt{s}=7\\)TeV
Prompt production of charmonium \\(\\chi_{c0}\\), \\(\\chi_{c1}\\) and \\(\\chi_{c2}\\) mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of \\(\\sqrt{s}=7\\)TeV. The \\(\\chi_{c}\\) mesons are identified through their decay to \\(J/\\psi\\gamma\\), with \\(J/\\psi\\to\\mu^+\\mu^-\\) using photons that converted in the detector. A data sample, corresponding to an integrated luminosity of \\(1.0\\mathrm{fb}^{-1}\\) collected by the LHCb detector, is used to measure the relative prompt production rate of \\(\\chi_{c1}\\) and \\(\\chi_{c2}\\) in the rapidity range \\(2.0
Paper
Observation of the \\(\\Lambda_b^0\\to\\Lambda\\phi\\) decay
The \\(\\Lambda_b^0\\to\\Lambda\\phi\\) decay is observed using data corresponding to an integrated luminosity of 3.0fb\\(^{-1}\\) recorded by the LHCb experiment. The decay proceeds at leading order via a \\(b\\to s\\bar{s}s\\) loop transition and is therefore sensitive to the possible presence of particles beyond the Standard Model. A first observation is reported with a significance of \\(5.9\\) standard deviations. The value of the branching fraction is measured to be \\((5.18\\pm1.04\\pm0.35\\,^{+0.67}_{-0.62})\\times10^{-6}\\), where the first uncertainty is statistical, the second is systematic, and the third is related to external inputs. Triple-product asymmetries are measured to be consistent with zero.
Paper
Measurement of the CKM angle gamma from a combination of B->Dh analyses
A combination of three LHCb measurements of the CKM angle gamma is presented. The decays B->DK and B->Dpi are used, where D denotes an admixture of D0 and D0-bar mesons, decaying into K+K-, pi+pi-, K+-pi-+, K+-pi-+pi+-pi-+, KSpi+pi-, or KSK+K- final states. All measurements use a dataset corresponding to 1.0 fb-1 of integrated luminosity. Combining results from B->DK decays alone a best-fit value of gamma = 72.0 deg is found, and confidence intervals are set gamma in [56.4,86.7] deg at 68% CL, gamma in [42.6,99.6] deg at 95% CL. The best-fit value of gamma found from a combination of results from B->Dpi decays alone, is gamma = 18.9 deg, and the confidence intervals gamma in [7.4,99.2] deg or [167.9,176.4] deg at 68% CL, are set, without constraint at 95% CL. The combination of results from B->DK and B->Dpi decays gives a best-fit value of gamma = 72.6 deg and the confidence intervals gamma in [55.4,82.3] deg at 68% CL, gamma in [40.2,92.7] deg at 95% CL are set. All values are expressed modulo 180 deg, and are obtained taking into account the effect of D0-D0bar mixing.
Paper
Measurement of B meson production cross-sections in proton-proton collisions at sqrt(s)= 7 TeV
The production cross-sections of B mesons are measured in pp collisions at a centre-of-mass energy of 7 TeV, using data collected with the LHCb detector corresponding to a integrated luminosity of 0.36 fb-1. The B+, B0 and Bs0 mesons are reconstructed in the exclusive decays B+ -> J/psi K+, B0 -> J/psi K*0 and Bs0 -> J/psi phi, with J/psi -> mu+ mu-, K*0 -> K+ pi- and phi -> K+ K-. The differential cross-sections are measured as functions of B meson transverse momentum pT and rapidity y, in the range 0 < pT < 40 GeV/c and 2.0 < y < 4.5. The integrated cross-sections in the same pT and y ranges, including charge-conjugate states, are measured to be sigma(pp -> B+ + X) = 38.9 +- 0.3 (stat.) +- 2.5 (syst.) +- 1.3 (norm.) mub, sigma(pp -> B0 + X) = 38.1 +- 0.6 (stat.) +- 3.7 (syst.) +- 4.7 (norm.) mub, sigma(pp -> Bs0 + X) = 10.5 +- 0.2 (stat.) +- 0.8 (syst.) +- 1.0 (norm.) mub, where the third uncertainty arises from the pre-existing branching fraction measurements.
Paper
Measurement of the polarisation amplitudes in B0 -> J/psi K(892)0 decays
An analysis of the decay B0 -> J/psi K*(892)0 is presented using data, corresponding to an integrated luminosity of 1.0fb^-1, collected in pp collisions at a centre-of-mass energy of 7TeV with the LHCb detector. The polarisation amplitudes and the corresponding phases are measured to be |A_{\\parallel}|^2 = 0.227 +- 0.004 (stat.) +- 0.011 (syst.), |A_{\\perp}|^2 = 0.201 +- 0.004 (stat.) +- 0.008 (syst.), \\delta_{\\parallel} [rad] = -2.94 +- 0.02 (stat.) +- 0.03 (syst.), \\delta_{\\perp} [rad] = 2.94 +- 0.02 (stat.) +- 0.02 (syst.). Comparing B0 -> J/psi K*(892)0 and \\bar{B}0 -> J/psi \\bar{K}*(892)0 decays, no evidence for direct CP violation is found.
Paper
Production of J/psi and Upsilon mesons in pp collisions at sqrt(s) = 8 TeV
The production of J/psi and Upsilon mesons in pp collisions at sqrt(s) = 8 TeV is studied with the LHCb detector. The J/psi and Upsilon mesons are reconstructed in the mu+mu- decay mode and the signal yields are determined with a fit to the mu+mu- invariant mass distributions. The analysis is performed in the rapidity range 2.0
Paper
Search for CP violation in D+ -> phi pi+ and Ds+ -> Ks pi+ decays
A search for CP violation in D+ -> phi pi+ decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb^{-1} at a centre of mass energy of 7 TeV. The CP-violating asymmetry is measured to be (-0.04+/-0.14+/-0.14)% for candidates with K-K+ mass within 20 MeV/c^{2} of the phi meson mass. A search for a CP-violating asymmetry that varies across the phi mass region of the D+ -> K-K+pi+ Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the Ds+ -> Ks pi+ decay is measured to be (0.61+/-0.83+/-0.14)%.
Paper