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Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C.
Title Measurement of Z -> tau(+)tau(-) production in proton-proton collisions at root s=8 TeV Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 159 - 19pp
Keywords Electroweak interaction; Forward physics; Hadron-Hadron scattering (experiments); Lepton production; Tau Physics
Abstract A measurement of Z -> tau(+)tau(-) production cross-section is presented using data, corresponding to an integrated luminosity of 2 fb(-1), from pp collisions at root s = 8 TeV collected by the LHCb experiment. The tau(+)tau(-)candidates are reconstructed in final states with the first tau lepton decaying leptonically, and the second decaying either leptonically or to one or three charged hadrons. The production cross-section is measured for Z bosons with invariant mass between 60 and 120 GeV/c(2), which decay to tau leptons with transverse momenta greater than 20 GeV/c and pseudorapidities between 2.0 and 4.5. The cross-section is determined to be sigma(pp -> Z -> tau+tau-)= 95.8 +/- 2.1 +/- 4.6 +/- 0.2 +/- 1.1 pb, where the first uncertainty is statistical, the second is systematic, the third is due to the LHC beam energy uncertainty, and the fourth to the integrated luminosity uncertainty. This result is compatible with NNLO Standard model predictions. The ratio of the cross-sections for Z -> tau(+)tau(- )to Z -> mu(+)mu(-) (Z -> e(+)e(-)), determined to be 1.01 +/- 0.05 (1.02 +/- 0.06), is consistent with the lepton-universality hypothesis in Z decays.
Address [Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; Gomes, A.; Massafferri, A.; Molina Rodriguez, J.; dos Reis, A. C.; Soares Lavra, L.; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: chitsanu.khurewathanakul@cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000446181600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3757
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Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C.
Title Angular moments of the decay Lambda(0)(b) -> Lambda mu(+)mu(-) at low hadronic recoil Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 146 - 27pp
Keywords B physics; FCNC Interaction; Flavor physics; Hadron-Hadron scattering (experiments); Rare decay
Abstract An analysis of the angular distribution of the decay Lambda(0)(b) -> Lambda mu(+)mu(-) is presented, using data collected with the LHCb detector between 2011 and 2016 and corresponding to an integrated luminosity of approximately 5 fb(-1). Angular observables are determined using a moment analysis of the angular distribution at low hadronic recoil, corresponding to the dimuon invariant mass squared range 15 < q(2) < 20 GeV2/c(4). The full basis of observables is measured for the first time. The lepton-side, hadron-side and combined forward-backward asymmetries of the decay are determined to be A(FB)(l) = -0.39 +/- 0.04 (stat) +/- 0.01 (syst), AFB(h) = -0.30 +/- 0.05 (stat) +/- 0.02 (syst), A(FB)(lh) = +0.25 +/- 0.04 (stat) +/- 0.01 (syst). The measurements are consistent with Standard Model predictions.
Address [Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; Gomes, A.; Massafferri, A.; Molina Rodriguez, J.; dos Reis, A. C.; Soares Lavra, L.; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: M.Kreps@warwick.ac.uk
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000446180700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3758
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C.
Title Search for a dimuon resonance in the Upsilon mass region Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 09 Issue 9 Pages 147 - 21pp
Keywords Beyond Standard Model; Hadron-Hadron scattering (experiments); Higgs physics
Abstract A search is performed for a spin-0 boson, phi, produced in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, using prompt phi -> mu(+)mu(-) decays and a data sample corresponding to an integrated luminosity of approximately 3.0 fb(-1) collected with the LHCb detector. No evidence is found for a signal in the mass range from 5.5 to 15 GeV. Upper limits are placed on the product of the production cross-section and the branching fraction into the dimuon final state. The limits are comparable to the best existing over most of the mass region considered and are the first to be set near the Upsilon resonances.
Address [Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; Gomes, A.; Massafferri, A.; Molina Rodriguez, J.; dos Reis, A. C.; Soares Lavra, L.; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: martino.borsato@cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000446180700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3759
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C.
Title First Observation of the Doubly Charmed Baryon Decay Xi(++)(cc) -> Xi(+)(c)pi(+) Type Journal Article
Year 2018 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 121 Issue 16 Pages 162002 - 10pp
Keywords
Abstract The doubly charmed baryon decay Xi(++)(cc) -> Xi(+)(c)pi(+) is observed for the first time, with a statistical significance of 5.9 sigma, confirming a recent observation of the baryon in the Lambda K-+(c)-pi(+)pi(+) final state. The data sample used corresponds to an integrated luminosity of 1.7 fb(-1), collected by the LHCb experiment in pp collisions at a center-of-mass energy of 13 TeV. The Xi(++)(cc) mass is measured to be 3620.6 +/- 1.5(stat) +/- 0.4(syst) +/- 0.3(Xi(+)(c)) MeV/c(2) and is consistent with the previous result. The ratio of branching fractions between the decay modes is measured to be [B(Xi(++)(cc) -> Xi(+)(c)pi(+)) x B(Xi(+)(c) -> pK(-)pi(+))]/[B(Xi(++)(cc) -> Lambda K-+(c)-pi(+)pi(+)) x B(Lambda(+)(c) -> pK(-)pi(+))] = 0.035 +/- 0.009 (stat) +/- 0.003 (syst).
Address [Bediaga, I.; Torres, M. Cruz; De Miranda, J. M.; Gomes, A.; Massafferri, A.; Molina Rodriguez, J.; Petruzzo, M.; dos Reis, A. C.; Soares Lavra, I.; Jadallah Aoude, R. Tourinho] CBPF, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000447486300010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3765
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Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C.
Title Search for beautiful tetraquarks in the Υ(1S)(+-) invariant-mass spectrum Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 086 - 22pp
Keywords B physics; Exotics; Hadron-Hadron scattering (experiments); Heavy quark production
Abstract The Υ(1 S) invariant-mass distribution is investigated for a possible exotic meson state composed of two b quarks and two b quarks, X bbbb. The analysis is based on a data sample of pp collisions recorded with the LHCb detector at centre-of-mass energies s = 7, 8 and 13 TeV, corresponding to an integrated luminosity of 6.3 fb. No signi fi cant excess is found, and upper limits are set on the product of the production cross-section and the branching fraction as functions of the mass of the X bbbb state. The limits are set in the fi ducial volume where all muons have pseudorapidity in the range [2 : 0; 5 : 0], and the X bbbb state has rapidity in the range [2 : 0; 4 : 5] and transverse momentum less than 15 GeV/c.
Address [Bediaga, I.; Cruz Torres, M.; De Miranda, J. M.; Gomes, A.; Massafferri, A.; Molina Rodriguez, J.; dos Reis, A. C.; Soares Lavra, L.; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: dcraik@cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000447516300002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3766
Permanent link to this record