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Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. url  doi
openurl 
  Title (up) Precision luminosity measurements at LHCb Type Journal Article
  Year 2014 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.  
  Volume 9 Issue Pages P12005 - 91pp  
  Keywords Pattern recognition, cluster finding, calibration and fitting methods; Instrumentation for particle accelerators and storage rings – high energy (linear accelerators, synchrotrons)  
  Abstract Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy root s. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for root s = 2.76, 7 and 8TeV (proton-proton collisions) and for root s(NN) = 5TeV (proton-lead collisions). Both the “van der Meer scan” and “beam-gas imaging” luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves significantly the consistency of the results. For proton-proton interactions at root s = 8TeV a relative precision of the luminosity calibration of 1.47% is obtained using van der Meer scans and 1.43% using beam-gas imaging, resulting in a combined precision of 1.12%. Applying the calibration to the full data set determines the luminosity with a precision of 1.16%. This represents the most precise luminosity measurement achieved so far at a bunched-beam hadron collider.  
  Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Hicheur, A.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.] CBPF, Rio De Janeiro, Brazil, Email: rosen.matev@cern.ch  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1748-0221 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000345859200021 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2030  
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. url  doi
openurl 
  Title (up) Precision Measurement of CP Violation in B-S(0) -> J/Psi K+K- Decays Type Journal Article
  Year 2015 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 114 Issue 4 Pages 041801 - 9pp  
  Keywords  
  Abstract The time-dependent CP asymmetry in B-S(0) -> J/Psi K+K- decays is measured using pp collision data, corresponding to an integrated luminosity of 3.0 fb(-1), collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. In a sample of 96 000 B-S(0) -> J/Psi K+K- decays, the CP-violating phase phi(s) is measured, as well as the decay widths GL and GH of the light and heavy mass eigenstates of the B-s(0)-(B) over bar (0)(s) system. The values obtained are phi(s) = -0.058 +/- 0.049 +/- 0.006 rad, Gamma(s) equivalent to (Gamma(L) + Gamma(H))/2 = 0.6603 +/- 0.0027 +/- 0.0015 ps(-1), and Delta Gamma(s) equivalent to Gamma(L)-Gamma(H) = 0.0805 +/- 0.0091 +/- 0.0032 ps(-1), where the first uncertainty is statistical and the second, systematic. These are the most precise single measurements of those quantities to date. A combined analysis with B-s(0) -> J/Psi pi(+)pi(-) decays gives phi(s) = -0.010 +/- 0.039 rad. All measurements are in agreement with the standard model predictions. For the first time, the phase phi(s) is measured independently for each polarization state of the K+K- system and shows no evidence for polarization dependence.  
  Address [Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.] 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 Series Issue Edition  
  ISSN 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000351270800002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2170  
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Jaimes Elles, S.J.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Rebollo De Miguel, M.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanderswood, I.; Zhuo, J. url  doi
openurl 
  Title (up) Precision Measurement of CP Violation in the Penguin-Mediated Decay B0s → φφ Type Journal Article
  Year 2023 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 131 Issue 17 Pages 171802 - 12pp  
  Keywords  
  Abstract A flavor-tagged time-dependent angular analysis of the decay B0s -> phi phi is performed using pp collision integrated luminosity of 6 fb-1. The CP-violating phase and direct CP-violation parameter are measured to s = -0.042 +/- 0.075 +/- 0.009 rad and l lambda l = 1.004 +/- 0.030 +/- 0.009, respectively, assuming the same values for all polarization states of the phi phi system. In these results, the first uncertainties are statistical and the second systematic. These parameters are also determined separately for each polarization state, showing no evidence for polarization dependence. The results are combined with previous LHCb measurements using pp collisions at center-of-mass energies of 7 and 8 TeV, yielding phi sss over bar s = -0.074 +/- 0.069 rad and l lambda l = 1.009 +/- 0.030. This is the most precise study of time-dependent CP violation in a penguindominated B meson decay. The results are consistent with CP symmetry and with the standard model predictions.  
  Address [Leite, J. Baptista de Souza; Bediaga, I. B.; Torres, M. Cruz; Da Graca, U. De Freitas Carneiro; Miranda, J. M. De; dos Reis, A. C.; Falcao, L. N.; Fantini, L.; Gomes, A.] Ctr Brasileiro Pesquisas Fis 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 Series Issue Edition  
  ISSN 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001102957700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5897  
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. url  doi
openurl 
  Title (up) Precision measurement of forward Z boson production in proton-proton collisions at root s=13 TeV Type Journal Article
  Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 026 - 57pp  
  Keywords Electroweak Interaction; Forward Physics; Hadron-Hadron Scattering; Particle and Resonance Production  
  Abstract A precision measurement of the Z boson production cross-section at root s = 13 TeV in the forward region is presented, using pp collision data collected by the LHCb detector, corresponding to an integrated luminosity of 5.1 fb(-1). The production cross-section is measured using Z -> mu(+)mu(-) events within the fiducial region defined as pseudorapidity 2.0 < eta < 4.5 and transverse momentum p(T) > 20 GeV/c for both muons and dimuon invariant mass 60 < M-mu μ< 120 GeV/c(2). The integrated cross-section is determined to be sigma(Z -> mu(+)mu(-)) = 196.4 +/- 0.2 +/- 1.6 +/- 3.9 pb, where the first uncertainty is statistical, the second is systematic, and the third is due to the luminosity determination. The measured results are in agreement with theoretical predictions within uncertainties.  
  Address [de Souza Leite, J. Baptista; Bediaga, I; Torres, M. Cruz; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil, Email: hang.yin@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 Series Issue Edition  
  ISSN 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000825333400003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5299  
Permanent link to this record
 

 
Author BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. url  doi
openurl 
  Title (up) Precision Measurement of the B -> Xs gamma Photon Energy Spectrum, Branching Fraction, and Direct CP Asymmetry ACP(B -> Xs+d gamma) Type Journal Article
  Year 2012 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 109 Issue 19 Pages 191801 - 8pp  
  Keywords  
  Abstract The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B --> X-s gamma plus B --> X-d gamma, is studied using a data sample of (382.8 +/- 4.2) x 10(6)Y(4S) --> B (B) over bar decays collected by the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B --> X-s gamma) = (3.21 +/- 0.33) x 10(-4) for E-gamma > 1.8 GeV and the direct CP asymmetry A(CP)(B --> Xs+d gamma) = 0.057 +/- 0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.  
  Address [Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS, IN2P3, Lab Annecy Le Vieux Phys Particules LAPP, F-74941 Annecy Le Vieux, France  
  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 Series Issue Edition  
  ISSN 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000310869600003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1259  
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C. url  doi
openurl 
  Title (up) Precision measurement of the B-c(+) meson mass Type Journal Article
  Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 123 - 21pp  
  Keywords B physics; Hadron-Hadron scattering (experiments); QCD; Spectroscopy  
  Abstract A precision measurement of the B-c(+) meson mass is performed using proton- proton collision data collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to a total integrated luminosity of 9.0 fb(-1). The B-c(+) mesons are reconstructed via the decays B-c(+)-> J/psi pi(+), B-c(+)-> J/psi pi(+)pi(-)pi(+), B-c(+)-> J/psi pp<overbar>pi(+), B-c(+)-> J/psi D-s(+), B-c(+)-> J/psi (DK+)-K-0 and B-c(+)-> B-s(0)pi(+). Combining the results of the individual decay channels, the B-c(+) mass is measured to be 6274.47 +/- 0.27 (stat) +/- 0.17 (syst) MeV/c(2). This is the most precise measurement of the B-c(+) mass to date. The difference between the B-c(+) and B-s(0) meson masses is measured to be 907.75 +/- 0.37 (stat) +/- 0.27 (syst) MeV/c(2).  
  Address [Baptista Leite, J.; Bediaga, I; Torres, M. Cruz; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil, Email: yanting.fan@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 Series Issue Edition  
  ISSN 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000553446200002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4482  
Permanent link to this record
 

 
Author BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P. url  doi
openurl 
  Title (up) Precision measurement of the e(+)e(-) -> K+K-(gamma) cross section with the initial-state radiation method at BABAR Type Journal Article
  Year 2013 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 88 Issue 3 Pages 032013 - 28pp  
  Keywords  
  Abstract A precise measurement of the cross section for the process e(+)e(-) -> K+K-(gamma) from threshold to an energy of 5 GeV is obtained with the initial-state radiation (ISR) method using 232 fb(-1) of data collected with the BABAR detector at e(+)e(-) center-of-mass energies near 10.6 GeV. The measurement uses the effective ISR luminosity determined from the e(+)e(-) -> mu(+)mu(-)(gamma)gamma(ISR) process with the same data set. The corresponding lowest-order contribution to the hadronic vacuum polarization term in the muon magnetic anomaly is found to be a(mu)(KK,LO) = (22.93 +/- 0.18(stat) +/- 0.22(syst)) x 10(-10). The charged kaon form factor is extracted and compared to previous results. Its magnitude at large energy significantly exceeds the asymptotic QCD prediction, while the measured slope is consistent with the prediction.  
  Address [Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, LAPP, CNRS, IN2P3, F-74941 Annecy Le Vieux, France  
  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 Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000323609500003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1563  
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Garcia Martin, L.M.; Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.; Sanchez Mayordomo, C. url  doi
openurl 
  Title (up) Precision measurement of the Lambda(+)(c), Xi(+)(c), and Xi(0)(c) baryon lifetimes Type Journal Article
  Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 100 Issue 3 Pages 032001 - 12pp  
  Keywords  
  Abstract We report measurements of the lifetimes of the Lambda(+)(c), Xi(+)(c) and Xi(0)(c) charm baryons using proton- proton collision data at center- of- mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0 fb(-1), collected by the LHCb experiment. The charm baryons are reconstructed through the decays Lambda(+)(c) -> pK(-)pi(+),. Xi(+)(c) -> pK(-) pi(+) and Xi(0)(c) -> pK(-) K- pi(+), and originate from semimuonic decays of beauty baryons. The lifetimes are measured relative to that of the D+ meson, and are determined to be tau Lambda(+)(c) = 203.5 +/- 1.0 +/- 1.3 +/- 1.4 fs; tau Xi(+)(c) = 456.8 +/- 3.5 +/- 2.9 +/- 3.1 fs; tau Xi(0)(c) = 154.5 +/- 1.7 +/- 1.6 +/- 1.0 fs; where the uncertainties are statistical, systematic, and due to the uncertainty in the D+ lifetime. The measurements are approximately 3- 4 times more precise than the current world average values. The. +c and Xi(+)(c) lifetimes are in agreement with previous measurements; however, the Xi(0)(c) baryon lifetime is approximately 3.3 standard deviations larger than the world average value.  
  Address [Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Soares Lavra, I; Tourinho Jadallah Aoude, R.] 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 Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000478996400001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4103  
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. url  doi
openurl 
  Title (up) Precision Measurement of the Mass and Lifetime of the Xi(-)(b) Baryon Type Journal Article
  Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 113 Issue 24 Pages 242002 - 9pp  
  Keywords  
  Abstract We report on measurements of the mass and lifetime of the Xi(-)(b) baryon using about 1800 Xi(-)(b) decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb experiment. The decays are reconstructed in the Xi(-)(b) -> Xi(0)(c)pi(-), Xi(0)(c) -> pK(-)K(-)pi(+) channel and the mass and lifetime are measured using the Lambda(0)(b) -> Lambda(+)(c)pi(-) mode as a reference. We measure M(Xi(-)(b)) – M(Lambda(0)(b)) = 178.36 +/- 0.46 +/- 0.16 MeV/c(2), (tau Xi(-)(b)/tau Lambda(0)(b)) = 1.089 +/- 0.026 +/- 0.011, where the uncertainties are statistical and systematic, respectively. These results lead to a factor of 2 better precision on the Xi(-)(b) mass and lifetime compared to previous best measurements, and are consistent with theoretical expectations.  
  Address [Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Hicheur, A.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, 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 Series Issue Edition  
  ISSN 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000346387700009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2050  
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. url  doi
openurl 
  Title (up) Precision Measurement of the Mass and Lifetime of the Xi(0)(b) Baryon Type Journal Article
  Year 2014 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.  
  Volume 113 Issue 3 Pages 032001 - 10pp  
  Keywords  
  Abstract Using a proton-proton collision data sample corresponding to an integrated luminosity of 3 fb(-1) collected by LHCb at center-of-mass energies of 7 and 8 TeV, about 3800 Xi(0)(b) -> Xi(+)(c)pi(-), Xi(+)(c) -> pK(-)pi(+) signal decays are reconstructed. From this sample, the first measurement of the Xi(0)(b) baryon lifetime is made, relative to that of the Lambda(0)(b) baryon. The mass differences M(Xi(0)(b)) – M(Lambda(0)(b)) and M(Xi(+)(c)) – M(Lambda(+)(c)) are also measured with precision more than 4 times better than the current world averages. The resulting values are tau(Xi b0)/tau(Lambda b0) = 1.006 +/- 0.018 +/- 0.010, M(Xi(0)(b)) – M(Lambda(0)(b)) = 172.44 +/- 0.39 +/- 0.17 MeV/c(2), M(Xi(+)(c)) – M(Lambda(+)(c)) = 181.51 +/- 0.14 +/- 0.10 MeV/c(2), where the first uncertainty is statistical and the second is systematic. The relative rate of Xi(0)(b) to Lambda(0)(b) baryon production is measured to be f(Xi b0) B(Xi(0)(b) -> Xi(+)(c)pi(-)) B(Xi(+)(c) -> pK(-)pi(+))/f(Lambda b0) B(Lambda(0)(b) -> Lambda(+)(c)pi(-)) B(Lambda(+)(c) -> pK(-)pi(+)) = (1.88 +/- 0.04 +/- 0.03) x 10(-2), where the first factor is the ratio of fragmentation fractions, b -> Xi(0)(b) relative to b -> Lambda(0)(b). Relative production rates as functions of transverse momentum and pseudorapidity are also presented.  
  Address [Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Hicheur, A.; Kucewicz, W.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.] 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 Series Issue Edition  
  ISSN 0031-9007 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000341260100003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1912  
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