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Author LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.
Title Search for the rare decay B-0 -> J/psi phi Type Journal Article
Year 2021 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C
Volume 45 Issue 4 Pages 043001 - 14pp
Keywords B physics; flavour physics; rare decay; omega – phi mixing; branching fraction
Abstract A search for the rare decay B-0 -> J/psi phi, is performed using pp collision data collected with the LHCb detector at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb(-1). No significant signal of the decay is observed and an upper limit of 1.1 x 10(-7) at 90% confidence level is set on the branching fraction.
Address [Bediaga, I.; Cruz Torres, M.; De Miranda, J. M.; Gomes, A.; Massafferri, A.; dos Reis, A. C.; Soares Lavra, L.; Tourinho Jadallah Aoude, R.] CBPF, Rio De Janeiro, Brazil, Email: maria.vieites.diaz@cern.ch
Corporate Author Thesis
Publisher (up) 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 1674-1137 ISBN Medium
Area Expedition Conference
Notes WOS:000630745400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4751
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Author LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.
Title Search for the doubly heavy baryons Omega(0)(bc) and Xi(0)(bc) decaying to Lambda(+)(c)pi(-) and Xi(+)(c)pi- Type Journal Article
Year 2021 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C
Volume 45 Issue 9 Pages 093002 - 12pp
Keywords B physics; quarkonium; spectroscopy; heavy quark production
Abstract The first search for the doubly heavy Omega(0)(bc) baryon and a search for the Xi(0)(bc) baryon are performed using collision data collected via the experiment from 2016 to 2018 at a centre-of-mass energy of, corresponding to an integrated luminosity of 5.2 fb(-1). The baryons are reconstructed via their decays to Lambda(+)(-)(c)(pi) and Xi(+)(c)pi(-). No significant excess is found for invariant masses between 6700 and 7300 MeV/c(2), in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c. Upper limits are set on the ratio of the Omega(0)(bc) and Xi(0)(bc) production cross-section times the branching fraction to Lambda(+)(c)pi(-)(Xi(+)(c)pi(-)) relative to that of the Lambda(0)(b)(Xi(0)(b)) baryon, for different lifetime hypotheses, at 95% confidence level. The upper limits range from 0.5x10(-4) to 2.5x10(-4) for the Omega(0)(bc) -> Lambda(+)(c)pi(-) (Xi(0)(bc) -> Lambda(+)(c)pi(-)) decay, pending on the considered mass and lifetime of the Omega(0)(bc) (Xi(0)(bc)) baryon.
Address [Leite, J. Baptista; 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: shiyang.li@cern.ch
Corporate Author Thesis
Publisher (up) 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 1674-1137 ISBN Medium
Area Expedition Conference
Notes WOS:000693209400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4974
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Author LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.
Title Identification of charm jets at LHCb Type Journal Article
Year 2022 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 17 Issue 2 Pages P02028 - 23pp
Keywords Analysis and statistical methods; Pattern recognition; cluster finding; calibration and fitting methods; Performance of High Energy Physics Detectors
Abstract The identification of charm jets is achieved at LHCb for data collected in 2015-2018 using a method based on the properties of displaced vertices reconstructed and matched with jets. The performance of this method is determined using a dijet calibration dataset recorded by the LHCb detector and selected such that the jets are unbiased in quantities used in the tagging algorithm. The charm-tagging efficiency is reported as a function of the transverse momentum of the jet. The measured efficiencies are compared to those obtained from simulation and found to be in good agreement.
Address [Leite, J. Baptista; 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: dcraik@cern.ch
Corporate Author Thesis
Publisher (up) 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:000770368300015 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5177
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Author LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.
Title Centrality determination in heavy-ion collisions with the LHCb detector Type Journal Article
Year 2022 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 17 Issue 5 Pages P05009 - 31pp
Keywords Pattern recognition; cluster finding; calibration and fitting methods; Performance of High Energy Physics Detectors; Simulation methods and programs
Abstract The centrality of heavy-ion collisions is directly related to the created medium in these interactions. A procedure to determine the centrality of collisions with the LHCb detector is implemented for lead-lead collisions root s(NN) = 5 TeV and lead-neon fixed-target collisions at root s(NN) = 69 GeV. The energy deposits in the electromagnetic calorimeter are used to determine and define the centrality classes. The correspondence between the number of participants and the centrality for the lead-lead collisions is in good agreement with the correspondence found in other experiments, and the centrality measurements for the lead-neon collisions presented here are performed for the first time in fixed-target collisions at the LHC.
Address [Leite, J. Baptista; 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
Corporate Author Thesis
Publisher (up) 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:000832952600001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5315
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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.
Title Search for the doubly heavy baryon Ξbc+ decaying to J/ψΞc+ Type Journal Article
Year 2023 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C
Volume 47 Issue 9 Pages 093001 - 13pp
Keywords QCD; B physics; charm physics; spectroscopy
Abstract A first search for the Xi(+)(bc) -> J/psi Xi c+ decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb(-1) recorded at centre-of-mass energies of 7, 8, and 13 TeV. Two peaking structures are seen with a local (global) significance of and standard deviations at masses of 6571 and 6694 MeV/c(2), respectively. Upper limits are set on the Xi(+)(bc) baryon production cross-section times the branching fraction relative to that of the B-c(+) -> J/psi Xi(+)(c) decay at centre-of-mass energies of 8 and 13 TeV, in the Xi(+)(bc) and in the rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to, respectively. Upper limits are presented as a function of the Xi(+)(bc) mass and lifetime.
Address [Baptista De Souza Leite, J.; Bediaga, I. B.; Torres, M. Cruz; De Freitas Carneiro Da Graca, U.; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massafferri, A.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fisicas CBPF, Rio De Janeiro, Brazil
Corporate Author Thesis
Publisher (up) 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 1674-1137 ISBN Medium
Area Expedition Conference
Notes WOS:001062113700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5751
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.
Title Search for the rare decays W+ → Ds+γ and Z → D0 γ at LHCb Type Journal Article
Year 2023 Publication Chinese Physics C Abbreviated Journal Chin. Phys. C
Volume 47 Issue 9 Pages 093002 - 13pp
Keywords W/Z boson; rare decay; upper limit of branching fraction
Abstract A search for the rare decays W+ -> D-s(+)gamma and Z -> D-0 gamma and is performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 2.0fb(-1). No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W+ -> mu(+)nu and Z ->mu(+)mu(-)decays as normalization channels. The upper limits are and at 95% confidence level for W+ -> D-s(+)gamma and Z -> D-0 gamma the and decay modes, respectively. This is the first reported search for Z -> D-0 gamma the decay, while the upper limit on the Z -> D-0 gamma branching fraction improves upon the previous best limit.
Address [Baptista de Souza Leite, J.; Bediaga, I. B.; Cruz Torres, M.; De Freitas Carneiro Da Graca, U.; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massafferri, A.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: juan.baptista.leite@cern.ch
Corporate Author Thesis
Publisher (up) 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 1674-1137 ISBN Medium
Area Expedition Conference
Notes WOS:001062397200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5808
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.; Sanderswood, I.; Zhuo, J.
Title Curvature-bias corrections using a pseudomass method Type Journal Article
Year 2024 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 19 Issue 3 Pages P03010 - 22pp
Keywords Analysis and statistical methods; Detector alignment and calibration methods (lasers, sources, particle-beams); Large detector-systems performance; Performance of High Energy Physics Detectors
Abstract Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy root s = 13 TeV during 2016, 2017 and 2018. The biases are determined using Z -> mu(+)mu(-) decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10(-4) GeV-1 level, improves the Z -> mu(+)mu(-) mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass.
Address [Egede, U.; Fujii, Y.; Hadavizadeh, T.; Henderson, R. D. L.; Lane, J. J.; Monk, M.; Song, R.; Walton, E. J.; Ward, J. A.] Monash Univ, Sch Phys & Astron, Melbourne, Vic, Australia, Email: seophine.stanislaus@cern.ch
Corporate Author Thesis
Publisher (up) 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:001190907900003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6057
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.; Sanderswood, I.; Zhuo, J.
Title Helium identification with LHCb Type Journal Article
Year 2024 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 19 Issue 2 Pages P02010 - 23pp
Keywords dE/dx detectors; Ion identification systems; Large detector systems for particle and astroparticle physics; Particle identification methods
Abstract The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at root s = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb(-1). A total of around 10(5) helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10(12)). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei.
Address [Egede, U.; Fujii, Y.; Hadavizadeh, T.; Henderson, R. D. L.; Lane, J. J.; Monk, M.; Song, R.; Walton, E. J.; Ward, J. A.] Monash Univ, Sch Phys & Astron, Melbourne, Vic, Australia, Email: rmoise@cern.ch
Corporate Author Thesis
Publisher (up) 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:001185791500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6068
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.; Sanderswood, I.; Zhuo, J.
Title Momentum scale calibration of the LHCb spectrometer Type Journal Article
Year 2024 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 19 Issue 2 Pages P02008 - 21pp
Keywords Particle tracking detectors; Analysis and statistical methods
Abstract For accurate determination of particle masses accurate knowledge of the momentum scale of the detectors is crucial. The procedure used to calibrate the momentum scale of the LHCb spectrometer is described and illustrated using the performance obtained with an integrated luminosity of 1.6 fb-1 collected during 2016 in pp running. The procedure uses large samples of J/qi -> mu+mu- and B+ -> J/qiK+ decays and leads to a relative accuracy of 3 x 10-4 on the momentum scale.
Address [Egede, U.; Fujii, Y.; Hadavizadeh, T.; Henderson, R. D. L.; Lane, J. J.; Monk, M.; Song, R.; Walton, E. J.; Ward, J. A.] Monash Univ, Sch Phys & Astron, Melbourne, Vic, Australia, Email: seophine.stanislaus@cern.ch
Corporate Author Thesis
Publisher (up) 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:001185791500004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 6070
Permanent link to this record
 

 
Author LHCb Collaboration (Aaij, R. et al); Henry, L.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.
Title Precise determination of the B-s(0)-B-s(-0) oscillation frequency Type Journal Article
Year 2022 Publication Nature Physics Abbreviated Journal Nat. Phys.
Volume 18 Issue Pages 54-58
Keywords
Abstract Mesons comprising a beauty quark and strange quark can oscillate between particle (B-s(0)) and antiparticle (B-s(-0)) flavour eigenstates, with a frequency given by the mass difference between heavy and light mass eigenstates, Delta m(s). Here we present a measurement of Delta m(s) using B-s(0) -> D-s(-)pi(+) decays produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The oscillation frequency is found to be Delta m(s) = 17.7683 +/- 0.0051 +/- 0.0032 ps(-1), where the first uncertainty is statistical and the second is systematic. This measurement improves on the current Delta m(s) precision by a factor of two. We combine this result with previous LHCb measurements to determine Delta m(s) = 17.7656 +/- 0.0057 ps(-1), which is the legacy measurement of the original LHCb detector.
Address [Aaij, R.; Butter, J. S.; Akiba, K. Carvalho; Sole, S. Ferreres; Gabriel, E.; Geertsema, R. E.; Greeven, L. M.; Heijhoff, K.; Hulsbergen, W.; Hynds, D.; Jans, E.; Klaver, S.; Koppenburg, P.; Kostiuk, I; Kuindersma, H. S.; Martinez, M. Lucio; Lukashenko, V; Mauri, A.; Merk, M.; Pellegrino, A.; Sanchez Gras, C.; Schubiger, M.; Snoch, A.; Tuning, N.; Usachov, A.; van Beuzekom, M.; Veronesi, M.] Nikhef Natl Inst Subatom Phys, Amsterdam, Netherlands, Email: alessandro.bertolin@pd.infn.it
Corporate Author Thesis
Publisher (up) Nature Portfolio Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1745-2473 ISBN Medium
Area Expedition Conference
Notes WOS:000739810100002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5075
Permanent link to this record