Records |
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 |
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Thesis |
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Publisher |
IOP Publishing Ltd |
Place of Publication |
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English |
Summary Language |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1748-0221 |
ISBN |
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Conference |
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Notes ![sorted by Notes field, descending order (down)](img/sort_desc.gif) |
WOS:001190907900003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
6057 |
Permanent link to this record |
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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.; Ruiz Vidal, J.; Sanderswood, I.; Zhuo, J. |
Title |
Improved Measurement of CP Violation Parameters in B0s → J/ψ K+ K- Decays in the Vicinity of the φ(1020) Resonance |
Type |
Journal Article |
Year |
2024 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
132 |
Issue |
5 |
Pages |
051802 - 12pp |
Keywords |
|
Abstract |
The decay-time-dependent CP asymmetry in B0s -> J=psi(-> mu+mu-)K+K- decays is measured using proton-proton collision data, corresponding to an integrated luminosity of 6 fb-1, collected with the LHCb detector at a center-of-mass energy of 13 TeV. Using a sample of approximately 349 000 B0s signal decays with an invariant K+K- mass in the vicinity of the phi(1020) resonance, the CP-violating phase phi s is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the B0s-B over bar 0s system, Delta Gamma s, and the difference of the average B0s and B0 meson decay widths, Gamma s – Gamma d. The values obtained are phi s = -0.039 +/- 0.022 +/- 0.006 rad, Delta Gamma s = 0.0845 +/- 0.0044 +/- 0.0024 ps-1, and -0.0015 +/- 0.0014 ps-1, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements to date and are consistent with expectations based on the Standard Model and with the previous LHCb analyses of this decay. These results are combined with previous independent LHCb measurements. The phase phi s is also measured independently for each polarization state of the K+K- system and shows no evidence for polarization dependence. |
Address |
[Baptista de Souza Leite, J.; Bediaga, I. B.; Cruz Torres, M.; De Freitas Carneiro Da Graca, U.; De Miranda, J. M.; De Serio, M.; Debernardis, F.; dos Reis, A. C.; Falcao, L. N.; Galati, G.; Gomes, A.; Massafferri, A.; Pappagallo, M.; Santoro, L.; Simone, S.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fisicas CBPF, Rio De Janeiro, Brazil |
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Publisher |
Amer Physical Soc |
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English |
Summary Language |
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Original Title |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Notes ![sorted by Notes field, descending order (down)](img/sort_desc.gif) |
WOS:001190889800002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
6111 |
Permanent link to this record |
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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.; Ruiz Vidal, J.; Sanderswood, I. |
Title |
Observation of Cabibbo-Suppressed Two-Body Hadronic Decays and Precision Mass Measurement of the Ω0c Baryon |
Type |
Journal Article |
Year |
2024 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
132 |
Issue |
8 |
Pages |
081802 - 11pp |
Keywords |
|
Abstract |
The first observation of the singly Cabibbo-suppressed 0c -> -K thorn and 0c -> -z thorn decays is reported, using proton -proton collision data at a center -of -mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb-1, collected with the LHCb detector between 2016 and 2018. The branching fraction ratios are measured to be Bo0c ->-K thorn thorn Bo0c ->-z thorn thorn 1/4 1/26.08 ⠂ 0.51ostat thorn ⠂ 0.40osyst thorn ⠃%; Bo0c ->-z thorn thorn Bo0c ->-z thorn thorn 1/4 1/215.81 ⠂ 0.87ostat thorn ⠂ 0.44osyst thorn ⠂ 0.16oext thorn ⠃%. In addition, using the 0c -> -z thorn decay channel, the 0c baryon mass is measured to be Mo0c thorn 1/4 2695.28 ⠂ 0.07ostat thorn ⠂ 0.27osyst thorn ⠂ 0.30oext thorn MeV; improving the precision of the previous world average by a factor of 4. |
Address |
[Leite, J. Baptista de Souza; Bediaga, I. B.; Torres, M. Cruz; Da Graca, U. De Freitas Carneiro; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massafferri, A.; Santoro, L.; Machado, D. Torres] CBPF, Rio De Janeiro, Brazil |
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Amer Physical Soc |
Place of Publication |
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English |
Summary Language |
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Original Title |
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Series Editor |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes ![sorted by Notes field, descending order (down)](img/sort_desc.gif) |
WOS:001190704700002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
6053 |
Permanent link to this record |
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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.; Ruiz Vidal, J.; Sanderswood, I.; Zhuo, J. |
Title |
Measurement of prompt D+ and Ds+ production in pPb collisions at √s_NN=5.02 TeV |
Type |
Journal Article |
Year |
2024 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
01 |
Issue |
1 |
Pages |
070 - 43pp |
Keywords |
Heavy Quark Production; Relativistic Heavy Ion Physics; QCD; Heavy Ion Experiments |
Abstract |
The production of prompt D+ and D-s(+) mesons is studied in proton-lead collisions at a centre-of-mass energy of root s(NN) = 5.02TeV. The data sample corresponding to an integrated luminosity of (1.58 +/- 0.02)nb(-1) is collected by the LHCb experiment at the LHC. The differential production cross-sections are measured using D+ and D-s(+) candidates with transverse momentum in the range of 0 < p(T) < 14 GeV/c and rapidities in the ranges of 1.5 < y* < 4.0 and -5.0 < y* < -2.5 in the nucleon-nucleon centre-of-mass system. For both particles, the nuclear modification factor and the forward-backward production ratio are determined. These results are compared with theoretical models that include initial-state nuclear effects. In addition, measurements of the cross-section ratios between D+, D-s(+) and D-0 mesons are presented, providing a baseline for studying the charm hadronization in lead-lead collisions at LHC energies. |
Address |
[de Souza Leite, J. Baptista; Bediaga, I. B.; Torres, M. Cruz; Carneiro Da Graca, U. De Freitas; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massaferri, A.; Santoro, L.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil, Email: yiheng.luo@cern.ch |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1029-8479 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes ![sorted by Notes field, descending order (down)](img/sort_desc.gif) |
WOS:001190227500001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
6021 |
Permanent link to this record |
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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.; Sanderswood, I.; Zhuo, J. |
Title |
Search for CP violation in the phase space of D0 → KS0 K± π∓ decays with the energy test |
Type |
Journal Article |
Year |
2024 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
03 |
Issue |
3 |
Pages |
107 - 20pp |
Keywords |
Charm Physics; CP Violation; Hadron-Hadron Scattering |
Abstract |
A search for CP violation in D-0 -> (KSK+)-K-0 pi(-) and D-0 -> (KSK-)-K-0 pi(+) decays is reported. The search is performed using an unbinned model-independent method known as the energy test that probes local CP violation in the phase space of the decays. The data analysed correspond to an integrated luminosity of 5.4 fb(-1) collected in proton-proton collisions by the LHCb experiment at a centre-of-mass energy of root s = 13TeV, amounting to approximately 950 thousand and 620 thousand signal candidates for the D-0 -> (KSK-)-K-0 pi(+) and D-0 -> (KSK+)-K-0 pi(-) modes, respectively. The method is validated using D-0 -> K-pi(+)pi(-)pi(+) and D-0 -> K-S(0)pi(+)pi(-) decays, where CP-violating effects are expected to be negligible, and using background-enhanced regions of the signal decays. The results are consistent with CP symmetry in both the D-0 -> (KSK-)-K-0 pi(+) and the D-0 -> (KSK+)-K-0 pi(-) decays, with p-values for the hypothesis of no CP violation of 70% and 66%, respectively. |
Address |
[Egede, U.; Fujii, Y.; Hadavizadeh, T.; Henderson, R. D. L.; Lane, J. J.; Monk, M.; Singla, M.; Song, R.; Walton, E. J.; Ward, J. A.] Monash Univ, Sch Phys & Astron, Melbourne, Vic, Australia, Email: gianluca.zunica@epfl.ch |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1029-8479 |
ISBN |
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Notes ![sorted by Notes field, descending order (down)](img/sort_desc.gif) |
WOS:001190072500001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
6124 |
Permanent link to this record |