Records |
Author |
LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J. |
Title |
Observation of a Lambda(0)(b) – (Lambda)over-bar(b)(0) production asymmetry in proton-proton collisions at root s=7 and 8 TeV |
Type |
Journal Article |
Year |
2021 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
10 |
Issue |
10 |
Pages |
060 - 38pp |
Keywords |
Hadron-Hadron scattering (experiments); Heavy quark production; proton-proton scattering; Hard scattering; B physics |
Abstract |
This article presents differential measurements of the asymmetry between Lambda(0)(b) and (Lambda) over bar (0)(b) baryon production rates in proton-proton collisions at centre-of-mass energies of root s = 7 and 8 TeV collected with the LHCb experiment, corresponding to an integrated luminosity of 3 fb(-1). The Lambda(0)(b) baryons are reconstructed through the inclusive semileptonic decay Lambda(0)(b) -> Lambda(+)(c) mu(-)(nu) over bar X-mu. The production asymmetry is measured both in intervals of rapidity in the range 2:15 < y < 4:10 and transverse momentum in 2 < p T < 27 GeV/c. The results are found to be incompatible with symmetric production with a significance of 5.8 standard deviations for both root s = 7 and 8 TeV data, assuming no CP violation in the decay. There is evidence for a trend as a function of rapidity with a significance of 4 standard deviations. Comparisons to predictions from hadronisation models in Pythia and heavy-quark recombination are provided. This result constitutes the first observation of a particle-antiparticle asymmetry in b-hadron production at LHC energies. |
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: sascha.stahl@cern.ch |
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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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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000705235400002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4985 |
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 |
Evidence for the decays B0 → (D)over-bar(*)0 φ and updated measurements of the branching fractions of the Bs0 → (D)over-bar(*)0 φ decays |
Type |
Journal Article |
Year |
2023 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
10 |
Issue |
10 |
Pages |
123 - 26pp |
Keywords |
B Physics; Branching fraction; Hadron-Hadron Scattering; CKM Angle Gamma |
Abstract |
Evidence for the decays B-0 -> (D) over bar (0)phi and B-0 -> (D) over bar (*0) phi is reported with a significance of 3.6 sigma and 4.3 sigma, respectively. The analysis employs pp collision data at centre-of-mass energies root s = 7, 8 and 13TeV collected by the LHCb detector and corresponding to an integrated luminosity of 9 fb(-1). The branching fractions are measured to be B(B-0 -> (D) over bar (0)phi) = (7.7 +/- 2.1 +/- 0.7 +/- 0.7) x 10(-7), B(B-0 -> (D) over bar (*0)phi) = (2.2 +/- 05 +/- 0.2 +/- 0.2) x 10(-6). In these results, the first uncertainty is statistical, the second systematic, and the third is related to the branching fraction of the B-0 -> (D) over bar K-0(+) K- decay, used for normalisation. By combining the branching fractions of the decays B-0 -> (D) over bar ((*)0)phi and B-0 -> (D) over bar ((*)0)omega, the omega-phi mixing angle delta is constrained to be tan(2)delta = (3.6 +/- 0.7 +/- 0.4) x 10(-3), where the first uncertainty is statistical and the second systematic. An updated measurement of the branching fractions of the B-s(0) -> (D) over bar ((*)0).phi decays, which can be used to determine the CKM angle gamma, leads to B(B-s(0) -> (D) over bar (0)phi) = (2.30 +/- 0.10 +/- 0.11 +/- 0.20) x 10(-5), B(B-s(0) -> (D) over bar (*0)phi) = (3.17 +/- 0.16 +/- 0.17 +/- 0.27) x 10(-5). |
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, Email: zhouxk@ccnu.edu.cn |
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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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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:001093260200001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5896 |
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 |
Observation of the decays B(s)0 → Ds1(2536)∓ K± |
Type |
Journal Article |
Year |
2023 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
10 |
Issue |
10 |
Pages |
106 - 25pp |
Keywords |
B Physics; Branching fraction; Flavour Physics; Hadron-Hadron Scattering |
Abstract |
This paper reports the observation of the decays B-(s)(0) -> D-s1(2536)K--/+(+/-) using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb(-1). The branching fractions of these decays are measured relative to the normalisation channel B-0 -> (D) over bar (K+K-)-K-0. The D-s1(2536)(-) meson is reconstructed in the (D) over bar*(2007)K-0(-) decay channel and the products of branching fractions are measured to be B(B-s(0) -> D-s1(2536)K--/+(+/-)) x B(D-s1(2536)(-) -> D ($) over bar*(2007)K-0(-)) = (2.49 +/- 0.11 +/- 0.12 +/- 0.25 +/- 0.06) x 10(-5), B(B-0 -> D-s1(2536)K--/+(+/-) ) x B(D-s1(2536)(-) -> (D) over bar*(2007)K-0(-)) = (0.510 +/- 0.021 +/- 0.036 +/- 0.050) x 10(-5). The first uncertainty is statistical, the second systematic, and the third arises from the uncertainty of the branching fraction of the B-0 -> (D) over bar (K+K-)-K-0 normalisation channel. The last uncertainty in the B-s(0) result is due to the limited knowledge of the fragmentation fraction ratio, f(s)/f(d). The significance for the B-s(0) and B-0 signals is larger than 10 sigma. The ratio of the helicity amplitudes which governs the angular distribution of the D-s1(2536)(-) -> (D) over bar*(2007)K-0(-) decay is determined from the data. The ratio of the S- and D-wave amplitudes is found to be 1.11 +/- 0.15 +/- 0.06 and the phase difference between them 0.70 +/- 0.09 +/- 0.04 rad, where the first uncertainty is statistical and the second systematic. |
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.; Santoro, L.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil, Email: zirui.w@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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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:001093237600001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5934 |
Permanent link to this record |
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Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
Title |
Measurement of CP asymmetry in B-s(0) -> D-s(-/+) K-/+ decays |
Type |
Journal Article |
Year |
2014 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
11 |
Issue |
11 |
Pages |
060 - 30pp |
Keywords |
CP violation; CKM angle gamma; B physics; Flavor physics; Hadron-Hadron Scattering |
Abstract |
We report on measurements of the time-dependent CP violating observables in B-s(0) -> D-s(-/+) K--/+ decays using a dataset corresponding to 1.0 fb(-1) of pp collisions recorded with the LHCb detector. We find the CP violating observables C-f = 0.53 +/- 0.25 +/- 0.04, A(f)(Delta Gamma) = 0.37 +/- 0.42 +/- 0.20, A((f) over bar)(Delta Gamma) = 0.20 +/- 0.41 +/- 0.20, S-f = -1.09 +/- 0.33 +/- 0.08, S-(f) over bar = -0.36 +/- 0.34 +/- 0.08, where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the B-s(0) mixing phase -2 beta(s) leads to the first extraction of the CKM angle gamma from B-s(0) -> D-s(-/+) K--/+ decays, finding gamma = (115(-43)(+28))degrees modulo 180 degrees at 68% CL, where the error contains both statistical and systematic uncertainties. |
Address |
[Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Hicheur, A.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.] CBPF, Rio De Janeiro, Brazil |
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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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000345080300001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2012 |
Permanent link to this record |
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Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
Title |
Determination of the quark coupling strength vertical bar V-ub vertical bar using baryonic decays |
Type |
Journal Article |
Year |
2015 |
Publication |
Nature Physics |
Abbreviated Journal |
Nat. Phys. |
Volume |
11 |
Issue |
9 |
Pages |
743-747 |
Keywords |
|
Abstract |
In the Standard Model of particle physics, the strength of the couplings of the b quark to the u and c quarks, vertical bar V-ub vertical bar and vertical bar V-ub vertical bar, are governed by the coupling of the quarks to the Higgs boson. Using data from the LHCb experiment at the Large Hadron Collider, the probability for the Lambda(0)(b) baryon to decay into the p mu(-)(nu) over bar (mu) final state relative to the Lambda(+)(c)mu(-)(nu) over bar (mu) final state is measured. Combined with theoretical calculations of the strong interaction and a previously measured value of vertical bar V-ub vertical bar, the first vertical bar V-ub vertical bar measurement to use a baryonic decay is performed. This measurement is consistent with previous determinations of vertical bar V-ub vertical bar using B meson decays to specific final states and confirms the existing incompatibility with those using an inclusive sample of final states. |
Address |
[Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Massafferri, A.; Rodrigues, B. Osorio; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: u.egede@imperial.ac.uk |
Corporate Author |
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Thesis |
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Publisher |
Nature Publishing Group |
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 |
1745-2473 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000360709200018 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2388 |
Permanent link to this record |