Records |
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. |
Title |
Isospin Amplitudes in Lambda(0)(b) -> J/psi Lambda (Sigma(0)) and Xi(0)(b)-> J/psi Xi(0) (Lambda) Decays |
Type |
Journal Article |
Year |
2020 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
124 |
Issue |
11 |
Pages |
111802 - 11pp |
Keywords |
|
Abstract |
Ratios of isospin amplitudes in hadron decays are a useful probe of the interplay between weak and strong interactions and allow searches for physics beyond the standard model. We present the first results on isospin amplitudes in b-baryon decays, using data corresponding to an integrated luminosity of 8.5 fb(-1), collected with the LHCb detector in pp collisions at center of mass energies of 7, 8, and 13 TeV. The isospin amplitude ratio vertical bar A(1) (Delta(0)(b) -> J/psi(Sigma(0)) /A(0) (Delta(0)(b) -> J/psi Lambda)vertical bar, where the subscript on A indicates the final-state isospin, is measured to be less than 1/21.8 at 95% confidence level. The Cabibbo suppressed Xi(0)(b) -> J/psi Lambda decay is observed for the first time, allowing for the measurement vertical bar A(0) (Xi(0)(b) -> J/psi Lambda) / A(1/2 )(Xi(0)(b) -> J/psi Xi(0))vertical bar = 0.37 +/- 0.06 +/- 0.02, where the uncertainties are statistical and systematic, respectively. |
Address |
[Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Soares Lavra, L.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
0031-9007 |
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:000519994700005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4335 |
Permanent link to this record |
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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. |
Title |
Measurement of f(s)/f(u) Variation with Proton-Proton Collision Energy and B-Meson Kinematics |
Type |
Journal Article |
Year |
2020 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
124 |
Issue |
12 |
Pages |
122002 - 11pp |
Keywords |
|
Abstract |
The ratio of the B-s(0) and B+ fragmentation fractions f(s) and f(u) is studied with B-s(0) -> J/psi phi and B+ -> J/psi K+ decays using data collected by the LHCb experiment in proton-proton collisions at 7, 8, and 13 TeV center-of-mass energies. The analysis is performed in bins of B-meson momentum, longitudinal momentum, transverse momentum, pseudorapidity, and rapidity. The fragmentation-fraction ratio f(s)/f(u) is observed to depend on the B-meson transverse momentum with a significance of 6.0 sigma. This dependency is driven by the 13 TeV sample (8.7 sigma), while the results for the other collision energies are not significant when considered separately. Furthermore, the results show a 4.8 sigma evidence for an increase of f(s)/f(u) as a function of collision energy. |
Address |
[Bediaga, I; Cruz Torres, M.; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Soares Lavra, L.] CBPF, Rio De Janeiro, Brazil |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
0031-9007 |
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:000522195100005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4352 |
Permanent link to this record |
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Author |
Belle II Collaboration (Adachi, I. et al); Gomis, P.; Marinas, C. |
Title |
Search for an Invisibly Decaying Z ' Boson at Belle II in e(+)e(-) -> mu(+)mu(-) (e(+/-)mu(-/+)) Plus Missing Energy Final States |
Type |
Journal Article |
Year |
2020 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
124 |
Issue |
14 |
Pages |
141801 - 9pp |
Keywords |
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Abstract |
Theories beyond the standard model often predict the existence of an additional neutral boson, the Z'. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z' in the process e(+)e(-) -> mu(+)mu(-) Z' and of a lepton-flavor-violating Z' in e(+) e(-) -> e(+/-)mu(-/+)Z'. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an L, – L, theory, into upper limits on the Z' coupling constant at the level of 5 x 10(-2) – 1 for M-z' <= 6 GeV/c(2). |
Address |
[Jia, S.; Shen, C. P.; Zhou, X. Y.] Beihang Univ, Beijing 100191, Peoples R China |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
0031-9007 |
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:000523637800002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4362 |
Permanent link to this record |
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Author |
Euve, L.P.; Robertson, S.; James, N.; Fabbri, A.; Rousseaux, G. |
Title |
Scattering of Co-Current Surface Waves on an Analogue Black Hole |
Type |
Journal Article |
Year |
2020 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
124 |
Issue |
14 |
Pages |
141101 - 6pp |
Keywords |
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Abstract |
We report on what is to our knowledge the first scattering experiment of surface waves on an accelerating transcritical flow, which in the analogue gravity context is described by an effective spacetime with a black-hole horizon. This spacetime has been probed by an incident co-current wave, which partially scatters into an outgoing countercurrent wave on each side of the horizon. The measured scattering amplitudes are compatible with the predictions of the hydrodynamical theory, where the kinematical description in terms of the effective metric is exact. |
Address |
[Euve, Leo-Paul] Univ Paris Diderot, Univ PSL, Lab Phys & Mecan Milieux Heterogenes, CNRS,Sorbonne Univ,UMR 7636,ESPCI, 10 Rue Vauquelin, F-75321 Paris 05, France |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
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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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 |
0031-9007 |
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:000524336600002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4364 |
Permanent link to this record |
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Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
Title |
Measurements of the Absolute Branching Fractions of B-+/- -> K(+/-)Xc(c)over-bar |
Type |
Journal Article |
Year |
2020 |
Publication ![sorted by Publication field, descending order (down)](img/sort_desc.gif) |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
124 |
Issue |
15 |
Pages |
152001 - 8pp |
Keywords |
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Abstract |
A study of the two-body decays B-+/- -> Xc (c) over barK +/-, where X-c (c) over bar refers to one charmonium state, is reported by the BABAR Collaboration using a data sample of 424 fb(-1). The absolute determination of branching fractions for these decays are significantly improved compared to previous BABAR measurements. Evidence is found for the decay B-+/- -> X(3872)K+ at the 3 sigma level. The absolute branching fraction B[B+ -> X(3872)K+] = [2.1 +/- 0.6(stat) +/- 0.3(syst)] x 10(-4) is measured for the first time. It follows that B[X(3872) -> J/psi pi(+)pi(-)] = (4.1 +/- 1.3)%, supporting the hypothesis of a molecular component for this resonance. |
Address |
[Lees, J. P.; Poireau, V; Tisserand, V; BABAR Collaboration] Univ Savoie, Lab Annecy le Vieux Phys Particules LAPP, IN2P3, CNRS, F-74941 Annecy Le Vieux, France |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
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 |
0031-9007 |
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:000526038600003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4373 |
Permanent link to this record |