Records |
Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
Title |
Observation of Two New Xi(-)(b) Baryon Resonances |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
114 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
6 |
Pages |
062004 - 9pp |
Keywords |
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Abstract |
Two structures are observed close to the kinematic threshold in the Xi(0)(b)pi(-) mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LEICb experiment. In the quark model, two baryonic resonances with quark content bds are expected in this mass region: the spin-parity J(P) = (1/2)(+) and J(P) = (3/2)(+) states, denoted Xi'(-)(b) and Xi*(-)(b). Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be m(Xi'(-)(b)) – m(Xi(0)(b)) – m(pi(-))=3.653 +/- 0.018 +/- 0.006 MeV/c(2), m(Xi*(-)(b)) – m(Xi(0)(b)) – m(pi(-)) = 23.96 +/- 0.12 +/- 0.06 MeV/e(2), Gamma(Xi*(-)(b)) = 1.65 +/- 0.31 +/- 0.10 MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of Gamma(Xi'(-)(b)) < 0.08 MeV at 95% confidence level. Relative production rates of these states are also reported. |
Address |
[Bediaga, I.; De Miranda, J. M.; Ferreira Rodrigues, F.; Gomes, A.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.] Ctr Brasileiro Pesquisas Fis, 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:000349490200004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2127 |
Permanent link to this record |
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Author |
Tain, J.L. et al; Valencia, E.; Algora, A.; Agramunt, J.; Rubio, B.; Estevez, E.; Jordan, M.D. |
Title |
Enhanced gamma-Ray Emission from Neutron Unbound States Populated in beta Decay |
Type |
Journal Article |
Year |
2015 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
115 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
6 |
Pages |
062502 - 5pp |
Keywords |
|
Abstract |
Total absorption spectroscopy is used to investigate the beta-decay intensity to states above the neutron separation energy followed by gamma-ray emission in Br-87,Br-88 and Rb-94. Accurate results are obtained thanks to a careful control of systematic errors. An unexpectedly large. intensity is observed in all three cases extending well beyond the excitation energy region where neutron penetration is hindered by low neutron energy. The gamma branching as a function of excitation energy is compared to Hauser-Feshbach model calculations. For Br-87 and Br-88 the gamma branching reaches 57% and 20%, respectively, and could be explained as a nuclear structure effect. Some of the states populated in the daughter can only decay through the emission of a large orbital angular momentum neutron with a strongly reduced barrier penetrability. In the case of neutron-rich Rb-94 the observed 4.5% branching is much larger than the calculations performed with standard nuclear statistical model parameters, even after proper correction for fluctuation effects on individual transition widths. The difference can be reconciled by introducing an enhancement of 1 order of magnitude in the photon strength to neutron strength ratio. An increase in the photon strength function of such magnitude for very neutron-rich nuclei, if it proves to be correct, leads to a similar increase in the (n, gamma) cross section that would have an impact on r process abundance calculations. |
Address |
[Tain, J. L.; Valencia, E.; Algora, A.; Agramunt, J.; Rubio, B.; Estevez, E.; Jordan, M. D.] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: tain@ific.uv.es |
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:000359059100002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2319 |
Permanent link to this record |
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Author |
AGATA Collaboration (Hadynska-Klek, K. et al); Gadea, A. |
Title |
Superdeformed and Triaxial States in Ca-42 |
Type |
Journal Article |
Year |
2016 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
117 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
6 |
Pages |
062501 - 7pp |
Keywords |
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Abstract |
Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in Ca-42 were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 0(2)(+) has been obtained and the role of triaxiality in the A similar to 40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time. |
Address |
[Hadynska-Klek, K.; Napiorkowski, P. J.; Zielinska, M.; Srebrny, J.; Abraham, T.; Iwanicki, J.; Jaworski, G.; Kisielinski, M.; Komorowska, M.; Kowalczyk, M.; Mierzejewski, J.; Ozmen, S. F.; Palacz, M.; Prochniak, L.; Rusek, K.; Wrzosek-Lipska, K.] Univ Warsaw, Heavy Ion Lab, Pasteura 5A, PL-02093 Warsaw, Poland |
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 |
|
Area |
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Expedition |
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Conference |
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Notes |
WOS:000380966400004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2776 |
Permanent link to this record |
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Author |
LHCb Collaboration (Aaij, R. et al); Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Valls, P.; Sanchez Mayordomo, C. |
Title |
Measurement of the CP Asymmetry in B-s(0) – (B)over-bar(s)(0) Mixing |
Type |
Journal Article |
Year |
2016 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
117 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
6 |
Pages |
061803 - 9pp |
Keywords |
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Abstract |
The CP asymmetry in the mixing of B-s(0) and (B) over bar (0)(s) mesons is measured in proton-proton collision data corresponding to an integrated luminosity of 3.0 fb(-1), recorded by the LHCb experiment at center-of-mass energies of 7 and 8 TeV. Semileptonic B-s(0) and (B) over bar (s) (0) decays are studied in the inclusive mode D-s(-/+)mu(+/-)nu((-)) X-mu with the D-s(-/+) mesons reconstructed in the K+K-pi(-/+) final state. Correcting the observed charge asymmetry for detection and background effects, the CP asymmetry is found to be a(sl)(s) = (0.39 +/- 0.26 +/- 0.20)%, where the first uncertainty is statistical and the second systematic. This is the most precise measurement of a(sl)(s) to date. It is consistent with the prediction from the standard model and will constrain new models of particle physics. |
Address |
[Archilli, F.; Bediaga, I.; De Miranda, J. M.; Rodrigues, F. Ferreira; Gomes, A.; Massafferri, A.; dos Reis, A. C.; Rodrigues, A. B.; Vieira, D.] Ctr Brasileiro Pesquisas Fis 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 |
|
Area |
|
Expedition |
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Conference |
|
Notes |
WOS:000381442800006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2811 |
Permanent link to this record |
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Author |
Miranda, O.G.; Tortola, M.; Valle, J.W.F. |
Title |
New Ambiguity in Probing CP Violation in Neutrino Oscillations |
Type |
Journal Article |
Year |
2016 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
117 |
Issue ![sorted by Issue field, ascending order (up)](img/sort_asc.gif) |
6 |
Pages |
061804 - 5pp |
Keywords |
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Abstract |
If neutrinos get mass via the seesaw mechanism the mixing matrix describing neutrino oscillations can be effectively nonunitary. We show that in this case the neutrino appearance probabilities involve a new CP phase phi associated with nonunitarity. This leads to an ambiguity in extracting the “standard” three-neutrino phase delta(CP), which can survive even after neutrino and antineutrino channels are combined. Its existence should be taken into account in the planning of any oscillation experiment aiming at a robust measurement of delta(CP). |
Address |
[Miranda, O. G.] Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Fis, Apdo Postal 14-740, Mexico City 07000, DF, Mexico, Email: omr@fis.cinvestav.mx; |
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 |
|
Edition |
|
ISSN |
0031-9007 |
ISBN |
|
Medium |
|
Area |
|
Expedition |
|
Conference |
|
Notes |
WOS:000381442800007 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2812 |
Permanent link to this record |