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Author Martinez-Asencio, J.; Olmo, G.J.; Rubiera-Garcia, D.
Title Black hole formation from a null fluid in extended Palatini gravity Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 86 Issue 10 Pages 104010 - 8pp
Keywords
Abstract We study the formation and perturbation of black holes by null fluxes of neutral matter in a quadratic extension of general relativity formulated a la Palatini. Working in a spherically symmetric space-time, we obtain an exact analytical solution for the metric that extends the usual Vaidya-type solution to this type of theory. We find that the resulting space-time is formally that of a Reissner-Nordstrom black hole but with an effective charge term carrying the wrong sign in front of it. This effective charge is directly related to the luminosity function of the radiation stream. When the ingoing flux vanishes, the charge term disappears and the space-time relaxes to that of a Schwarzschild black hole. We provide two examples that illustrate the formation of a black hole from Minkowski space and the perturbation by a finite pulse of radiation of an existing Schwarzschild black hole.
Address [Martinez-Asencio, Jesus; Olmo, Gonzalo J.] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: gonzalo.olmo@csic.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000310686900007 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1202
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Author BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A.; Villanueva-Perez, P.
Title Branching fraction and form-factor shape measurements of exclusive charmless semileptonic B decays, and determination of vertical bar V-ub vertical bar Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 86 Issue 9 Pages 092004 - 31pp
Keywords
Abstract We report the results of a study of the exclusive charmless semileptonic decays, B-0 -> pi(-)l(+)nu, B+ -> pi(0)l(+)nu, B+ -> omega l(+)nu, B+ -> eta l(+)nu, and B+ -> eta'l(+)nu (l = e or mu) undertaken with approximately 462 X 10(6) B (B) over bar pairs collected at the Upsilon(4S) resonance with the BABAR detector. The analysis uses events in which the signal B decays are reconstructed with a loose neutrino reconstruction technique. We obtain partial branching fractions in several bins of q(2), the square of the momentum transferred to the lepton-neutrino pair, for B-0 -> pi(-)l(+)nu, B+ -> pi(0)l(+)nu, B+ -> omega l(+)nu, and B+ -> eta l(+)nu. From these distributions, we extract the form-factor shapes f(+)(q(2)) and the total branching fractions B(B-0 -> pi(-)l(+)nu) = (1.45 +/- 0.04(stat) +/- 0.06(syst)) X 10(-4) (combined pi(-) and pi(0) decay channels assuming isospin symmetry), B(B+ -> omega l(+)nu) = (1.19 +/- 016(stat) +/- 0.09(syst)) X 10(-4) and B(B+ -> eta l(+)nu) = (0.38 +/- 0.05(stat) +/- 0.05(syst)) X 10(-4). We also measure B(B+ -> eta'l(+)nu) = (0.24 +/- 0.08(stat) +/- 0.03(syst)) X 10(-4). We obtain values for the magnitude of the Cabibbo-Kobayashi-Maskawa (KM) matrix element vertical bar V-ub vertical bar by direct comparison with three different QCD calculations in restricted q(2) ranges of B -> pi l(+)nu decays. From a simultaneous fit to the experimental data over the full q(2) range and the FNAL/MILC lattice QCD predictions, we obtain vertical bar V-ub vertical bar = (3.25 +/- 0.31) X 10(-3), where the error is the combined experimental and theoretical uncertainty.
Address [Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, Lab Annecy le Vieux Phys Particules LAPP, CNRS IN2P3, F-74941 Annecy Le Vieux, France
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000310686300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1201
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Author Martinez Torres, A.; Bayar, M.; Jido, D.; Oset, E.
Title Strategy to find the two Lambda (1405) states from lattice QCD simulations Type Journal Article
Year 2012 Publication Physical Review C Abbreviated Journal Phys. Rev. C
Volume 86 Issue 5 Pages 055201 - 13pp
Keywords
Abstract Theoretical studies within the chiral unitary approach, and recent experiments, have provided evidence of the existence of two isoscalar states in the region of the Lambda(1405). In this paper we use the same chiral approach to generate energy levels in a finite box. In a second step, assuming that these energies correspond to lattice QCD results, we devise the best strategy of analysis to obtain the two states in the infinite-volume case, with sufficient precision to distinguish them. We find out that by using energy levels obtained with asymmetric boxes and/or with a moving frame, with reasonable errors in the energies, one has a successful scheme to get the two Lambda(1405) poles.
Address [Torres, A. Martinez; Jido, D.] Kyoto Univ, Yukawa Inst Theoret Phys, Kyoto 6068502, Japan
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0556-2813 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000310685400008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1226
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Author Noguera, S.; Vento, V.
Title Model analysis of the world data on the pion transition form factor Type Journal Article
Year 2012 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 48 Issue 10 Pages 143 - 4pp
Keywords
Abstract We discuss the impact of recent Belle data on our description of the pion transition form factor based on the assumption that a perturbative formalism and a nonperturbative one can be matched in a physically acceptable manner at a certain hadronic scale Q(0). We discuss the implications of the different parameters of the model in comparing with world data and conclude that within experimental errors our description remains valid. Thus we can assert that the low Q(2) nonperturbative description together with an additional 1/Q(2) term at the matching scale have a strong influence on the Q(2) behavior up to very high values of Q(2).
Address [Noguera, S.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot Valencia, Spain, Email: Santiago.Noguera@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000310630100008 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 1198
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Author Xie, J.J.; Oset, E.
Title The DN, pi Sigma(c) interaction in finite volume and the Lambda(c)(2595) resonance Type Journal Article
Year 2012 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 48 Issue 10 Pages 146 - 10pp
Keywords
Abstract In this work the interaction of the coupled channels DN and pi Sigma(c) in an SU(4) extrapolation of the chiral unitary theory, where the Lambda(c)(2595) resonance appears as dynamically generated from that interaction, is extended to produce results in finite volume. Energy levels in the finite box are evaluated and, assuming that they would correspond to lattice results, the inverse problem of determining the phase shifts in the infinite volume from the lattice results is solved. We observe that it is possible to obtain accurate pi Sigma(c) phase shifts and the position of the Lambda(c)(2595) resonance, but it requires the explicit consideration of the two coupled channels. We also observe that some of the energy levels in the box are attached to the closed DN channel, such that their use to induce the pi Sigma(c) phase shifts via Luscher's formula leads to incorrect results.
Address [Xie, Ju-Jun] Zhengzhou Univ, Dept Phys, Zhengzhou 450001, Henan, Peoples R China, Email: xiejujun@ihep.ac.cn;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes (down) WOS:000310630100005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1199
Permanent link to this record