IFIC Home

IFIC Literature Database

Home |  Show All |  Simple Search |  Advanced Search
Quick Search:
1-10 of 52 records found matching your query:
toggle visibility Search & Display Options
Select All    Deselect All << 1 2 3 4 5 6 >>
List View
 | 
Citations
 | 
Details
   print
  Records Links
Author Bernabeu, J.; Espriu, D.; Puigdomenech, D. url  doi
openurl 
  Title Gravitational waves in the presence of a cosmological constant Type Journal Article
  Year 2011 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 84 Issue 6 Pages 063523 - 13pp  
  Keywords  
  Abstract We derive the effects of a nonzero cosmological constant Lambda on gravitational wave propagation in the linearized approximation of general relativity. In this approximation, we consider the situation where the metric can be written as g(mu nu) = eta(mu nu) + h(mu nu)(Lambda) + h(mu nu)(W), h(mu nu)(Lambda,W) << 1, where h(mu nu)(Lambda) is the background perturbation and h(mu nu)(W) is a modification interpretable as a gravitational wave. For Lambda not equal 0, this linearization of Einstein equations is self-consistent only in certain coordinate systems. The cosmological Friedmann-Robertson-Walker coordinates do not belong to this class and the derived linearized solutions have to be reinterpreted in a coordinate system that is homogeneous and isotropic to make contact with observations. Plane waves in the linear theory acquire modifications of order root Lambda, both in the amplitude and the phase, when considered in Friedmann-Robertson-Walker coordinates. In the linearization process for h(mu nu), we have also included terms of order O(Lambda h(mu nu)). For the background perturbation h(mu nu)(Lambda), the difference is very small, but when the term h(mu nu)(W)Lambda is retained the equations of motion can be interpreted as describing massive spin-2 particles. However, the extra degrees of freedom can be approximately gauged away, coupling to matter sources with a strength proportional to the cosmological constant itself. Finally, we discuss the viability of detecting the modifications caused by the cosmological constant on the amplitude and phase of gravitational waves. In some cases, the distortion with respect to gravitational waves propagating in Minkowski space-time is considerable. The effect of Lambda could have a detectable impact on pulsar timing arrays.  
  Address [Bernabeu, J] Univ Valencia, Dept Fis Teor IFIC, CSIC, E-46100 Valencia, Spain  
  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 WOS:000295223100005 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ elepoucu @ Serial 766  
Permanent link to this record
 
 
Author Bernabeu, J.; Martinez-Vidal, F.; Villanueva-Perez, P. url  doi
openurl 
  Title Time reversal violation from the entangled B-0(B)over-bar(0) system Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 08 Issue 8 Pages 064 - 18pp  
  Keywords Discrete and Finite Symmetries; B-Physics; CP violation  
  Abstract We discuss the concepts and methodology to implement an experiment probing directly Time Reversal (T) non-invariance, without any experimental connection to CP violation, by the exchange of in and out states. The idea relies on the B-0(B) over bar (0)) entanglement and decay time information available at B factories. The flavor or CP tag of the state of the still living neutral meson by the first decay of its orthogonal partner overcomes the problem of irreversibility for unstable systems, which prevents direct tests of T with incoherent particle states. T violation in the time evolution between the two decays means experimentally a difference between the rates for the time-ordered (l+X, J/psi K-s) and (J/psi K-L, l(-)X) decays, and three other independent asymmetries. The proposed strategy has been applied to simulated data samples of similar size and features to those currently available, from which we estimate the significance of the expected discovery to reach many standard deviations.  
  Address [Bernabeu, J.] Univ Valencia, Dept Theoret Phys, E-46100 Burjassot, Spain, Email: Jose.Bernabeu@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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000309883600021 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 1215  
Permanent link to this record
 
 
Author Bernabeu, J.; Botella, F.J.; Nebot, M. url  doi
openurl 
  Title Novel T-Violation observable open to any pair of decay channels at meson factories Type Journal Article
  Year 2014 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 728 Issue Pages 95-98  
  Keywords  
  Abstract Quantum entanglement between the two neutral mesons produced in meson factories has allowed the first indisputable direct observation of Time Reversal Violation in the time evolution of the neutral meson between the two decays. The exceptional meson transitions are directly connected to semileptonic and CP eigenstate decay channels. The possibility of extending the observable asymmetries to more decay channels confronts the problem of the “orthogonality condition”, which can be stated with this tonguetwister: Given a decay channel f, which is the decay channel f' such that the meson state not decaying to f is orthogonal to the meson state not decaying to f? In this Letter we propose an alternative T-Violation asymmetry at meson factories which allows its opening to any pair of decay channels. Instead of searching which is the pair of decay channels associated to the T-reverse meson transition, we build an asymmetry which tags the initial states of both the Reference and the T-reverse meson transitions. This observable filters the appropriate final states by means of two measurable survival probabilities. We discuss the methodology to be followed in the analysis of the new observable and the results expected in specific examples.  
  Address [Nebot, Miguel] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain, Email: Jose.Bernabeu@uv.es;  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000330556000017 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 1705  
Permanent link to this record
 
 
Author Bernabeu, J.; Martinez-Vidal, F. url  doi
openurl 
  Title Colloquium: Time-reversal violation with quantum-entangled B mesons Type Journal Article
  Year 2015 Publication Reviews of Modern Physics Abbreviated Journal Rev. Mod. Phys.  
  Volume 87 Issue 1 Pages 165-182  
  Keywords  
  Abstract Symmetry transformations have been proven a bedrock tool for understanding the nature of particle interactions, formulating, and testing fundamental theories. Based on the up to now unbroken CPT symmetry, the violation of the CP symmetry between matter and antimatter by weak interactions, discovered in the decay of kaons in 1964 and observed more recently in 2001 in B mesons, strongly suggests that the behavior of these particles under weak interactions must also be asymmetric under time reversal T. However, until recent years there has not been a direct detection of the expected time-reversal violation in the time evolution of any system. This Colloquium examines the field of time-reversal symmetry breaking in the fundamental laws of physics. For transitions, its observation requires an asymmetry with exchange of initial and final states. A discussion is given of the conceptual basis for such an exchange with unstable particles, using the quantum properties of Einstein-Podolsky-Rosen entanglement available at B meson factories combined with the decay as a filtering measurement. The method allows a clear-cut separation of different transitions between flavor and CP eigenstates in the decay of neutral B mesons. These ideas have been implemented for the experiment by the BABAR Collaboration at SLAC's B factory. The results, presented in 2012, prove beyond any doubt the violation of time-reversal invariance in the time evolution between these two states of the neutral B meson.  
  Address [Bernabeu, J.; Martinez-Vidal, F.] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: Jose.Bernabeu@uv.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 0034-6861 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000352076500001 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 2179  
Permanent link to this record
 
 
Author Bernabeu, J.; Martinez-Vidal, F. doi  openurl
  Title Time-Reversal Violation Type
  Year 2015 Publication Annual Review of Nuclear and Particle Science Abbreviated Journal Annu. Rev. Nucl. Part. Sci.  
  Volume 65 Issue Pages 403-427  
  Keywords time reversal; CP violation; T-odd products; electric dipole moments; B mesons; K mesons; EPR entanglement  
  Abstract The violation of CP symmetry between matter and antimatter in the neutral K and B meson systems is well established, with a high degree of consistency between all available experimental measurements and with the Standard Model of particle physics. On the basis of the up-to-now-unbroken CPT symmetry, the violation of CP symmetry strongly suggests that the behavior of these particles under weak interactions must also be asymmetric under time reversal T. Many searches for T violation have been performed and proposed using different observables and experimental approaches. These include T-odd observables, such as triple products in weak decays, and genuine observables, such as permanent electric dipole moments of nondegenerate stationary states and the breaking of the reciprocity relation. We discuss the conceptual basis of the required exchange of initial and final states with unstable particles, using quantum entanglement and the decay as a filtering measurement, for the case of neutral B and K mesons. Using this method, the BaBar experiment at SLAC has clearly observed T violation in B mesons.  
  Address [Bernabeu, Jose; Martinez-Vidal, Fernando] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain  
  Corporate Author Thesis  
  Publisher Annual Reviews Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0163-8998 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000363473100017 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 2430  
Permanent link to this record
 
 
Author Aguilar-Saavedra, J.A.; Bernabeu, J. url  doi
openurl 
  Title Breaking down the entire W boson spin observables from its decay Type Journal Article
  Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 93 Issue 1 Pages 011301 - 6pp  
  Keywords  
  Abstract We discuss the eight independent spin observables for the W boson in terms of its vector and tensor polarizations and identify the angular distributions and asymmetries able to separate them in collider experiments. The results are applied to the study of polarized top quark decays and diboson resonances. These novel observables are of great value for disentangling new physics mechanisms in W boson production.  
  Address [Aguilar-Saavedra, J. A.] Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain  
  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 WOS:000368324500001 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 2538  
Permanent link to this record
 
 
Author Bernabeu, J. url  doi
openurl 
  Title Discrete Symmetries CP,T,CPT Type Journal Article
  Year 2016 Publication Acta Physica Polonica B Abbreviated Journal Acta Phys. Pol. B  
  Volume 47 Issue 2 Pages 417-424  
  Keywords  
  Abstract The role of symmetry breaking mechanisms to search for new physics is of highest importance. We discuss the status and prospects of the discrete symmetries CP, T, CPT looking for their separate violation in LHC experiments and meson factories.  
  Address [Bernabeu, Jose] Univ Valencia, Dept Theoret Phys, E-46003 Valencia, Spain, Email: jose.bernabeu@uv.es  
  Corporate Author Thesis  
  Publisher Wydawnictwo Uniwersytetu Jagiellonskiego Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0587-4254 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000373493700022 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 2628  
Permanent link to this record
 
 
Author Barenboim, G.; Bernabeu, J.; Mitsou, V.A.; Romero Adam, E.; Vives, O. url  doi
openurl 
  Title METing SUSY on the Z peak Type Journal Article
  Year 2016 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C  
  Volume 76 Issue 2 Pages 57 - 13pp  
  Keywords  
  Abstract Recently the ATLAS experiment announced a 3 sigma excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E-T(miss) > 225 GeV and H-T > 600 GeV, to be compared with 10.6 +/- 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m((g) over bar) less than or similar to 1.2 TeV, together with a heavy neutralino NLSP of m((chi) over bar) greater than or similar to 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out.  
  Address [Barenboim, G.; Bernabeu, J.; Vives, O.] Univ Valencia, Dept Fis Teor, C Dr Moliner 50, E-46100 Burjassot, Spain, Email: oscar.vives@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 1434-6044 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000375278800001 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 2662  
Permanent link to this record
 
 
Author Bernabeu, J.; Botella, F.J.; Nebot, M. url  doi
openurl 
  Title Genuine T, CP, CPT asymmetry parameters for the entangled B-d system Type Journal Article
  Year 2016 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 06 Issue 6 Pages 100 - 24pp  
  Keywords Discrete Symmetries; Space-Time Symmetries  
  Abstract The precise connection between the theoretical T, CP, CPT asymmetries, in terms of transition probabilities between the filtered neutral meson B-d states, and the experimental asymmetries, in terms of the double decay rate intensities for Flavour-CP eigenstate decay products in a B-d-factory of entangled states, is established. This allows the identification of genuine Asymmetry Parameters in the time distribution of the asymmetries and their measurability by disentangling genuine and possible fake terms. We express the nine asymmetry parameters three different observables for each one of the three symmetries in terms of the ingredients of the Weisskopf-Wigner dynamical description of the entangled B-d-meson states and we obtain a global fit to their values from the BaBar collaboration experimental results. The possible fake terms are all compatible with zero and the information content of the nine asymmetry parameters is indeed different. The non -vanishing Delta l(c)(T) = 0.687 +/- 0.020 and Delta l(c)(CP) = 0.680 +/- 0.021 are impressive separate direct evidence of Time -Reversal -violation and CP-violation in these transitions and compatible with Standard Model expectations. An intriguing 2 sigma effect for the Re(theta) parameter responsible of CPT -violation appears which, interpreted as an upper limit, leads to vertical bar M (B) over baro (B) over baro vertical bar MBoBo < 4.0 x 10(-5) eV at 95% C.L. for the diagonal flavour terms of the mass matrix. It contributes to the CP-violating Delta l(c)(CP) asymmetry parameter in an unorthodox manner – in its cos(Delta M t) time dependence-, and it is accessible in facilities with non-entangled B-d's, like the LHCb experiment.  
  Address [Bernabeu, Jose] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: Jose.Bernabeu@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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000379028400001 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 2752  
Permanent link to this record
 
 
Author Aguilar-Saavedra, J.A.; Bernabeu, J.; Mitsou, V.A.; Segarra, A. url  doi
openurl 
  Title The Z boson spin observables as messengers of new physics Type Journal Article
  Year 2017 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C  
  Volume 77 Issue 4 Pages 234 - 6pp  
  Keywords  
  Abstract We demonstrate that the eight multipole parameters describing the spin state of the Z boson are able to disentangle known Z production mechanisms and signals from new physics at the LHC. They can be extracted from appropriate asymmetries in the angular distribution of lepton pairs from the Z boson decay. The power of this analysis is illustrated by (1) the production of Z boson plus jets; (2) Z boson plus missing transverse energy; (3) W and Z bosons originating from the two-body decay of a heavy resonance.  
  Address [Aguilar-Saavedra, J. A.] Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain, Email: jaas@ugr.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 1434-6044 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000399448700004 Approved no  
  Is ISI yes International Collaboration (up) no  
  Call Number IFIC @ pastor @ Serial 3121  
Permanent link to this record
Select All    Deselect All << 1 2 3 4 5 6 >>
List View
 | 
Citations
 | 
Details
   print
toggle visibility
Save Citations:
Export Records:
Home CQL Search  |  Library Search  |  Show Record  |  Extract Citations Help
ific federMinisterio de Ciencia e InnovaciónAgencia Estatal de Investigaciongva