Records |
Author |
Mavromatos, N.E.; Mitsou, V.A.; Sarkar, S.; Vergou, A. |
Title |
Implications of a stochastic microscopic Finsler cosmology |
Type |
Journal Article |
Year |
2012 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
Volume |
72 |
Issue |
3 |
Pages |
1956 - 38pp |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
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Abstract |
Within the context of supersymmetric space-time (D-particle) foam in string/brane-theory, we discuss a Finsler-induced cosmology and its implications for (thermal) dark matter abundances. This constitutes a truly microscopic model of dynamical space-time, where Finsler geometries arise naturally. The D-particle foam model involves point-like brane defects (D-particles), which provide the topologically non-trivial foamy structures of space-time. The D-particles can capture and emit stringy matter and this leads to a recoil of D-particles. It is indicated how one effect of such a recoil of D-particles is a back-reaction on the space-time metric of Finsler type which is stochastic. We show that such a type of stochastic space-time foam can lead to acceptable cosmologies at late epochs of the Universe, due to the non-trivial properties of the supersymmetric (BPS like) D-particle defects, which are such so as not to affect significantly the Hubble expansion. The restrictions placed on the free parameters of the Finsler type metric are obtained from solving the Boltzmann equation in this background for relic abundances of a Lightest Supersymmetric Particle (LSP) dark matter candidate. It is demonstrated that the D-foam acts as a source for particle production in the Boltzmann equation, thereby leading to enhanced thermal LSP relic abundances relative to those in the Standard Lambda CDM cosmology. For D-particle masses of order TeV, such effects may be relevant for dark matter searches at colliders. The latter constraints complement those coming from high-energy gamma-ray astronomy on the induced vacuum refractive index that D-foam models entail. We also comment briefly on the production mechanisms of such TeV-mass stringy defects at colliders, which, in view of the current LHC experimental searches, will impose further constraints on their couplings. |
Address |
[Mavromatos, Nick E.; Sarkar, Sarben; Vergou, Ariadne] Univ London, Univ London Kings Coll, Dept Phys, London WC2R 2LS, England, Email: Nikolaos.Mavromatos@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 |
1434-6044 |
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:000302540000001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
982 |
Permanent link to this record |
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Author |
Bernal, A.; Perez, A. |
Title |
Analytic behavior of the QED polarizability function at finite temperature |
Type |
Journal Article |
Year |
2012 |
Publication |
AIP Advances |
Abbreviated Journal |
AIP Adv. |
Volume |
2 |
Issue |
1 |
Pages |
012152 - 9pp |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
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Abstract |
We revisit the analytical properties of the static quasi-photon polarizability function for an electron gas at finite temperature, in connection with the existence of Friedel oscillations in the potential created by an impurity. In contrast with the zero temperature case, where the polarizability is an analytical function, except for the two branch cuts which are responsible for Friedel oscillations, at finite temperature the corresponding function is non analytical, in spite of becoming continuous everywhere on the complex plane. This effect produces, as a result, the survival of the oscillatory behavior of the potential. We calculate the potential at large distances, and relate the calculation to the non-analytical properties of the polarizability. |
Address |
[Bernal, A.] Univ Barcelona, Dept Matemat Aplicada & Anal, E-08028 Barcelona, Spain |
Corporate Author |
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Thesis |
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Publisher |
Amer Inst Physics |
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 |
2158-3226 |
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:000302225400070 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
983 |
Permanent link to this record |
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Author |
Giusarma, E.; Archidiacono, M.; de Putter, R.; Melchiorri, A.; Mena, O. |
Title |
Sterile neutrino models and nonminimal cosmologies |
Type |
Journal Article |
Year |
2012 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
85 |
Issue |
8 |
Pages |
083522 - 9pp |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
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Abstract |
Cosmological measurements are affected by the energy density of massive neutrinos. We extend here a recent analysis of current cosmological data to nonminimal cosmologies. Several possible scenarios are examined: a constant w not equal -1 dark energy equation of state, a nonflat universe, a time-varying dark energy component and coupled dark matter-dark energy universes or modified gravity scenarios. When considering cosmological data only, (3 + 2) massive neutrino models with similar to 0.5 eV sterile species are allowed at 95% confidence level. This scenario has been shown to reconcile reactor, LSND and MiniBooNE positive signals with null results from other searches. Big bang nucleosynthesis bounds could compromise the viability of (3 + 2) models if the two sterile species are fully thermalized states at decoupling. |
Address |
[Giusarma, Elena; de Putter, Roland; Mena, Olga] Univ Valencia CSIC, IFIC, Valencia 46071, Spain |
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 |
1550-7998 |
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:000303118100002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
984 |
Permanent link to this record |
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Author |
BABAR Collaboration (Lees, J.P. et al); Martinez-Vidal, F.; Oyanguren, A. |
Title |
Search for the Z(1)(4050)(+) and Z(2)(4250)(+) states in (B)over-bar(0) -> chi K-c1(-)pi(+) and B+ -> chi K-c1(S)0 pi(+) |
Type |
Journal Article |
Year |
2012 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
85 |
Issue |
5 |
Pages |
052003 - 12pp |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
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Abstract |
We search for the Z(1)(4050)(+) and Z(2)(4250)(+) states, reported by the Belle Collaboration, decaying to chi(c1)pi(+) in the decays (B) over bar (0) -> chi K-c1(-)pi(+) and B+ -> chi K-c1(S)0 pi(+) where chi(c1) -> J/psi gamma. The data were collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) collider operating at center-of-mass energy 10.58 GeV, and correspond to an integrated luminosity of 429 fb(-1). In this analysis, we model the background-subtracted, efficiency-corrected chi(c1)pi(+) mass distribution using the K pi mass distribution and the corresponding normalized K pi Legendre-polynomial moments, and then test the need for the inclusion of resonant structures in the description of the chi(c1)pi(+) mass distribution. No evidence is found for the Z(1)(4050)(+) and Z(2)(4250)(+) resonances, and 90% confidence level upper limits on the branching fractions are reported for the corresponding B-meson decay modes. |
Address |
[Lees, J. P.; Poireau, V.; Tisserand, V.] Univ Savoie, CNRS, IN2P3, Lab Annecy le Vieux Phys Particules LAPP, 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 |
1550-7998 |
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:000301573100002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
985 |
Permanent link to this record |
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Author |
Haider, H.; Ruiz Simo, I.; Sajjad Athar, M. |
Title |
nu((nu)over-bar)-Pb-208 deep-inelastic scattering |
Type |
Journal Article |
Year |
2012 |
Publication |
Physical Review C |
Abbreviated Journal |
Phys. Rev. C |
Volume |
85 |
Issue |
5 |
Pages |
055201 - 11pp |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
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Abstract |
Nuclear-medium effects on the weak structure functions F-2(x, Q(2)) and F-3(x, Q(2)) in charged-current neutrino and antineutrino induced deep-inelastic reactions in Pb-208 have been studied. The calculations have been performed in a theoretical model using relativistic nuclear spectral functions which incorporate Fermi motion, binding, and nucleon correlations. We have also included the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. Using these structure functions, differential scattering cross sections have been obtained and compared with the CERN Hybrid Oscillation Research Apparatus (CHORUS) data. The results for the ratios 2F(i)(Pb)/208F(i)(D), 4F(i)(Pb)/208F(i)(He), 12F(i)(Pb)/208F(i)(C), 16F(i)(Pb)/208F(i)(O), and 56F(i)(Pb)/208F(i)(Fe) (i = 2, 3) have also been obtained and compared with some of the phenomenological fits. |
Address |
[Haider, H.; Athar, M. Sajjad] Aligarh Muslim Univ, Dept Phys, Aligarh 202002, Uttar Pradesh, India, Email: sajathar@gmail.com |
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 |
0556-2813 |
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:000303657200007 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
1002 |
Permanent link to this record |