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Author Barenboim, G.; Park, W.I.
Title A full picture of large lepton number asymmetries of the Universe Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 04 Issue 4 Pages 048 - 10pp
Keywords cosmological neutrinos; cosmology of theories beyond the SM; leptogenesis; physics of the early universe
Abstract A large lepton number asymmetry of O(0.1-1) at present Universe might not only be allowed but also necessary for consistency among cosmological data. We show that, if a sizeable lepton number asymmetry were produced before the electroweak phase transition, the requirement for not producing too much baryon number asymmetry through sphalerons processes, forces the high scale lepton number asymmetry to be larger than about 30. Therefore a mild entropy release causing O(10-100) suppression of pre-existing particle density should take place, when the background temperature of the Universe is around T = O(10(-2) -10(2)) GeV for a large but experimentally consistent asymmetry to be present today. We also show that such a mild entropy production can be obtained by the late-time decays of the saxion, constraining the parameters of the Peccei-Quinn sector such as the mass and the vacuum expectation value of the saxion field to be m(phi) greater than or similar to O(10) TeV and phi(0) greater than or similar to O(10(14)) GeV, respectively.
Address (up) [Barenboim, Gabriela] Univ Valencia, CSIC, Dept Fis Teor, C Dr Moliner 50, E-46100 Burjassot, Spain, Email: Gabriela.Barenboim@uv.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000401806200048 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3148
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Author Barenboim, G.; Salvado, J.
Title Cosmology and CPT violating neutrinos Type Journal Article
Year 2017 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 77 Issue 11 Pages 766 - 18pp
Keywords
Abstract The combination charge conjugation-parity-time reversal (CPT) is a fundamental symmetry in our current understanding of nature. As such, testing CPT violation is a strongly motivated path to explore new physics. In this paper we study CPT violation in the neutrino sector, giving for the first time a bound, for a fundamental particle, in the CPT violating particle-antiparticle gravitational mass difference. We argue that cosmology is nowadays the only data sensitive to CPT violation for the neutrino-antineutrino mass splitting and we use the latest data release from Planck combined with the current baryonic-acoustic-oscillation measurement to perform a full cosmological analysis. To show the potential of the future experiments we also show the results for Euclid, a next generation large scale structure experiment.
Address (up) [Barenboim, Gabriela] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: Gabriela.Barenboim@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:000415376100002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3378
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Author Barenboim, G.; Park, W.I.
Title Lepton number asymmetries and the lower bound on the reheating temperature Type Journal Article
Year 2017 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 12 Issue 12 Pages 037 - 13pp
Keywords cosmological neutrinos; physics of the early universe
Abstract We show that the reheating temperature of a matter-domination era in the early universe can be pushed down to the neutrino decoupling temperature at around 2 MeV if the reheating takes place through non-hadronic decays of the dominant matter and neutrino-antineutrino asymmetries are still large enough, vertical bar L vertical bar greater than or similar to O(10(-2)) (depending on the neutrino flavor) at the end of reheating.
Address (up) [Barenboim, Gabriela] Univ Valencia, Dept Fis Teor, CSIC, E-46100 Burjassot, Spain, Email: Gabriela.Barenboim@uv.es;
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1475-7516 ISBN Medium
Area Expedition Conference
Notes WOS:000418672700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3430
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Author NA48/2 Collaboration (Batley, J.R. et al); Fiorini, L.
Title Searches for lepton number violation and resonances in K-+/- -> pi μμdecays Type Journal Article
Year 2017 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 769 Issue Pages 67-76
Keywords
Abstract The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003-2004. A new upper limit on the rate of the lepton number violating decay K-+/- -> pi(+/-)mu(+/-)mu(+/-) is reported: B( K-+/- -> pi(+/-)mu(+/-)mu(+/-)) < 8.6 x 10(-11) at 90% CL. Searches for two-body resonances X in K-+/- -> pi μμdecays (such as heavy neutral leptons N-4 and inflatons chi) are also presented. In the absence of signals, upper limits are set on the products of branching fractions B(K-+/- -> μN-+/-(4))B(N-4 -> pi mu) and B(K-+/- ->pi X-+/-)B(X -> mu(+),mu(-)) for ranges of assumed resonance masses and lifetimes. The limits are in the (10(-11),10(-9)) range for resonance lifetimes below 100 ps.
Address (up) [Batley, J. R.; Kalmus, G.; Lazzeroni, C.; Munday, D. J.; Slater, M. W.; Wotton, S. A.] Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England, Email: karim.massri@cern.ch
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:000402342500011 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3169
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Author Bayar, M.; Debastiani, V.R.
Title a(0)(980) – f(0)(980) mixing in chi(c1) -> pi(0)f(0)(980) -> pi(0)pi(+)pi(-) and chi(c1) -> pi(0) a(0)(980) -> pi(0)pi(0)eta Type Journal Article
Year 2017 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 775 Issue Pages 94-99
Keywords Isospin-breaking; a(0)(980) – f(0)(980) mixing; Charmonium decays; Scalar meson states
Abstract We study the isospin breaking in the reactions chi(c1) -> pi(0)pi(+)pi(-) and chi(c1) -> pi(0)pi(0)eta and its relation to the a(0)(980) – f(0)(980) mixing, which was measured by the BESIII Collaboration. We show that the same theoretical model previously developed to study the chi(c1) -> eta pi(+)pi(-) reaction (also measured by BESIII), and further explored in the predictions to the eta(c) -> eta pi(+)pi(-), can be successfully employed in the present study. We assume that the chi(c1) behaves as an SU(3) singlet to find the weight in which trios of pseudoscalars are created, followed by the final state interaction of pairs of mesons to describe how the a(0)(980) and f(0)(980) are dynamically generated, using the chiral unitary approach in coupled channels. The isospin violation is introduced through the use of different masses for the charged and neutral kaons, either in the propagators of pairs of mesons created in the chi(c1) decay, or in the propagators inside the T matrix, constructed through the unitarization of the scattering and transition amplitudes of pairs of pseudoscalar mesons. We find that violating isospin inside the T matrix makes the pi(0)eta -> pi(+)pi(-) amplitude nonzero, which gives an important contribution and also enhances the effect of the K (K) over bar term. We also find that the most important effect in the total amplitude is the isospin breaking inside the T matrix, due to the constructive sum of pi(0)eta -> pi(+)pi(-) and K (K) over bar -> pi(+)pi(-), which is essential to get a good agreement with the experimental measurement of the mixing.
Address (up) [Bayar, M.] Kocaeli Univ, Dept Phys, TR-41380 Izmir, Turkey, Email: melahat.bayar@kocaeli.edu.tr;
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:000417190700014 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3432
Permanent link to this record