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Title: Thermal production of gravitinos

Abstract

We reconsider thermal production of gravitinos in the early universe, adding to previously considered 2{yields}2 gauge scatterings: (a) production via 1{yields}2 decays, allowed by thermal masses: this is the main new effect, (b) the effect of the top Yukawa coupling, and (c) a proper treatment of the reheating process. Our final result behaves physically (larger couplings give a larger rate) and is twice larger than previous results, implying e.g. a constraint on the reheating temperature that is twice as strong. Accessory results about (supersymmetric) theories at finite temperature and gravitino couplings might have some pertinence.

Authors:
 [1];  [2]
  1. Scuola Normale Superiore and INFN, Piazza dei Cavalieri 7, I-56126 Pisa (Italy)
  2. Dipartimento di Fisica dell'Universita di Pisa and INFN (Italy)
Publication Date:
OSTI Identifier:
21020305
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 7; Other Information: DOI: 10.1103/PhysRevD.75.075011; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; GRAVITONS; PARTICLE DECAY; PARTICLE PRODUCTION; REST MASS; SCATTERING; SPARTICLES; SUPERSYMMETRY; UNIVERSE; YUKAWA POTENTIAL

Citation Formats

Rychkov, Vyacheslav S., and Strumia, Alessandro. Thermal production of gravitinos. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.075011.
Rychkov, Vyacheslav S., & Strumia, Alessandro. Thermal production of gravitinos. United States. doi:10.1103/PHYSREVD.75.075011.
Rychkov, Vyacheslav S., and Strumia, Alessandro. Sun . "Thermal production of gravitinos". United States. doi:10.1103/PHYSREVD.75.075011.
@article{osti_21020305,
title = {Thermal production of gravitinos},
author = {Rychkov, Vyacheslav S. and Strumia, Alessandro},
abstractNote = {We reconsider thermal production of gravitinos in the early universe, adding to previously considered 2{yields}2 gauge scatterings: (a) production via 1{yields}2 decays, allowed by thermal masses: this is the main new effect, (b) the effect of the top Yukawa coupling, and (c) a proper treatment of the reheating process. Our final result behaves physically (larger couplings give a larger rate) and is twice larger than previous results, implying e.g. a constraint on the reheating temperature that is twice as strong. Accessory results about (supersymmetric) theories at finite temperature and gravitino couplings might have some pertinence.},
doi = {10.1103/PHYSREVD.75.075011},
journal = {Physical Review. D, Particles Fields},
number = 7,
volume = 75,
place = {United States},
year = {Sun Apr 01 00:00:00 EDT 2007},
month = {Sun Apr 01 00:00:00 EDT 2007}
}
  • The impact of a kination-dominated phase generated by a quintessential exponen-tial model on the thermal abundance of gravitinos and axinos is investigated. We find that their abundances become proportional to the transition temperature from the kination to the radiation era; since this temperature is significantly lower than the initial (''reheating'') temperature, the abundances decrease with respect to their values in the standard cosmology. For values of the quintessential energy-density parameter close to its upper bound, on the eve of nucleosynthesis, we find the following: (i) for unstable gravitinos, the gravitino constraint is totally evaded; (ii) if the gravitino is stable,more » its thermal abundance is not sufficient to account for the cold dark matter of the universe; (iii) the thermal abundance of axinos can satisfy the cold dark matter constraint for values of the initial temperature well above those required in the standard cosmology. A novel calculation of the axino production rate by scatterings at low temperature is also presented.« less
  • We explicitly calculate nonthermal gravitino production during the preheating period in the inflationary Universe. Contrary to earlier investigations, we consider a two-field model to separate the mechanisms of supersymmetry breaking and inflation. We show that the superpartner of the inflaton is significantly generated, while the gravitino production is considerably smaller. Nonthermal production of gravitinos seems thus less worrisome than recently claimed.
  • We reanalyze the limits on the gravitino mass m{sub 3/2} in superlight gravitino scenarios derived from arguments on energy loss during gravitational collapse. We conclude that the mass range 10{sup {minus}6} eV{le}m{sub 3/2}{le}2.3{times}10{sup {minus}5} eV is excluded by SN 1987A data. In terms of the scale of supersymmetry breaking {Lambda}, the range 70 GeV {le}{Lambda}{le}300 GeV is not allowed. {copyright} {ital 1997} {ital The American Physical Society}
  • In models of spontaneously broken supersymmetry, certain light gravitino processes are governed by the coupling of their Goldstino components. The rules for constructing SUSY and gauge invariant actions involving the Goldstino couplings to matter and gauge fields are presented. The explicit operator construction is found to be at variance with some previously reported claims. A phenomenological consequence arising from light gravitino interactions in supernova is reexamined and scrutinized. {copyright} {ital 1998} {ital The American Physical Society}
  • No abstract prepared.