Richard H Cyburt et al JCAP11(2006)014 doi:10.1088/1475-7516/2006/11/014
Richard H Cyburt1, John Ellis2, Brian D Fields3, Keith A Olive4 and Vassilis C Spanos4
Show affiliationsIf the gravitino is the lightest supersymmetric particle and the long-lived next-to-lightest sparticle (NSP) is the stau, the charged partner of the tau lepton, it may be metastable and form bound states with several nuclei. These bound states may affect the cosmological abundances of 6Li and 7Li by enhancing nuclear rates that would otherwise be strongly suppressed. We consider the effects of these enhanced rates on the final abundances produced in Big-Bang nucleosynthesis (BBN), including injections of both electromagnetic and hadronic energy during and after BBN. We calculate the dominant two- and three-body decays of both neutralino and stau NSPs, and model the electromagnetic and hadronic decay products using the PYTHIA event generator and a cascade equation. Generically, the introduction of bound states drives light element abundances further from their observed values; however, for small regions of parameter space bound-state effects can bring lithium abundances in particular into better accord with observations. We show that in regions where the stau is the NSP with a lifetime longer than 103–104 s, the abundances of 6Li and 7Li are far in excess of those allowed by observations. For shorter lifetimes of order 1000 s, we comment on the possibility in minimal supersymmetric and supergravity models that stau decays could reduce the 7Li abundance from standard BBN values while at the same time enhancing the 6Li abundance.
E-print Number: astro-ph/0608562
Cited: by |
Refers: to
95.35.+d Dark matter (stellar, interstellar, galactic, and cosmological)
95.30.Cq Elementary particle processes
14.80.Ly Supersymmetric partners of known particles
Issue 11 (November 2006)
Received 7 September 2006, accepted for publication 2 November 2006
Published 30 November 2006
Richard H Cyburt et al JCAP11(2006)014
Richard H Cyburt et al JCAP11(2008)012
Richard H. Cyburt et al JCAP10(2009)021
A Becker et al 2007 J. Phys.: Conf. Ser. 88 012045
Francis C. Fekel et al. 2009 ApJ 695 1527
Ingo Schäfer and Klaus Krüger 2008 J. Phys. D: Appl. Phys. 41 045001
Gérard Petit and Sergei Klioner 2008 The Astronomical Journal 136 1909
Dennis D. McCarthy et al. 2008 The Astronomical Journal 136 1906
V S Filinov et al 2003 J. Phys. A: Math. Gen. 36 5905
Xiaobing Zou et al 2005 Plasma Sources Sci. Technol. 14 268