title: Primordial beryllium as a big bang calorimeter.
abstract: Many models of new physics including variants of supersymmetry predict metastable long-lived particles that can decay during or after primordial nucleosynthesis, releasing significant amounts of nonthermal energy. The hadronic energy injection in these decays leads to the formation of ⁹Be via the chain of nonequilibrium transformations: Energy(h)→T, ³He→⁶He, ⁶Li→⁹Be. We calculate the efficiency of this transformation and show that if the injection happens at cosmic times of a few hours the release of O(10 MeV) per baryon can be sufficient for obtaining a sizable ⁹Be abundance. The absence of a plateau structure in the ⁹Be/H abundance down to a O(10⁻¹⁴) level allows one to use beryllium as a robust constraint on new physics models with decaying or annihilating particles.
authors.affiliation: Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2L 2Y5, Canada. pospelov@uvic.ca
authors.forename: Maxim
authors.initials: M
authors.lastname: Pospelov
authors.forename: Josef
authors.initials: J
authors.lastname: Pradler