Addendum to "On an unverified nuclear decay and its role in the DAMA experiment''

We reply to the critiques of our paper arXiv:1210.5501 by the DAMA collaboration which appeared in arXiv:1210.6199 and arXiv:1211.6346. Our original claim that the observed background levels are likely to require a large modulation fraction of any putative signal holds. In fact, in light of DAMA's recent comment our claim is further corroborated. We identify the source of the discrepancy between our own analysis and DAMA's claimed levels of unmodulated background. Our analysis indicates that the background in the signal region as reported by DAMA is indeed likely underestimated.Comment: 6 pages, 2 figures; replacement of the original reply to arXiv:1210.6199 to include a response to the second critique in arXiv:1211.6346. A fit to the unmodulated rate including signal is presented. No change in the conclusion

CBBN in the CMSSM

Catalyzed big bang nucleosynthesis (CBBN) can lead to an overproduction of ^6Li in gravitino dark matter scenarios in which the lighter stau is the lightest Standard Model superpartner. Based on a treatment using the state-of-the-art result for the catalyzed ^6Li production cross section, we update the resulting constraint within the framework of the constrained minimal supersymmetric Standard Model (CMSSM). We confront our numerical findings with recently derived conservative limits on the gaugino mass parameter and the reheating temperature.Comment: 4 pages, 4 figures; Submitted for the SUSY07 proceeding

Signatures of Dark Radiation in Neutrino and Dark Matter Detectors

We consider the generic possibility that the Universe's energy budget includes some form of relativistic or semi-relativistic dark radiation (DR) with non-gravitational interactions with Standard Model (SM) particles. Such dark radiation may consist of SM singlets or a non-thermal, energetic component of neutrinos. If such DR is created at a relatively recent epoch, it can carry sufficient energy to leave a detectable imprint in experiments designed to search for very weakly interacting particles: dark matter and underground neutrino experiments. We analyze this possibility in some generality, assuming that the interactive dark radiation is sourced by late decays of an unstable particle, potentially a component of dark matter, and considering a variety of possible interactions between the dark radiation and SM particles. Concentrating on the sub-GeV energy region, we derive constraints on different forms of DR using the results of the most sensitive neutrino and dark matter direct detection experiments. In particular, for interacting dark radiation carrying a typical momentum of $\sim30$~MeV$/c$, both types of experiments provide competitive constraints. This study also demonstrates that non-standard sources of neutrino emission (e.g. via dark matter decay) are capable of creating a "neutrino floor" for dark matter direct detection that is closer to current bounds than is expected from standard neutrino sources.Comment: 12 pages, 6 figures; references added, typos corrected, conclusions unchanged; journal versio