The Galactic 511-keV Signal, Hidden Valleys, and Supernovae

Speaker: Hooman Davoudiasl, Brookhaven National Laboratory

When: February 1, 2010 (Mon), 12:30PM to 01:30PM (add to my calendar)

This event is part of the HET Seminar Series.

Abstract:
We examine under what circumstances the INTEGRAL/SPI 511 keV signal
can originate from decays of MeV-scale composite states produced by:
(A) thermonuclear (type Ia) or (B) core collapse supernovae (SNe).
The requisite dynamical properties that would account for the observed
data are quite distinct, for cases (A) and (B). We show that these
requirements can be met in simple hidden valley models. An uncommon
feature of scenario (A) is that the dynamics of type Ia SNe, standard
candles for cosmological measurements, might be affected by our
mechanism. Simple models for scenario (B) include a long-lived
particle that could, under certain circumstances, be a viable dark
matter candidate. The appearance of long-lived particles in typical
models leads to cosmological constraints and we address how a
consistent cosmic history may be achieved.