Abstract
Self-interacting dark matter (SIDM) was introduced by Spergel and Steinhardt to address possible discrepancies between collisionless dark matter simulations and observations on scales of less than 1 Mpc. We examine the case in which dark matter particles not only have strong self-interactions but also have strong interactions with baryons. The presence of such interactions will have direct implications for nuclear and particle astrophysics. Among these are a change in the predicted abundances from big bang nucleosynthesis (BBN) and the flux of rays produced by the decay of neutral pions which originate in collisions between dark matter and galactic cosmic rays (CR). From these effects we constrain the strength of the baryon–dark-matter interactions through the ratio of baryon–dark-matter interaction cross section to dark matter mass, s. We find that BBN places a weak upper limit on this ratio CR-SIDM interactions, however, limit the possible DM-baryon cross section to this rules out an energy-independent interaction, but not one which falls with center-of-mass velocity or steeper.
- Received 8 January 2002
DOI:https://doi.org/10.1103/PhysRevD.65.123503
©2002 American Physical Society