Dark matter: detecting the invisible

Melbourne physicists are trying to detect the undetectable – by searching for signs of its demise.

Nicole Bell and her colleagues at the University of Melbourne are analysing data on neutrinos, gamma and cosmic rays for evidence of the decay or annihilation of dark matter.

This mysterious material is suspected to exist because of the gravitational tug it exerts on the visible universe. But it has not, as yet, been found.

Further Information:

Indirect Detection of Particle Dark Matter

Nicole F. Bell
School of Physics, The University of Melbourne, Victoria 3010 Australia

Abstract Summary

We discuss indirect detection of dark matter, via annihilation or decay, and set model independent bounds using Galactic gammaray, neutrino and cosmic ray data. We explain the importance of electroweak bremsstrahlung


We discuss prospects for indirect detection of dark matter, via dark matter annihilation or decay in our Galaxy. We consider the production of gamma rays, neutrinos, or electron/positron final states, and use observational data to constrain the dark matter annihilation or decay processes in a model independent way. We discuss the implication of our bounds for models which seek to use annihilation or decay to modify the structure of dark matter halos. We examine radiative corrections to the lowest order decay/annihilation modes, namely bremsstrahlung and electroweak-bremsstralung, and describe scenarios in which they which make important (and in some cases, dominant) contributions to the observable fluxes. We discuss these annihilation/decay modes in light of recent cosmic ray positron and antiproton data.


Nicole Bell, n.bell@unimelb.edu.au