Status of indirect searches in the PAMELA and Fermi era

Understand

The detection of gamma-rays, antiprotons and positrons due to pair annihilation of dark matter particles in the Milky Way halo is a viable indirect technique to search for signatures of supersymmetric dark matter where the major challenge is the discrimination of the signal from the background generated by standard production mechanisms.

• The new PAMELA antiproton data are consistent with the standard secondary production and this allows us to constrain exotic contribution to the spectrum due to neutralino annihilations.
• In particular, we show that in the framework of minimal supergravity (mSUGRA), in a clumpy halo scenario (with clumpiness factor > 10) and for large values of tan(beta)> 55, almost all the parameter space allowed by WMAP is excluded.
• Instead, the PAMELA positron fraction data exhibit an excess that cannot be explained by secondary production.