Quantifying galactic propagation uncertainty in WIMP dark matter search with AMS01 Z=-1 spectrum

Abstract

A search for a WIMP dark matter annihilation signal is carried out in the AMS01 negatively charged (Z=-I) particle spectrum, following a set of supersymmetric benchmark scenarios in the mSUGRA framework. The result is consistent with no dark matter, assuming a smooth isothermal distribution of dark matter in the Galactic halo. 90% upper bounds of the boost factor by which the flux from the DM annihilation could be enhanced without exceeding AMS01 data are derived to be - 10² - 10⁵, varied as different mSUGRA senarios. The Boron-to-Carbon ratio energy spectrum is measured with AMS01, which allows us to constrain the cosmic ray (CR) Galactic propagation parameters. In the diffusive reaccelaration (DR) model, the propagation parameters are shown to be Dxx ~ 4.5 x 10₂₈ - 6 x 10²⁸ cm² S-1, and VA ~ 28 - 42 km s-1. The impact of the uncertainties in the cosmic ray propagation model on dark matter limits is studied and the associated uncertainties of the 90% upper bound of the boost factor are found to be less than 30%.