AMS-02 has reached the sensitivity to probe canonical thermal WIMPs by their
annihilation into antiprotons. Due to the high precision of the data,
uncertainties in the astrophysical background have become the most limiting
factor for indirect dark matter detection. In this work we systematically
quantify and -- where possible -- reduce uncertainties in the antiproton
background. We constrain the propagation of charged cosmic rays through the
combination of antiproton, B/C and positron data. Cross section uncertainties
are determined from a wide collection of accelerator data and are -- for the
first time ever -- fully taken into account. This allows us to robustly
constrain even subdominant dark matter signals through their spectral
properties. For a standard NFW dark matter profile we are able to exclude
thermal WIMPs with masses up to 570 GeV which annihilate into bottom quarks.
While we confirm a reported excess compatible with dark matter of mass around
80 GeV, its local (global) significance only reaches 2.2 sigma (1.1 sigma) in
our analysis.Comment: 38 pages + references, 14 figure
