Revisiting the limits on dark matter annihilation cross-section and decay lifetime in light of electron and positron fluxes

Abstract We revisit the upper bound on the annihilation cross-section, 〈 σv 〉 of a stable dark matter (DM) of mass 500-10 14 GeV by considering five different channels: W + W - , bb̅ , μ + μ - , τ + - , and e + e - . We use the observed electron and positron fluxes from CALET, DAMPE, HESS, positron flux from AMS-02, and gamma-ray flux from HAWC, GRAPES-3, CASA-MIA to constrain the annihilation cross-section. We also consider unstable DM of mass 10 3 -10 16 GeV decaying to W + W - , bb̅ , μ + μ - , τ + τ - , and e + e - and derive the corresponding lower bound on the DM lifetime, τ DM . We find that the latest AMS-02 data provide the most stringent constraints on 〈 σv 〉 for DM masses below 2 TeV, while HESS yields the strongest limits for M DM ≳ 2 TeV. The HESS gives a much more stringent limit on the DM lifetime, excluding τ DM → μ + μ - ≲ 𝒪(10 30 ) s for a 10 TeV mass of DM. The limits on 〈 σv 〉 derived from the e + e - flux are competitive with those from γ -ray and neutrino observations for DM masses in the range 10 5 –10 11 GeV, and become the most stringent beyond this range. For decaying DM, the e + e - flux provides the strongest constraints on the DM lifetime over the mass range 10 3 –10 9 GeV.