10^{26} s$, while for dark matter decaying to $W^+W^-$ with mass $m_{\chi}^{\rm dec}=200$ GeV, $\tau_0 \approx 7.5 \times 10^{27} s$. Here we note that $m_{\chi}^{\rm dec} = 2m_{\chi}$.

In the case of annihilation to heavy quarks, the very recent analysis of Ref. [@antiproton2] has updated antiproton constraints on WIMP annihilation to heavy quarks. Specifically, a thermal WIMP annihilating to heavy quarks is ruled out by current Fermi and PAMELA measurements up to approximately 30 GeV while AMS-02 should probe a thermal cross-section up to $\sim$200 GeV very soon. The antiproton flux is a very important indicator which is directly correlated to the production of heavier anti-nuclei. However, the coalescence momentum for [$\overline{\text{D}}~$]{}and [$^3\overline{\text{He}}~$]{}can float independently of such measurements and it is therefore not unreasonable that a [$\overline{\text{D}}~$]{}excess could be observed in-spite of an expected exclusion from antiprotons. For antihelium, an antiproton constraints are even less direct than the case of [$\overline{\text{D}}~$]{}due to the unconstrained coalescence momentum.

It is clear that the current generation of experiments is very unlikely to be sensitive to primary antihelium from dark matter annihilation. Future generation satellite born experiments using a GAPS(SAT) detector, as initially proposed in Ref. [@GAPS_first], could potentially be sensitive to WIMPs annihilating 