We derive 95 % CL lower limits on the lifetime of decaying dark matter in the channels Z \nu , W \ell and h \nu using measurements of the cosmic-ray antiproton flux by the PAMELA experiment .
Performing a scan over the allowed range of cosmic-ray propagation parameters we find lifetime limits in the range of 8 \times 10 ^ { 28 } s to 5 \times 10 ^ { 25 } s for dark matter masses from roughly 100 GeV to 10 TeV .
We apply these limits to the well-motivated case of gravitino dark matter in scenarios with bilinear violation of R -parity and find a similar range of lifetime limits for the same range of gravitino masses .
Converting the lifetime limits to constraints on the size of the R -parity violating coupling we find upper limits in the range of 10 ^ { -8 } to 8 \times 10 ^ { -13 } .