  Antideuterons are a potential messenger for dark matter annihilation or decay
in our own galaxy, with very low backgrounds expected from astrophysical
processes. The standard coalescence model of antideuteron formation, while
simple to implement, is shown to be under considerable strain by recent data
from the LHC. We suggest a new empirically based model, with only one free
parameter, which is better able to cope with these data, and we explore the
consequences of the model for dark matter searches.
