Each of the potential signals from a black hole-neutron star merger should
contain an imprint of the neutron star equation of state: gravitational waves
via its effect on tidal disruption, the kilonova via its effect on the ejecta,
and the gamma ray burst via its effect on the remnant disk. These effects have
been studied by numerical simulations and quantified by semi-analytic formulae.
However, most of the simulations on which these formulae are based use
equations of state without finite temperature and composition-dependent nuclear
physics. In this paper, we simulate black hole-neutron star mergers varying
both the neutron star mass and the equation of state, using three
finite-temperature nuclear models of varying stiffness. Our simulations largely
vindicate formulae for ejecta properties but do not find the expected
dependence of disk mass on neutron star compaction. We track the early
evolution of the accretion disk, largely driven by shocking and fallback
inflow, and do find notable equation of state effects on the structure of this
early-time, neutrino-bright disk.