  The thermodynamics of the infinite-range Ising spin glass with p-spin
interactions in the presence of an external magnetic field h is investigated
analytically using the replica method. We give emphasis to the analysis of the
transition between the replica symmetric and the one-step replica symmetry
breaking regimes. In particular, we derive analytical conditions for the onset
of the continuous transition, as well as for the location of the tricritical
point at which the transition between those two regimes becomes discontinuous.
