  Despite their inextricable quantum mechanical nature, events at a high energy
particle collider experiment typically have very few unambiguous quantum
signatures, due the type of data and the manner in which they are collected. We
present a general analysis of one feature of quantum mechanics, interference
between two orthogonal states on Hilbert space, projected onto the basis of
states that span a collider experiment observable space. Identification of
quantum interference can be considered as a binary discrimination between a
pure state and a mixed state, and we introduce several statistical measures
that quantify the amplitude of interference in a pure state with respect to a
mixed state that exhibits no interference. Two explicit examples from particle
physics are provided to demonstrate features of the general formalism.
