Physicists have contributed, and are presently contributing, a lot to neuroscience. Essentially none of this, however, relates to "particle/quantum physics." Even "normal" quantum mechanics, and certainly anything related to particle physics, is irrelevant to how neurons function, interact, and given rise to complex phenomena, except in the trivial sense of the chemical bonds making up molecules being governed by quantum mechanics. The operation of neurons is controlled by the fascinating interplay between statistical mechanics and electrostatics that gives rise to propagating voltage pulses, for example, something physicists contributed to in terms of both theory and measurement. In more contemporary work, one figures out how, e.g., networks of neurons can recognize things like shapes in a visual field by considering interacting networks of excitable objects. (Both of these are over-simplifications, of course.) Phil Nelson's "Biological Physics" is a good place to get a little glimpse of neurons and physics.
I very strongly caution against making the mistake of thinking "quantum mechanics is mysterious, the brain is mysterious, therefore quantum mechanics must be relevant to consciousness!" It leads to all sorts of nonsense that's both bad physics (imagining quantum coherence in warm, dense materials) and bad biology.
Finally, if you'd like to read good things about the topic of free will, I recommend Daniel Dennett's work.