  We consider for the first time R-parity violating interactions of the Minimal
Standard Supersymmetric Model involving neutrinos and quarks (``flavor changing
neutral currents'', FCNC's) in the infall stage of stellar collapse. Our
considerations extend to other kinds of flavor changing neutrino reactions as
well. We examine non-forward neutrino scattering processes on heavy nuclei and
free nucleons in the supernova core. This investigation has led to four
principal original discoveries/products: (1) first calculation of neutrino
flavor changing cross sections for spin one half (e.g. free nucleon) and spin
zero nuclear targets; (2) discovery of nuclear mass number squared (A squared)
coherent amplification of neutrino-quark FCNC's; (3) analysis of FCNC-induced
alteration of electron capture and weak/nuclear equilibrium in the collapsing
core; and (4) generalization of the calculated cross sections (mentioned in 1)
for the case of hot heavy nuclei to be used in collapse/supernova and neutrino
transport simulations. The scattering processes that we consider allow electron
neutrinos to change flavor during core collapse, thereby opening holes in the
electron neutrino sea, which allows electron capture to proceed and results in
a lower core electron fraction. A lower electron fraction implies a lower
homologous core mass, a lower shock energy, and a greater nuclear
photo-disintegration burden for the shock. In addition, unlike the standard
supernova model, the core now could have net muon and/or tau lepton numbers.
These effects could be significant even for supersymmetric couplings below
current experimental bounds.
