  We show that the well-known \v{C}erenkov Effect contains new phenomena
arising from the quantum nature of charged particles. The \v{C}erenkov
transition amplitudes allow coupling between the charged particle and the
emitted photon through their orbital angular momentum (OAM) and spin, by
scattering into preferred angles and polarizations. Importantly, the spectral
response reveals a discontinuity immediately below a frequency cutoff that can
occur in the optical region. Specifically, with proper shaping of electron
beams (ebeams), we predict that the traditional \v{C}erenkov radiation angle
splits into two distinctive cones of photonic shockwaves. One of the shockwaves
can move along a backward cone, otherwise considered impossible for
\v{C}erenkov radiation in ordinary matter. Our findings are observable for
ebeams with realistic parameters, offering new applications including novel
quantum optics sources, and open a new realm for \v{C}erenkov detectors
involving the spin and orbital angular momentum of charged particles.
