physics at accelerators Up: Astrophysical
Limits Previous: Neutrino
A neutrino electromagnetic dipole or transition moment would lead to an
enhanced rate for the plasma decay process
which dominates the neutrino cooling of low-mass stars, notably of low-mass
red giants before the helium flash. This would delay helium ignition, in
contradiction with globular-cluster data, leading to
the Bohr magneton. This limit applies if ,
where threshold effects become important. Transition moments can be constrained
by searching for radiative decays .
is essentially massless the decay rate is
the transition moment. If neutrinos obey Eq. ()
the phase-space factor
renders the radiative decay limits from reactor, accelerator, solar, supernova,
and cosmic background neutrinos less restrictive than Eq. ().