  Metastable excited states ${}^3P_2, {}^3P_0$ of heavy alkaline earth atoms of
even isotopes are studied for parity violating (PV) effects in radiative
emission of neutrino pair (RENP). PV terms arise from interference between two
diagrams containing neutrino pair emission of valence spin current and nuclear
electroweak charge density proportional to the number of neutrons in nucleus.
This mechanism gives large PV effects, since it does not suffer from the
suppression of 1/(electron mass) usually present for non-relativistic atomic
electrons. A controllable magnetic field is crucial to identify RENP process by
measuring PV observables. Results of PV asymmetries under the magnetic field
reversal and the photon circular polarization reversal are presented for an
example of Yb atom.
