On search for a new light gauge boson from ${\pi }^0(\eta )\to \gamma +X$ decays in neutrino experiments

It is shown that a new light gauge boson $X$ which might be produced in the decays of pseudoscalar mesons ${\pi }^0(\eta )\to \gamma +X$ could be effectively searched for in neutrino experiments via the Primakoff effect, in the process of $X+Z\to {\pi }^0(\eta )+Z$ conversion in the external Coulomb field of a nucleus. An estimate of the $X\to {\pi }^0$ conversion rate for the NOMAD neutrino detector at CERN is given.