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. 
S.N. Gninenko and N.V. Krasnikov