Experimental limits on the mass and decay lifetime of γsubμ

The nonobservation of photon-induced e+e- pairs pointing in the neutrino beam direction in large bubble chambers would allow one to set an upper limit on the product msub(γsub(μ))GAMMAsup(CM) for muon-type neutrinos, where msub(γsub(μ)) is the mass and GAMMAsup(CM) is the intrinsic partial decay width in sec-1 for γsub(μ)→γ+X. In the theory of Eliezer and Ross where GAMMAsup(LAB) approximately 0.8x10-19(m2sub(γsub(μ))-m2sub(γsub(e)))/hEsub(γ)/2π, this implies an upper limit on msub(γsub(μ)) considerably smaller than the present upper limit, and a large lower limit on the lifetime tausub(γsub(μ)). (Auth.)