A Possible Event of Charmed Particle Decay via the (Weak) Neutral Current According to a Scheme M(c) --> e+ e- Hadrons

In a stack of nuclear emulsion irradiated by 200 Gev/c {pi}{sup -}-mesons at FNAL, we have made a search for new short-lived particles by tracing all secondary tracks from the star in a cone of 0 < 0,1 rad up to the distance of 1 mm. The sample of stars consisted of 350 {pi}{sup -} N- and 250 {pi}{sup -} A-interactions. They have found one peculiar event. Among {pi}{sup -} A-interactions there is star of type 21 + 6 + 23 p in which one secondary prong (0{sub L} = 4,6{sup o}) gives at the distance 42 {micro} from the center of the star very narrow jet of the type 0 + 0 + 5p. Measurements of the angles, momenta and ionizations of the particles from this jet allowed to identify two particles as electrons. A total momentum of all five particles is about 9 Gev/c. Probability to observe such narrow jet due to an ordinary nuclear interaction on nucleon or coherent reaction on nucleus with production of five charged particles (including e{sup +}e{sup -} pair) at 10-20 Gev/c is less than 0,5.10{sup -6}, and by this reason they treat it as a decay of new short-lived particle. Estimation of the mass of this particle is in agreement with the value expected for the charmed particle. its life time is {approx} (2-3).10{sup -14} sec. Two electrons appearing in the decay of this particle allow one to interpret it as a possible example of the charmed particle decay due to (weak) neutral currents according to the scheme M{sub 0} {yields} e{sup +}e{sup -} + hadrons