SEARCH ON e+ - e- PAIR AND OBSERVATION OF A NEW LIGHT NEUTRAL BOSON

We present a unified description of e(+) e(-) dilepton production in heavy ion collisions at relativistic (3.7A GeV) and ultrarelativistic (200A GeV) energies. From the interactions of [C-12 and Ne-22] at 3.7A GeV and S-32 at 200A GeV with nuclear emulsion, 134 e(+) e(-) pairs are observed. The differential distribution of the energy asymmetry of pairs is compared to a background observation at Bristol. The events are consistent in a way that, they scale well in a single curve of exponential decay. This ensures correct asymptotics and provides a unified description of mesonic decay. The existence of light neutral boson of mass (1.55 +/- 0.14 MeV/c(2)) is questionable, because the candidate peak is seen in the invariant mass spectrum of its decay into e(+) e(-) pairs. The data seem to suggest the production and subsequent decay of short lived neutral boson with lifetime of the order of 10(-16) S.