Evidence for the dominance of an IGJPC = 0+0++ resonance in anti pn →2π+3π- annihilation at rest

The reanalysis of 1496 anti pn→2π+3π- annihilations at rest of the Rome-Syracuse collaboration has shown that this reaction is dominated by the production of a 4π resonance with M=1386 MeV/c2, Γ=310 MeV/c2 and quantum numbers IGJPC=0+0++. This result is in disagreement with a previous analysis, which, assuming ρρ decay, found preference for JP=2+. The name proposed for the resonance is S0(1390). The dominant decays of this resonance are into ρρ and σσ, σ being the I=0 S-wave 2π interaction. The upper limit for other decays is estimated to be 20%. The ρ0ρ0-σσ interference reproduces the distributions of the like pion combinations 2π+, 2π- and 3π-. This indicates that the interference between resonance and daughters could be one of the dynamical mechanisms which generate the Bose-Einstein correlation. Furthermore, an evaluation of the five-prong frequencies is reported. Using these values, the total frequency of the annihilation anti pn→S0(1390)π- is estimated to be between 15% and 20%. (orig.)