Study of the f0(1500)/f2(1565) production in the exclusive annihilation anti-n p --> pi+ pi+ pi- in flight

The spin-parity analysis of the n̄p⃗π+π+π- exclusive reaction in flight is presented. The main aim is to study the (π+π-) invariant mass spectrum in the region around 1500 MeV. The analysis was performed with a Breit-Wigner parametrization for all the resonant states and, for the scalar sector in the mass region below 1.2 GeV, by means of a K-matrix-like treatment. It clearly shows the need for two states, a scalar one (0++) with mass and width (1522±25) MeV and (108±33) MeV, and a tensorial one (2++) with mass (1575±18) MeV and width (119±24) MeV, respectively. In addition, the analysis requires the presence of a scalar state at (1280±55) MeV, (323±13) MeV broad, and of a second vectorial one, in addition to the ρ0(770) signal, with mass and width (1348±33) MeV and (275±10) MeV, respectively.