The presence of extra P11 resonances in Zagreb analysis since 1995 A. Švarc, S. Ceci and B. Zauner Rudjer Bošković Institute Zagreb

Definition of the Zagreb model CMU-LBL formalism

Formalism:

GENERAL AGREEMENT the number of resonances directly corresponds to the number of poles of the Green function in the CMU_LBL formalism PROBLEM: resonance identification

The input for the Zagreb model 1. pion elastic channel : partial T-matrices (KH-80+SM85) 2. eta-production channel: DATA BASE 3. number of Green function poles per partial wave

The criterion of acceptance the best chi-square fit general acceptability

Number of Green function poles required by the Zagreb PWA (possible solutions) S11: three poles in the Green function (the same as PDG) P11: a. three poles in the Green function b. four poles in the Green function

The model with four poles Batinic et al. Physica Scripta 58 (1998) 15 black line The model with three poles Batinic et al. Phys. Rev C51 (1995) 231 red line

The best obtained chi-square/data point three poles model: four poles model: 1.301

Obtained P11 T-matrices COMPARISON

The resonance criterion (T-matrix pole)

Resonance parameters for 3 Green function poles

Resonance parameters for 4 Green function poles

CONCLUSIONS 1. We obtain two solutions, with three and four poles respectively, which to the precision of the input data equally well reproduce 2. The three resonant solution does not give any significan branching ratio to the and channels channelso we prefere a four resonance solution 3. We do not claim that such a three resonant solution does not exist, we simply claim that at the present moment we have no means to find it

The solution We are developing the general purposse code (GPC)

The flow chart