Prof. Pedro Gonzalez (University of Valencia)
From a Faddeev calculation for the pion-(Delta rho)(N(1675)) system, performed with the Fixed Center Approximation within a Chiral Unitary framework, we show the plausible existence of three dynamically generated I (JP) = 3/2 (5/2+) baryon states below 2.3 GeV whereas only two resonances, Delta(5/2+) (1905) (∗∗∗∗) and Delta(5/2+) (2000) (∗∗), are cataloged in the Particle Data Book Review. However, a careful look at Delta(2000)(5/2+) (∗∗), shows that its nominal mass is in fact estimated from the masses (1724±61), (1752±32) and (2200±125) respectively extracted from three independent analyses of different character[2,3,4]. Moreover a recent new data analysis has reported a Delta(5/2+)with a pole position at 1738 MeV. Our results give quantitative theoretical support to the existence of two distinctive resonances, Delta(5/2+)(∼1740) and Delta(5/2+)(∼2200). We propose that these two resonances should be cataloged instead of Delta(5/2+)(2000). This proposal gets further support from the possible assignment of the other calculated baryon states in the I = 1/2, 3/2 and spin-parity JP =1/2+, 3/2+ sectors to known baryonic resonances. In particular the poorly established Delta(1/2+) (1750)(∗) may be naturally interpreted as a pion-N(1/2-)(1650) bound state. , K. Nakamura et al., J. Phys. G 37, 075021 (2010). , D.M. Manley and E.M. Saleski, Phys. Rev. D 45, 4002 (1992). ,T. P. Vrana, S. A. Dytman and T.-S. H. Lee, Phys. Rep. 328, 181 (2000). ,R.E. Cutkosky, C.P. Forsyth, J.B. Babcock, R.L. Kelly, and R.E. Hendrick, Proceedings of the IV International Conference on Baryon Resonances (Baryon 1980), edited by N. Isgur, Toronto 1980. ,N. Suzuki et al. (EBAC), Phys. Rev. Lett. 104, 042302 (2010).
Dr Ju Jun Xie (IFIC, University of Valencia)