Case in favor of the N*(1700)(3/2-)

Abstract

Using an interaction extracted from the local hidden-gauge Lagrangians, which brings together vector and pseudoscalar mesons, and the coupled channels ρN (s wave), πN (d wave), πΔ (s wave), and πΔ (d wave), we look in the region of √s=1400-1850 MeV and find two resonances dynamically generated by the interaction of these channels, which are naturally associated to N*(1520)(3/2-) and N *(1700)(3/2-). N*(1700)(3/2 -) appears neatly as a pole in the complex plane. The free parameters of the theory are chosen to fit the πN (d-wave) data. Both the real and imaginary parts of the πN amplitude vanish in our approach in the vicinity of this resonance, which is similar to what happens in experimental determinations and which makes this signal very weak in this channel. This feature could explain why this resonance does not show up in some experimental analyses, but the situation is analogous to that of the f0(980) resonance, the second scalar meson after σ[f0(500)] in the ππ(d-wave) amplitude. The unitary coupled channel approach followed here, in connection with the experimental data, leads automatically to a pole in the 1700-MeV region and makes this second 3/2- resonance unavoidable. © 2013 American Physical Society.