Role of theN*(1535)resonance and theπ−p→

Evidence ofN*(1535)resonance contribution in thepn→dϕ

“…For the πN → φN reaction, although the total cross sections can be reproduced by the t-channel ρ exchange and/or subthreshold nucleon pole contributions [11,28], these contributions are very sensitive to the choice of off-shell form factors for the t-channel ρ exchange and the g N N φ couplings and can be reduced by orders of magnitude within uncertainties of these in- gredients. Alternative mechanisms [15,29] with large N * (1535) contribution can reproduce data perfectly. For the γp → φp reaction, a much larger OZI rule violation for φ-meson production was suggested [30,31,32] with no indications for s-channel resonances above threshold [32].…”

The width of the ω meson in the nuclear medium

“…Despite the considerable cancellation between the g 1 and g 2 terms, this value is still much larger than the absolute value of the coupling derived in [93]. Consequently, the contribution of the S 11 (1535) to the ω width turns out to be about 15 times larger in [49] than that one would obtain using the coupling derived in [93]. This is just a simple example trying to show that the couplings of some resonances to ωN states at threshold might not be very well constrained experimentally due to interferences between various a priori unknown resonant terms and background contributions.…”

“…One can consider vector-baryon and pseudoscalar-baryon components together, as done in [71], but the mixing is small and the different dynamically generated states basically keep their original identity. Yet, it is simple to determine the coupling of one particular pseudoscalar-baryon resonance to a vector-baryon channel using chiral unitary methods and vector meson dynamics, as done in [93]. Neglecting terms of order O ( q/2M ) 2 , the coupling of the N * (1535) to ωN states was found to be given by…”

“…The dynamical model of Ref. [93] determined the value g N * N ω = 0.02 + i 0.28. It is straightforward to show that, neglecting terms of O ( q/2M ) 2 , the Lagrangian employed in Ref.…”

Correlations ofπNpartial waves for multireaction analyses

“…Furthermore, with the same hadronic amplitude, pion-and η photoproduction could be predicted [42,43]. The role of chiral dynamics in S-wave baryonic resonances, including fits to πN partial waves, has been studied by many groups [44][45][46][47][48][49][50][51][52][53]. Other examples, in which fits to πN partial waves are crucial to investigate chiral dynamics and to test models, include the D 33 partial wave [54][55][56][57] and a family of J P = 1/2 − , 3/2 − states [52,53,58].…”