0000000000677627
AUTHOR
Earle L. Lomon
Isobar width effects in the coupling of nucleon to isobar channels
The investigation of the effects of isobar coupling to two-nucleon channels has been extended to include additional physical features. A new code discretizes the mass distribution of the isobar widths and treats each mass as a separate channel. This allows the treatment of width in the presence of coupling by transition potentials, in addition to the previously permitted boundary coupling. It also produces the S-italic-matrix components required to describe the many-body final-state distributions. When indicated by the one-pion-exchange coupling strength new isobar channels are included. The new results for nucleon-nucleon scattering fit the data better, starting from more realistic models.…
Correlation of pp data with predictions of improved six-quark structure models.
Recent experimental data indicate a structure in \ensuremath{\Delta}${\ensuremath{\sigma}}_{L}$ corresponding to a pp mass of 2.7 GeV/${c}^{2}$, as earlier predicted for a six-quark $^{1}\mathrm{S}_{0}$ state by an R-matrix treatment of the cloudy-bag-model quark degrees of freedom interior to a coupled-isobar-channel system. The $^{1}\mathrm{S}_{0}$ model is improved to agree with 2\ensuremath{\pi} production data at 800 MeV laboratory energy. The resulting $^{1}\mathrm{S}_{0}$ partial wave and recently improved models of the background partial waves as well as older versions of the phase parameters predict experimental observables in the resonance region. The predicted width and inelastic…