Determination of the pion-nucleon coupling constant

Publisher Website
Google Scholar
Abstract
Forward dispersion relations are used to determine the pion-nucleon coupling constant and S-wave scattering lengths using a least-squares fit with additional parameters introduced to take account of the uncertainties in the calculation of dispersion integrals. It is observed that the parameters are very much dependent on the data sets used, f2 varying from 0.0707 to 0.0807 for fits using four or more data sets. Results obtained using the input of all data sets are f2=(76.9+or-2.0)*10-3, a1-a3=(271.6+or-11.5)*10-3, a1+2a3=(25.8+or-10.4)*10-3, while the results using all data below 300 MeV are f2=(80.7+or-3.3)*10-3, a1-a3=(282.8+or-25.6)*10-3, a1+2a3=(-1.8+or-28.5)*10-3.