Low-energy pion-nucleon scattering
نویسندگان
چکیده
An analysis of low-energy charged pion-nucleon data from recent pp experiments is presented. From the scattering lengths and the Goldberger-Miyazawa-Oehme ~GMO! sum rule we find a value of the pion-nucleon coupling constant of f 50.075660.0007. We also find, contrary to most previous analyses, that the scattering volumes for the P31 and P13 partial waves are equal, within errors, corresponding to a symmetry found in the Hamiltonian of many theories. For the potential models used, the amplitudes are extrapolated into the subthreshold region to estimate the value of the S term. Off-shell amplitudes are also provided. @S0556-2813~98!01302-8#
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تاریخ انتشار 1998