New Result for the Pion-Nucleon Sigma Term from an Updated VPI/GW Pion-Nucleon Partial-Wave and Dispersion Relation Analysis
/ Authors
M. Pavan, R. Arndt, I. Strakovsky, R. C. F. Science, M.I.T., Cambridge, MA Dept. of Physics, V.P.I., Blacksburg, V. D. O. Physics
and 3 more authors
/ Abstract
A new result for the nucleon sigma term from an updated pion-nucleon partial-wave and dispersion relation analysis of the Virginia Polytechnic Institute (now George Washington University) group is discussed. Using a method similar to that of Gasser, Leutwyler, Locher, and Sainio, we obtain Sigma=90 +/- 8 MeV (preliminary), in disagreement with the canonical result 64 +/- 8 MeV, but consistent with expectations based on new information on the $\pi$NN coupling constant, pionic atoms, and the Delta resonance width.
Journal: arXiv: Nuclear Theory