2,350 research outputs found
Antiproton-proton partial-wave analysis below 925 MeV/c
A partial-wave analysis of all antiproton-proton scattering data below 925
MeV/c antiproton laboratory momentum is presented. The method used is adapted
from the Nijmegen phase-shift analyses of pp and np scattering data. The
Nijmegen 1993 antiproton-proton database, consisting of 3646 antiproton-proton
scattering data, is presented and discussed. The best fit to this database
results in chi^2_min/Ndata = 1.043. The pseudovector coupling constant of the
charged pion to nucleons is determined to be (f_c)^2 = 0.0732(11) at the pion
pole, where the error is statistical.Comment: Report THEF-NYM 93.02 42 pages REVTeX, 7 separate postscript figures
appended. Accepted for publication in Phys. Rev.
The nucleon-sigma coupling constant in QCD Sum Rules
The external-field QCD Sum Rules method is used to evaluate the coupling
constant of the light isoscalar-scalar meson (``'' or \epsilon) to the
nucleon. The contributions that come from the excited nucleon states and the
response of the continuum threshold to the external field are calculated. The
obtained value of the coupling constant is compatible with the large value
required in one-boson exchange potential models of the two-nucleon interaction.Comment: 11 pages, 4 figure
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