8 research outputs found
Mesonic cloud contribution to the nucleon and delta masses
Pion-nucleon elastic scattering in the dominant channel is examined
in the model in which the interaction is of the form . New expressions are found for the elastic pion-nucleon
scattering amplitude which differ from existing formula both in the kinematics
and in the treatment of the renormalization of the nucleon mass and coupling
constant. Fitting the model to the phase shifts in the channel does
not uniquely fix the parameters of the model. The cutoff for the pion-nucleon
form factor is found to lie in the range MeV/c. The masses
of the nucleon and the which would arise if there were no coupling to
mesons are found to be MeV and MeV. The difference in these bare masses, a quantity which would
be accounted for by a residual gluon interaction, is found to be MeV.Comment: 26 pages, 9 figures, significant rewrit
SEARCH FOR LIGHT NEUTRAL HIGGS PARTICLES PRODUCED IN Z0 DECAYS
A search for the neutral Higgs boson in Z0-decays has been performed using the DELPHI detector at the Large Electron Positron collider (LEP) at CERN. We looked for the decay of Z0 into a neutral Higgs particle and a pair of fermions. No events fulfilled the criteria for H0-production. Our results, which are based on an integrated luminosity of 530 nb-1, exclude a minimal Standard Model Higgs boson with a mass in the range 210 MeV/c2 to 14 GeV/c2 at 95% confidence level.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe