Running mass of the rho0 meson's implication for the dilepton mass spectrum and the mu+ mu- / e+ e- branching ratio in the K+ ---> pi+ lepton+ lepton- decays

@article{Lichard1999RunningMO,
  title={Running mass of the rho0 meson's implication for the dilepton mass spectrum and the mu+ mu- / e+ e- branching ratio in the K+ ---> pi+ lepton+ lepton- decays},
  author={Peter Lichard},
  journal={Physical Review D},
  year={1999},
  pages={053007}
}
  • P. Lichard
  • Published 1 March 1999
  • Physics
  • Physical Review D
We make an attempt to resolve the discrepancy of the observed e+e- mass spectrum in the K+ --> pi+e+e- decay with that predicted by meson dominance. To this end we investigate the properties of the rho0 propagator. We use dispersion relations to evaluate the running mass squared m_rho^2(t) of the rho0 resonance without adjustable parameters. To improve the convergence of the dispersion integral, the momentum dependence of strong vertices is taken from the flux-tube-breaking model of Kokoski and…