Kimio Miura

ηb, Bc and a Hybrid Potential

We propose a hybrid potential, which is a Coulomb plus harmonic oscillator potential at short distances and increases linearly at long distances, and compute the heavy meson masses of various quarkonia with common parameter values. We obtain good agreement with experimental data for the cu, cd, cs, bu, bd, bs, cc and bb meson masses: We find the first solution that fits both horizontal and vertical spectra of heavy mesons with common parameter values. In particular, we are able to account for a recent observation, which may be attributable to η b , with a mass of 9300 ± 20 ± 20 MeV, which is much smaller than values predicted by many models and is difficult to account for with a small value of α s for bottomonium. We attempt to determine the vertical spectrum of B c mesons as accurately as possible.

Two-loop double-pole counter lagrangian

Abstract On the basis of the background field method, extended one-loop counterterm formulae are derived, and a method to get the two-loop double-pole counter lagrangian is given. As an example, the double-pole divergences of ξ 2 X 3 counterterms are obtained.