Recently, Diakonov and Petrov have derived a formalism in the Relativistic Mean Field Approximation allowing one to derive the 3-, 5-, 7-, . . . quark wavefunctions for the octet, decuplet and antidecuplet. They have used this formalism and many strong approximations in order to estimate the exotic Θ width. The latter has been estimated to ∼ 4 MeV. Besides they obtained that the 5-quark compone...

Relativistic corrections beyond the simple one-electron mass–velocity–Darwin (MVD1) approximation to the ground-state electronic energy of H2S are determined at over 250 geometries. The corrections considered include the two-electron Darwin, the Gaunt and Breit corrections, and the one-electron Lamb shift. Fitted correction surfaces are constructed and used with an accurate ab initio nonrelativ...

Two-loop contributions to the electromagnetic form factors are calculated in the kinematic regime close to the fermion-antifermion threshold. The results are presented in an expansion in the velocity of the fermions in the c.m. frame up to next-to-next-to leading order in. The existence of a new Coulomb singularity logarithmic in , which is closely related to the O(2 ln) corrections known from ...

The universal curve σ/A of nuclear photoabsorption is investigated within a Fermi gas model of nuclear matter. An energy range from pion threshold up to 400 MeV is considered. The interactions between nu-cleon, pion, ∆-isobar and photon are considered in the non-relativistic approximation with corrections of the order 1/M taken into account with respect to proton mass. Analytical expressions ar...