Narrow Results

Partial K-x ray production cross sections of dysprosium, erbium and lutetium by proton and ³He-ion impact have been measured over the incident energy range of 3-40 MeV/amu. It is found that the measured ionization cross sections become larger in comparison with the prediction of PWBA theory and agree well with the ECPSSR theory in the wide energy region. This fact means that relativistic effect of inner-shell electrons is the most predominant among many effects such as the energy loss and the Coulomb deflection of the projectile and also the effects of polarization and increased binding energy of orbital electrons in the perturbed stationary states.

The energy-loss effect of the projectile for direct inner-shell ionization cross sections by charged-particle impact has been examined. The relativistic and nonrelativistic calculations for K-shell ionization with and without the energy-loss effect are made in the plane-wave Born approximation and compared with the Brandt-Lapicki theory for the corrections of the relativistic and energy-loss effect. It is demonstrated that the Brandt-Lapicki method gives a good approximation to both relativistic and nonrelativistic cross sections, which implicitly take into account the energy-loss effect. However, the use of the Brandt-Lapicki relativistic correction method in the nonrelativistic theory with the exact integration limits for energy and momentum transfer overestimates the relativistic calculations for low-energy projectiles. This indicates that the Brandt-Lapicki method for correction of the electronic relativistic effect should be used only with their energy-loss correction method.

Relativistic effects in two photon decay of 0^-+ quarkonium are investigated with a relativistic phenomenological approach. Comparing with the non-relativistic approximation, the relativistic phenomenological approach gives corrections coming from three sources: relative momentum distribution, relative energy distribution and description of quark spinors in the meson. These relativistic effects are studied in detail for and systems.