Lowest open channels, bound states, and narrow resonances of dipositronium

. at om - p h ] 2 5 Se p 20 03 LOWEST OPEN CHANNELS , BOUND STATES , AND NARROWRES - ONANCES OF DIPOSITRONIUM

The constraints imposed by symmetry on the open channels of dipositronium has been studied, and the symmetry-adapted lowest open channel of each quantum state has been identified. Based on this study, the existence of two more 0 + bound states has been theoretically confirmed, and a 0 + narrow resonance has been predicted. A variational calculation has been performed to evaluate the critical st...

Bound states at lowest order in ~

Bound states poles in scattering amplitudes are generated by the divergence of the perturbative series due to enhanced Coulomb scattering near thresholds. This suggests to organize bound state calculations according to an expansion in ~, i.e., in the number of loops. I study QED and QCD bound states at lowest order in ~, which are analogous to usual Born amplitudes. The absence of loops allows ...

Calculation of bound states and resonances in perturbed Coulomb models

We calculate accurate bound states and resonances of two interesting perturbed Coulomb models by means of the Riccati-Padé method. This approach is based on a rational approximation to a modified logarithmic derivative of the eigenfunction and produces sequences of roots of Hankel determinants that converge towards the eigenvalues of the equation.

Orbiting Resonances and Bound States in Molecular Scattering

A family of orbiting resonances in molecular scattering is globally described by using a single pole moving in the complex angular momentum plane. The extrapolation of this pole at negative energies gives the location of the bound states. Then a single pole trajectory, that connects a rotational band of bound states and orbiting resonances, is obtained. These complex angular momentum singularit...

Scattering resonances and bound states for strongly interacting Rydberg polaritons