ar X iv : h ep - p h / 99 08 37 7 v 2 3 S ep 1 99 9 Matching Heavy Particle Approach to Relativistic Theory

ar X iv : h ep - p h / 99 08 37 7 v 1 1 7 A ug 1 99 9 Matching Heavy Particle Approach to Relativistic Theory

On the simple model of interacting massless and heavy scalar fields it is demonstrated that the technique of heavy baryon chiral perturbation theory reproduces the results of relativistic theory. Explicit calculations are performed for diagrams including two-loops.

ar X iv : h ep - p h / 98 05 37 5 v 1 1 9 M ay 1 99 8 Production of bound μ + μ − - systems in relativistic heavy ion collisions

ar X iv : h ep - p h / 99 10 26 0 v 1 7 O ct 1 99 9 Is Heavy Baryon Approach Necessary ?

On the simple model of interacting massless pseudoscalar and heavy fermion fields it is demonstrated that using appropriately chosen renormalization condition one can respect power counting within the relativistic theory without applying the technique of heavy baryon approach. Explicit calculations are performed for diagrams including two-loops. It is argued that the introduction of the heavy b...

X iv : h ep - t h / 93 03 08 6 v 1 1 5 M ar 1 99 3 Zero - curvature condition in two dimensions . Relativistic particle models and finite W - transformations

A relation between an Sp(2M) gauge particle model and the zero-curvature condition in a two-dimensional gauge theory is presented. For the Sp(4) case we construct finite W-transformations.

ar X iv : h ep - p h / 99 05 54 3 v 1 2 9 M ay 1 99 9 Effective Field Theory Approach to Pionium

The various dynamical scales below the pion mass involved in π + π − atoms are sequentially integrated out using non-relativistic effective field theory techniques. This allows us to systematically organise the corrections to the energy levels and decay width. We present our results in terms of a single unknown constant which may be obtained by matching to the Chiral Lagrangian with electromagn...