INSTITUTO DE INVESTIGACIONES FISICAS DE MAR DEL PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Universal Deviations from the Wigner Threshold Law,
P. A. MACRI; R. O. BARRACHINA
Conferencia; 19th International IUPAP Conference on Few Body Problems in Physics; 2009
The International Union of Pure and Applied Physics
Few body systems where two particles have similar momenta are of particular interest in Atomic,Molecular, Nuclear and Particle Physics [1-4]. Since 60 years ago, the near threshold behavior of the corresponding cross sections is described by the Wigner threshold law (WTL). Although collisions in these energy regimes show many conspicuous effects -like resonances, cusps, dips and step structures- which are known to restrain the scope of the WTL, up to now there is no theoretical estimation of its range of applicability or even less how these e®ects modify its behavior. The importance of revealing these matters of low energy scattering are increasingly more pressing with the advance of modern atomic and molecular physics ¯elds such as Bose-Einstein condensation, atom interferometers and atomic clocks. Collisions at thresholds are experimentally tested now at unprecedentedly low energies. For example, ...