Tracer particles coupled to an interacting boson gas

Structure Functions in an Interacting Boson System*

3m (k) = dw d~S(k ,.,) for a system of Bosons of mass m at zero temperature and density n to the first approximation beyond the Bogoliubov (zeroth) approximation. The two-body interaction u is characterized by the s-wave scatteringlength and is taken to be a constant in k-space. The small dimensionless parameter g = 4irams 0, where s0 = (4iran) 1/2/m is the phonon speed in the zeroth approximat...

A nonextensive approach to Bose-Einstein condensation of trapped interacting boson gas

In the Bose-Einstein condensation of interacting atoms or molecules such as Rb, Na and Li, the theoretical understanding of the transition temperature is not always obvious due to the interactions or zero point energy which cannot be exactly taken into account. The S-wave collision model fails sometimes to account for the condensation temperatures. In this work, we look at the problem within th...

Ballistic Motion of a Tracer Particle Coupled to a Bose gas

We study the motion of a heavy tracer particle weakly coupled to a dense interacting Bose gas exhibiting Bose-Einstein condensation. In the so-called mean-field limit, the dynamics of this system approaches one determined by nonlinear Hamiltonian evolution equations. We derive the effective dynamics of the tracer particle, which is described by a non-linear integro-differential equation with me...

Quasidynamical symmetry in an interacting boson model phase transition.

The apparent persistence of symmetry in the face of strong symmetry-breaking interactions is examined in a many-boson model. The model exhibits a transition between two phases associated with U(5) and O(6) symmetries, respectively, as the value of a control parameter progresses from 0 to 1. The remarkable fact is that, in spite of strong mixing of the symmetries for intermediate values of the c...

Expansion of an Interacting Boson Condensate: the Role of Dimensionality