An effective field theory approach to few particles in a trap.
Jimmy Rotureau (Arizona university-USA)
11h GANIL Guest House
The properties of strongly interacting Fermi gases have been the object of great interest in recent years. In situations where the interatomic scattering length a_2 is much larger than the effective range of the interaction r_0, few-atom systems serve as a testing ground for techniques developed for the ab-initio solution of few-nucleon systems.
We have applied the general principles of Effective Field Theory for the description of few-fermions systems trapped in a harmonic oscillator potential. The interaction between fermions is written as a controllable expansion consisting of contact interactions with an increasing number of derivatives. The no-core shell model formalism is used to solve the many-body Schroedinger equation at leading order (LO) and corrections beyond LO are treated in perturbation theory. We have also addressed the relationship between the two-body and many-body cutoffs needed for a consistent model space.
Results for the energies of the 3-fermions system at unitarity will be presented and shown to agree with known results. Results for systems with 3, 4 fermions for different values of a2/b (b being the trap length) and r0/b will also be presented. Future applications for nuclear systems will be also presented.
