Europhys. Lett.
Volume 75, Number 4, August 2006
Page(s) 555 - 561
Section Nuclear physics
Published online 07 July 2006
Europhys. Lett., 75 (4), pp. 555-561 (2006)
DOI: 10.1209/epl/i2006-10141-6

Four-boson scale near a Feshbach resonance

M. T. Yamashita1, Lauro Tomio2, A. Delfino3 and T. Frederico4

1  Universidade Estadual Paulista - 18409-010, Itapeva, SP, Brazil
2  Instituto de Física Teórica, Universidade Estadual Paulista 01405-900, São Paulo, SP, Brazil
3  Instituto de Física, Universidade Federal Fluminense 24210-900, Niterói, RJ, Brazil
4  Departamento de Física, Instituto Tecnológico de Aeronáutica Centro Técnico Aeroespacial - 12228-900 São José dos Campos, SP, Brazil

received 8 April 2006; accepted in final form 20 June 2006
published online 7 July 2006

We show that an independent four-body momentum scale $\mu_{(4)}$ drives the tetramer binding energy for fixed trimer energy (or three-body scale $\mu_{(3)}$) and large scattering length (a). The three- and four-body forces from the one-channel reduction of the atomic interaction near a Feshbach resonance disentangle $\mu_{(4)}$ and $\mu_{(3)}$. The four-body independent scale is also manifested through a family of Tjon lines, with slope given by $\mu_{(4)}/\mu_{(3)}$ for a-1=0. There is the possibility of a new renormalization group limit cycle due to the new scale.

21.45.+v - Few-body systems.
36.40.-c - Atomic and molecular clusters.
05.10.Cc - Renormalization group methods.

© EDP Sciences 2006