  We investigate the macroscopic quantum tunneling of the attractive
Bose-Einstein condensate. Within the effective Lagrangian framework, we find
bounce solutions and explicitly calculate the decay rate of the condensate
trapped in a cylindrically symmetric potential. In particular, in the case
where the number of condensed bosons is slightly below a certain critical
number, we present a detailed analysis of the bounce solutions and discuss the
approximations employed in our calculations. The effects of finite temperatures
and the shape of the trapping potential are evaluated.

Condensed Matter