Stability of the 2+2 fermionic system with point interactions
We give a lower bound on the ground state energy of a system of two fermions of one species interacting with two fermions of another species via point interactions. We show that there is a critical mass ratio m2 â‰ˆ 0.58 such that the system is stable, i.e., the energy is bounded from below, for mâˆˆ[m2,m2âˆ’1]. So far it was not known whether this 2 + 2 system exhibits a stable region at all or whether the formation of four-body bound states causes an unbounded spectrum for all mass ratios, similar to the Thomas effect. Our result gives further evidence for the stability of the more general N + M system.
21
3
Springer
application/pdf