Investigation of the n n Λ bound state in pionless effective theory
Abstract
The possibility of an n n Λ bound state is investigated in the framework of pionless effective field theory at leading order. A system of coupled integral equations are constructed in the spinisospin basis, of which numerical solutions are investigated. In particular, we make use of the limit cycle behavior, i.e., cyclic singularities of coupled integral equations of the system, which would be associated with the formation of a threebody bound state, the socalled Efimov state, in the unitary limit. Furthermore, we find that, when the sharp momentum cutoff introduced in the integral equations is taken to be significantly larger than the hard scale of the effective theory, the coupling of a threebody contact interaction becomes cyclically singular indicating the onset of an Efimovlike bound state formation. However, the paucity of empirical information to determine the parameters of the theory precludes a definitive conclusion on the existence of such a bound state. As a simple test of the feasibility of the n n Λ bound system in nature, we explore the cutoff dependence of the theory, and uncertainties of the present study are discussed as well.
 Publication:

Physical Review C
 Pub Date:
 August 2015
 DOI:
 10.1103/PhysRevC.92.024325
 arXiv:
 arXiv:1507.01260
 Bibcode:
 2015PhRvC..92b4325A
 Keywords:

 11.10.Hi;
 13.75.Ev;
 21.45.v;
 21.80.+a;
 Renormalization group evolution of parameters;
 Hyperonnucleon interactions;
 Fewbody systems;
 Hypernuclei;
 Nuclear Theory;
 High Energy Physics  Phenomenology
 EPrint:
 10 pages, 5 figures, REVTeX, revised version