$$A=4-7$$ $$\varXi $$ hypernuclei based on interactions from chiral effective field theory

Abstract

We investigate the existence of bound $$\varXi $$ Ξ states in systems with $$A=4-7$$ A = 4 - 7 baryons using the Jacobi NCSM approach in combination with chiral NN and $$\varXi $$ Ξ N interactions. We find three shallow bound states for the NNN$$\varXi $$ Ξ system (with $$(J^\pi ,T)=(1^+,0)$$ ( J π , T ) = ( 1 + , 0 ) , $$(0^+,1)$$ ( 0 + , 1 ) and $$(1^+,1)$$ ( 1 + , 1 ) ) with quite similar binding energies. The $$^5_{\varXi }\mathrm {H}(\frac{1}{2}^+,\frac{1}{2})$$ Ξ 5 H ( 1 2 + , 1 2 ) and $$^7_{\varXi }\mathrm {H}(\frac{1}{2}^+,\frac{3}{2})$$ Ξ 7 H ( 1 2 + , 3 2 ) hypernuclei are also clearly bound with respect to the thresholds $$^4\mathrm {He} + \varXi $$ 4 He + Ξ and $$^6\mathrm {He} +\varXi $$ 6 He + Ξ , respectively. The binding of all these $$\varXi $$ Ξ systems is predominantly due to the attraction of the chiral $$\varXi $$ Ξ N potential in the $$^{33}S_1$$ 33 S 1 channel. A perturbative estimation suggests that the decay widths of all the observed states could be rather small.