Possible Existence of Neutron-Proton Halo in 6Li

Abstract

One of the most recent results was the determination of the proton halo in the first excited state of the 13N nucleus using of an analog of the MDM method for the charge exchange reactions (3He, t). It turned out that this state has the same radius as the mirror state 1/2+, 3.09 MeV in 13C.This observation allows us to take the next step and try to apply this approach to measure the radii of states. The increased radii in the isobar - analogue states of the 6He-6Li-6Be triplet, which may also have a halo structure, are not excluded. As a first step, we analyzed the published differential cross sections for inelastic scattering of 3He + 6Li with the excitation of the 2.19 MeV, 3+ state at energies 34 and 72 MeV and 3.56 MeV, 0+ state at energies 24.6 and 27 MeV. Probably the state 0+, 3.56 MeV has the same radius as its ”Borromian” isobar analogue 6He and is neutron-proton halo. The predicted enlarged radius because of the more extended wave function p - n, apparently, does not take place. We recall that the spatial structure of the 6He nucleus was predicted to be quite complex, in which correlations of two types appeared: ”cigar” and ”dineutron”. The question arises: does the structure of the state change so much when passing from 6He to the isobar-analoguein6Li,whichrequirestheintroductionofaspecialkindof“tango-halo”.