Possible Existence of Neutron-Proton Halo in 6Li


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”.

[1] Riisager K 2013 Phys Scr T 152 014001; Tanihata I 2013 Progr Part and Nucl Phys 68 215

[2] Robicheaux F 1999 Phys Rev A 60 p1706

[3] Jensen A S, Riisager K, Fedorov D V and Garrido E 2004 Rev Mod Phys 76 (1) 215-261

[4] Izosimov I N 2017 Phys At Nucl 80 867–876

[5] Arai K, Suzuki Y and Varga K 1995 Phys Rev C 51 2488; Arai K et al 1996 Phys Rev C54 132

[6] Danilov A N, Belyaeva T L, Demyanova A S, Goncharov S A and Ogloblin A A 2009 Phys Rev C 80 054603

[7] Givens R W, Brussel M K, Yavin A I 1972 Nucl Phys A 187 490

[8] Sakuta S B, Burtebayev N, Burtebayeva J T et al 2014 ACTA PHYSICA POLONICA B 45 1853

[9] Burtebayev N, Burtebayeva J T, Glushchenko N V et al 2013 Nucl Phys A 909 20

[10] Goncharov S A and Izadpanah A 2007 Phys At Nucl 70 18; Goncharov S A and Izadpanah A 2007 Phys At Nucl 70 1491

[11] P.D.Kunz 1974 the code DWUCK4 University of Colorado report extended version of J. R. Comfort (unpublished)

[12] Danilin B V, Zhukov M V, Korsheninnikov A A, Chulkov L V and Efros V D 1989 Phys At Nucl 49 351

[13] Demyanova A S et al 2017 Phys At Nucl 80 (5) 831