Excitation of 8Be monopole resonances under αα scattering

Neutron halo in 8He

“…For a long time, this version was used for studying the bound states of two-cluster systems, reactions with a few open channels, interaction of these channels with collective monopole and quadrupole modes, and also processes of full disintegration of light nuclei [20,21,22]. Recently, the AV RGM was actively applied to describe three-cluster systems [23,24,25,26].…”

A microscopic three-cluster model with nuclear polarization applied to the resonances of 7Be and the reaction 6Li(p, 3He)4He

“…We refer to this phenomenon as cluster polarization. One expects cluster polarization to play a role in reactions which involve light nuclei with small separation energy such as the deuteron, 6 Li, 7 Li, and so on. One also expects the effects to be more pronounced at small energies of the colliding nuclei, due to the longer interaction time intervals.…”

“…This system exhibits a well determined set of bound and resonance states, and has been thoroughly studied by many microscopical methods [16][17][18][19][20][21][22][23][24][25]. Moreover, two reactions which are connected to this nucleus, 3 He(α, γ ) 7 Be and 6 Li(p, 3 He) 4 He, are important in astrophysical models [26,27]. The former reaction has been extensively investigated by different microscopic and semi-microscopic methods and is involved in the solar neutrino problem [20,21,23,24,[28][29][30].…”

“…We model the 7 Be nucleus using a many-channel cluster wave function containing both twocluster and three-cluster components. As we wish to consider both the two-cluster components 4 He + 3 He and 6 Li + p, we use the 4 He + d + p three-cluster configuration.…”

“…The first, introduced by Tang et al [1][2][3][4][5][6], considers internal monopole excitations to describe the polarization. The second, introduced by the Kiev-Antwerp collaboration [7][8][9][10][11][12][13][14][15], is based on collective monopole and quadrupole polarizations of the compound nucleus.…”