THE REACTION ⁸Li(n,γ)⁹Li AT ASTROPHYSICAL ENERGIES AND ITS ROLE IN PRIMORDIAL NUCLEOSYNTHESIS

Abstract

The possibility of describing available experimental data for the total cross sections of neutron radiative capture on 8Li at thermal and astrophysical energies was considered within the framework of the modified potential cluster model with the state classification of nuclear particles according to the Young tableaux. Our approach allows one to transmit available data in the energy range 0.1–1.0 MeV quite well, and predicts the behavior of the total cross sections at super-low energies, down to 25.3 × 10−9 MeV.

Study of the nucleon radiative captures 8Li(n,γ)9Li, 9Be(p,γ)10B, 10Be(n,γ)11Be, 10B(p,γ)11C, and 16O(p,γ)17F at thermal and astrophysical energies

“…Our calculations 94 of the E1 cross section for the GS potential from row 2 of Table 2 and the scattering potential from row 2 of Table 3 Table 3 the thermal cross section has the value of 41.2 mb and for the scattering potential of the zero depth without FS, a value of 41.4 mb was obtained. In Ref.…”

“…The parameters of these potentials V L and  L , and also basic characteristics of the nucleus obtained with them (the binding energy E bnd , the asymptotic constant C W , the mass radius <R> m and the charge radius <R> ch ) are listed in Table 2 of paper. 94 All these potentials lead to the binding energy of -4.063900 MeV with an accuracy of the finite-difference method (FDM) used here for searching energy equal to 10 -6 MeV. The determination of the calculated expressions for the radii is given, for example, in Refs.…”

“…Because our calculations 94 do not confirm the large value of the 8 Li(n,) 9 Li reaction rate (see Table 4), we can draw a conclusion that the essential part of 8 Li will be used for alpha capture with the formation of 11 B. Therefore, the 8 Li(n,) 9 Li reaction does not prevent the formation of nuclei with A > 12 with the help of the reaction sequence 8 Li(,n) 11 B(n,) 12 Be( − ) 12 C(n,)… This means that in the inhomogeneous early Universe, nucleosynthesis in the regions rich in neutrons could produce isotopes with A > 12, whereas nucleosynthesis at the standard big bang finishing at the production of 7 Li.…”

Radiative p 16O Capture at Astrophyiscal Energies

“…Furthermore, in [15,16] in the MPCM with tensor forces the possibility of the correct reproduction practically of all characteristics of 6 Li was demonstrated, including its quadrupole moment. Subsequently, in [17][18][19][20] on the basis of the MPCM we have presented the possibility of description of the astrophysical S-factors or the total cross sections of almost 30 He, 4 He 12 C systems at thermal and astrophysical energies (see also [3][4][5][6][7][8]). …”

“…Previously, in [1] on the basis of the modified potential cluster model (MPCM) [2][3][4][5][6][7][8] the possibility of description the coulomb form-factors of lithium nuclei was shown. This model uses intercluster potentials obtained on the basis of the elastic scattering phase shifts [9], taking into account the presence of the forbidden states (FSs) in wave functions (WFs) of system [10,11].…”