Density distribution of ${}^8\mathrm{Li}$ and ${}^8\mathrm{B}$ and capture reaction at low energy

Reaction cross sections of ${}^8\mathrm{Li}$ on stable targets were measured at intermediate energies. With the existing experimental data of interaction cross sections at 790 MeV/nucleon the nucleon density distribution of ${}^8\mathrm{Li}$ was extracted by the use of the modified Glauber model. Meanwhile, the existing data of ${}^8\mathrm{B}$ have been also reanalyzed. Structures of ${}^8\mathrm{Li}$ and ${}^8\mathrm{B}$ were compared through the density. On the basis of dilute surface densities, the discussion of ${}^7\mathrm{Li}\left(n,\gamma \right){}^8\mathrm{Li}$ and ${}^7\mathrm{Be}\left(p,\gamma \right){}^8\mathrm{B}$ capture reactions was performed within the framework of the direct capture reaction mechanism. The calculations agreed quite well with the experimental data as well as other analyses.

Figure 1

The energy dependent ${\sigma }_R$ of ${}^8\mathrm{B}$ and ${}^8\mathrm{Li}$. The data of ${}^8\mathrm{B}$ are taken from Refs. [14, 17, 20]. The present data of ${}^8\mathrm{Li}$ are represented by closed symbols; the open symbols are taken from Ref. [13].

Figure 2

The density distributions of ${}^8\mathrm{B}$ and ${}^8\mathrm{Li}$. The shaded areas are errors.

Figure 3

The fit of ${}^8\mathrm{B}$ with the multicluster model density distribution. Obviously, the difference between two kinds of density is in the inner part.

Figure 4

Radial integrands for direct radiative neutron capture from the continuum state ${\psi }_c$ to the ground state ${\psi }_b$ of ${}^7\mathrm{Li}+n$ at neutron energy $E_n=500\mathrm{keV}$.

Figure 5

Capture cross sections for ${}^7\mathrm{Li}\left(n,\gamma \right){}^8\mathrm{Li}$. The dashed line is a $1/v$ fit by Blackmon et al. [4].

Figure 6

$S$ factor for ${}^7\mathrm{Be}\left(p,\gamma \right){}^8\mathrm{B}$, the calculation does not take into account the resonance. The dashed line is the result of the cluster model [30]. The experimental data are from Refs. [31, 32, 33, 34, 35].