Speakers
Description
The chemical abundance of different elements in Universe depends substantially on the nuclear structure and nuclear reactions. In order to determine the premordial $^7Li$ abundance in the early Universe, the $^3H(\alpha,\gamma)^7Li$ radiative-capture process is of great astronomical relevance. The calculations of primordial nucleosynthesis offer some thorough and comprehensive assessments of main assumptions of the big-bang model. The key information required for these calculations is nuclear reaction rate $N_A <\sigma v>$, which further depends on the velocity-averaged cross section ($\sigma$) of the nuclear raection. Astrophysical S-factor calculations also require the total cross section of any reaction. The cross section for $^3He(\alpha,\gamma)^7Be$ Astrophysical reaction has already been obtained by our group for laboratory energies up-to $9$ $MeV$. In this work, we have calculated cross section for the reaction $^3H(\alpha,\gamma)^7Li$ by calculating scattering phase shifts using Phase function method. The phase shifts are calculated for laboratory energies below $15$ MeV for $\frac{5}{2}^-$ and $\frac{7}{2}^-$ resonant states of $^7Li$ (partial wave $\ell=3$). The calculated resonance energies ($E_r$) and width of resonance $\Gamma$ are: $E_r=2.19$ $MeV$ ($exp = 2.18$ $MeV$), $\Gamma= 0.090$ $MeV$ ($exp = 0.069$ $MeV$) for $\frac{7}{2}^-$ resonant state and $E_r= 3.60$ $MeV$ ($exp=4.14$ $MeV$), $\Gamma= 0.704$ $MeV$ ($exp=0.918$ $MeV$) for $\frac{5}{2}^-$ resonant state.
| Session | Astroparticle Physics and Cosmology |
|---|
