Coulomb breakup of ${}^6\mathrm{Li}$ into $\alpha +\mathrm{d}$ in the field of ion ${}^{208}\mathrm{Pb}$

Abstract

The triple differential cross section of ${}^{208}\mathrm{Pb}{(}^6\mathrm{Li};\alpha ,\mathrm{d}{)}^{208}\mathrm{Pb}$ elastic Coulomb breakup is calculated using the semiclassical method. We fit the parameters of the Woods-Saxon potential using the experimental $\alpha -\mathrm{d}$ phase shifts for different states to describe the relative motion of $\alpha$-particle and deuteron. In order to check the validity of the two particle approach for $\alpha -d$ system we apply a potential model to describe the ${}^2\mathrm{H}(\alpha ,\gamma {)}^6\mathrm{Li}$ radiative capture. Our results for the Coulomb breakup of ${}^6\mathrm{Li}$ show large value of the forward-backward asymmetry of the $\alpha$-particle and deuteron emission around zero energy in the ${}^6\mathrm{Li}$ center-of-mass (c.m.) system. Comparison of the results of our calculation with experimental data gives evidence for the dominance of the Coulomb dissociation mechanism at the $\alpha -d$ relative energy larger than $E_{\alpha d}>300\mathrm{keV}$ and sufficiently big contribution of nuclear distortion at $E_{\alpha d}$ near zero energy, but essentially smaller than the value reported in Ref.[F. Hammache et al. Phys.Rev. C82, 065802 (2010)].

Comments: 11 pages, 5 figures (one figure removed), added the results of new calculations and performed the audit of the text