Astrophysical factor for the radiative capture reaction α+<i>d</i><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mo>→</mml:mo></mml:mrow><mml:mrow><mml:mn>6</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>Li+γ
Abstract
We consider the radiative capture process \ensuremath{\alpha}+d${\ensuremath{\rightarrow}}^{6}$Li+\ensuremath{\gamma} at energies, ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.}$\ensuremath{\le}300 keV, that are relevant for astrophysical processes. Due to the peripheral character of the reaction, the overall normalization of the astrophysical factor ${\mathit{S}}_{24}$ is entirely governed by one quantity, the asymptotic normalization coefficient ${\mathit{C}}_{01}$ for $^{6}\mathrm{\ensuremath{\alpha}}$+d. Using the recently well established value for this constant ${\mathit{C}}_{01}$=2.3\ifmmode\pm\else\textpm\fi{}0.12 ${\mathrm{fm}}^{\mathrm{\ensuremath{-}}1/2}$, we calculated ${\mathit{S}}_{24}$ taking into account both E1 and E2 contributions. Our recommended value for ${\mathit{S}}_{24}$ is 2.57 MeV nb at the most effective energy for the capture reaction in astrophysical processes, ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.}$=70 keV, which gives a reaction rate 0.036 ${\mathrm{cm}}^{3}$ ${\mathrm{mole}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ at the temperature 0.8\ifmmode\times\else\texttimes\fi{}${10}^{9}$ K. We found a significant energy dependence of ${\mathit{S}}_{24}$ at astrophysical energies. At energies of less than 110 keV, the E1 component dominates over the E2 component. At ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.}$=70 keV, the E1 contribution to the total transition is about 58%.