Sub-Coulomb<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">α</mml:mi></mml:math>Transfers on<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>C</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>12</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>and the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>C</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>12</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow><mml:mo>(</mml:mo><mml:mi mathvariant="italic">α</mml:mi><mml:mo>,</mml:mo><mml:mi mathvariant="italic">γ</mml:mi><mml:mo>)</mml:mo><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>O</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>16</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">S</mml:mi></mml:math>Factor

The ${}^{12}\mathrm{C}(\ensuremath{\alpha},\ensuremath{\gamma}{)}^{16}\mathrm{O}$ reaction is crucial for the understanding of He burning in massive stars, but the low-energy cross section is highly uncertain. To address this problem we have measured at sub-Coulomb energies total cross sections for the ${}^{12}\mathrm{C}{(}^{6}\mathrm{Li},d{)}^{16}\mathrm{O}$ and ${}^{12}\mathrm{C}{(}^{7}\mathrm{Li},t{)}^{16}\mathrm{O}$ reactions to the bound ${2}^{+}$ and ${1}^{\ensuremath{-}}$ states of ${}^{16}\mathrm{O}$. The data are analyzed to obtain the reduced $\ensuremath{\alpha}$ widths of these states. Together with capture and phase-shift data, these results provide for a more accurate determination of the low-energy $12\mathrm{C}(\ensuremath{\alpha},\ensuremath{\gamma}{)}^{16}\mathrm{O}$ $S$ factor: ${S}_{E1}(0.3\mathrm{MeV})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}101\ifmmode\pm\else\textpm\fi{}17\mathrm{keV}\mathrm{b}$ and ${S}_{E2}(0.3\mathrm{MeV}){\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}42}_{\ensuremath{-}23}^{+16}\mathrm{keV}\mathrm{b}$ for the $E1$ and $E2$ multipole components of the reaction.

Перевод пока недоступен