Behavior of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow/><mml:mrow><mml:mn>7</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi mathvariant="normal">Be</mml:mi><mml:mo>(</mml:mo><mml:mi>p</mml:mi><mml:mo>,</mml:mo><mml:mi>γ</mml:mi><mml:mrow><mml:msup><mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mn>8</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi mathvariant="normal">B</mml:mi></mml:math>astrophysical<b><i>S</i></b>factor near zero energy

The astrophysical S factor of the ${}^{7}\mathrm{Be}(p,\ensuremath{\gamma}{)}^{8}\mathrm{B}$ radiative capture reaction is analyzed at zero energy in a simplified potential model where the scattering wave function and its energy derivative at zero energy are replaced by their asymptotic expressions. A positive (negative) scattering length in the initial s wave reduces (increases) the value of $S(0).$ The ratio ${S}^{\ensuremath{'}}(0)/S(0)$ is much more sensitive to the scattering length than $S(0).$ The effective range of the initial wave is found to play a negligible role. Existing models suggest a negative value for the scattering length, but not large enough to lead to important corrections.

Hali tarjima qilinmagan