Measurement of the internal pair emission branch of the 7.654-MeV state of C 12 , and the rate of the stellar triple- α</mml…
1977; American Institute of Physics; Volume: 15; Issue: 3 Linguagem: Inglês
10.1103/physrevc.15.1072
ISSN1538-4497
AutoresR. G. H. Robertson, R. A. Warner, Sam M. Austin,
Tópico(s)Astro and Planetary Science
ResumoThe internal pair decay of the ${\mathrm{O}}^{+}$ 7.65-MeV state of $^{12}\mathrm{C}$ has been observed in coincidence with inelastic protons from $^{12}\mathrm{C}(p, {p}^{\ensuremath{'}})^{12}\mathrm{C}(7.65)$, using a plastic scintillator of essentially $4\ensuremath{\pi}$ sr solid angle. The branching ratio measured, $\frac{{\ensuremath{\Gamma}}_{\ensuremath{\pi}}}{\ensuremath{\Gamma}}=(6.0\ifmmode\pm\else\textpm\fi{}1.1)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$, is in excellent agreement with the previous measurement by Alburger, and reduces the uncertainty in the stellar triple-$\ensuremath{\alpha}$ reaction rate by almost a factor of 2. Implications for the astrophysical production of $^{12}\mathrm{C}$ and $^{16}\mathrm{O}$ are discussed.NUCLEAR STRUCTURE $^{12}\mathrm{C}$, 7.654-MeV state; measured $\frac{{\ensuremath{\Gamma}}_{\ensuremath{\pi}}}{\ensuremath{\Gamma}}$. Stellar helium burning.
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