New Cl 34 proton-threshold states and the thermonuclear S 33 ( p , γ ) Cl 34 rate in ONe novae

摘要: Analysis of presolar grains in primitive meteorites has shown isotopic ratios largely characteristic the conditions thought to prevail various astrophysical environments. A possible indicator for a grain ONe nova origin is large $^{33}\mathrm{S}$ abundance: nucleosynthesis calculations predict as much 150 times solar abundance ejecta explosions on massive white dwarfs. This overproduction factor may, however, vary by factors at least 0.01--3 because uncertainties several orders magnitude $^{33}\mathrm{S}$$(p,\ensuremath{\gamma})$$^{34}\mathrm{Cl}$ reaction rate peak temperatures (${T}_{\mathrm{peak}}~0.1\text{\ensuremath{-}}0.4$ GK). These arise due lack nuclear physics information states within $~600$ keV $^{33}\mathrm{S}$$+p$ threshold $^{34}\mathrm{Cl}$ (S${}_{p}$($^{34}\mathrm{Cl}$) = 5143 keV). To better constrain this we have measured, first time, $^{34}\mathrm{S}$($^{3}\mathrm{He}$,$t$)$^{34}\mathrm{Cl}$ over region ${E}_{x}$($^{34}\mathrm{Cl}$) 4.9--6 MeV. We confirm previous and find 15 new energy region. New resonances ${E}_{R}=281(2)$, 301(2), 342(2) may dominate relevant temperatures. Our results could affect predictions sulphur (e.g., $^{32}\mathrm{S}$/$^{33}\mathrm{S}$) that be used diagnostic tools paternity grains.