New ${}^{32}$Cl(p,$\gamma$)${}^{33}$Ar reaction rate for astrophysical rp-process calculations

Abstract

The ${}^{32}$Cl(p,$\gamma$)${}^{33}$Ar reaction rate is of potential importance in the rp-process powering type I X-ray bursts. Recently Clement et al. \cite{CBB04} presented new data on excitation energies for low lying proton unbound states in ${}^{33}$Ar obtained with a new method developed at the National Superconducting Cyclotron Laboratory. We use their data, together with a direct capture model and a USD shell model calculation to derive a new reaction rate for use in astrophysical model calculations. In particular, we take into account capture on the first excited state in ${}^{32}$Cl, and also present a realistic estimate of the remaining uncertainties. We find that the ${}^{32}$Cl(p,$\gamma$)${}^{33}$Ar reaction rate is dominated entirely by capture on the first excited state in ${}^{32}$Cl over the whole temperature range relevant in X-ray bursts. In the temperature range from 0.2 to 1 GK the rate is up to a factor of 70 larger than the previously recommended rate based on shell model calculations only. The uncertainty is now reduced from up to a factor of 1000 to a factor of 3 at 0.3-0.7 GK and a factor of 6 at 1.5 GK.

To be published in Phys. Rev. C

References in corpus (10)

• Astrophysical Reaction Rates From Statistical Model Calculations
• New effective interaction for $pf$-shell nuclei and its implications for the stability of the $N$=$Z$=28 closed core
• Effective interaction for pf-shell nuclei
• Models for Type I X-Ray Bursts with Improved Nuclear Physics
• Nuclear Level Density and the Determination of Thermonuclear Rates for Astrophysics
• Proton Drip-Line Calculations and the Rp-process
• Periodic Thermonuclear X-ray Bursts from GS 1826-24 and the Fuel Composition as a Function of Accretion Rate
• The nuclear reaction waiting points, Mg22, Si26, S30, and Ar34, and bolometrically double peaked type I X-ray bursts
• RADCAP: a potential model tool for direct capture reactions
• Element Synthesis in Stars

Cited by in corpus (12)

• Charged-Particle Thermonuclear Reaction Rates: II. Tables and Graphs of Reaction Rates and Probability Density Functions
• Charged-Particle Thermonuclear Reaction Rates: III. Nuclear Physics Input
• The Path to Improved Reaction Rates for Astrophysics
• Nucleosynthesis in Type I X-ray Bursts
• The importance of nuclear masses in the astrophysical rp-process
• Survey of excited state neutron spectroscopic factors for Z=8-28 nuclei
• Charged-Particle Thermonuclear Reaction Rates: IV. Comparison to Previous Work
• Reaction rates of ${}^{64}$Ge($p,\gamma$)${}^{65}$As and ${}^{65}$As($p,\gamma$)${}^{66}$Se and the extent of nucleosynthesis in type I X-ray bursts
• The Regulated NiCu Cycles with the new ${}^{57}$Cu(p,$\gamma$)${}^{58}$Zn reaction rate and the Influence on Type-I X-Ray Bursts: GS 1826$-$24 Clocked Burster
• New 26P(p,γ)27S thermonuclear reaction rate and its astrophysical implication in rp-process
• New ${}^{63}$Ga(p,$\gamma$)${}^{64}$Ge and ${}^{64}$Ge(p,$\gamma$)${}^{65}$As reaction rates corresponding to the temperature regime of thermonuclear X-ray bursts
• Nuclear Astrophysics in Rare Isotope Facilities