1. 34S(p,ϒ)35Cl and 34g,mCl(p,ϒ)35Ar
New calculated reaction rates for the astrophysical mirror rp-reactions
34S(p,ϒ)35Cl and 34g,mCl(p,ϒ)35Ar
Werner Richter
University of Stellenbosch
iThemba LABS, South Africa
Alex Brown, Chris Wrede, Cathleen Fry
National Superconducting Cyclotron
Laboratory, Michigan State University
Richard Longland
North Carolina State University
Pavel Denisenkov, Falk Herwig
University of Victoria
Denis Kurtulgil
Goethe University
Marco Pignateri
University of Hull

2. Preliminary astrophysical impact
Outline
Introduction
Shell-model calculations
The SDPF-MU interaction
Results for the (p,γ) reaction rates
Preliminary astrophysical impact

3. 34S/32S abundance ratio has the potential to
aid in distinguishing pre-solar grains from novae and type II supernovae.
Uncertainties in the 34S(p,γ)35Cl and 34g,mCl(p,γ)35Ar reaction rates translate to uncertainties in 34S production in models of classical novae on oxygen-neon white dwarfs.
J. Jose, Proceedings of Science, NIC XI 050 (2011)

4. Calculation of thermonuclear (p, γ) reaction rates
The properties of many resonances are not well known, thus requiring theoretical input.
These are the calculated partial gamma-decay widths, the proton decay widths (which depend on the spectroscopic factors), and energies.

5. Shell-Model Calculations
Our calculations have been done in a full (0+1)ħω model space using the interaction SDPF-MU and NuShellX. ħ

6. Properties of 34S(p,g)35Cl resonances of both parities

8. Uncertainties estimated using Monte Carlo techniques from Starlib [Longland et al., NPA 841 (2010)].
Total reaction rate shown with low rate and high rate corresponding to the 0.16 and 0.84 quantiles of the cumulative reaction rate distribution.

9. Properties of 34gCl(p,g)35Ar resonances of both parities

12. Properties of 34mCl(p,g)35Ar resonances of both parities

15. Nucleosynthesis simulations
Sulfur isotopic ratios predicted by MESA/NuGrid multi-zone ONe nova model [Denissenkov et al., 2014, MNRAS, 442, 2058].
Thermal communication between 34gCl and 34mCl fully incorporated using EM transition rates between all low-lying 34Cl states.
Premiminary 34S/32S ratio uncertainties from 34g,mCl(p,g)35Ar rates are <13%. Uncertainties from 34S(p,g)35Cl rates are <44%.

16. Conclusions
34S(p,γ)35Cl and 34g,mCl(p,γ)35Ar reaction rates determined by calculating resonance properties using shell model with uncertainties from Monte Carlo method.
Negative parity resonances tend to dominate rates of all reactions considered at nova temperatures. Results can be used to guide experimental studies.
Rates implemented in nova nucleosynthesis code including thermal population of 34mCl isomer. Nucleosynthesis uncertainties associated with shell model calculations not terribly large.

17. THANK YOU !
Thank you !

18. Cross-shell part given by VMU (Otsuka et al. 2010)
THE SDPF-MU interaction
Utsuno et al. (2012) USD for sd shell
GXPF1B for pf shell (Honma et al. 2008)
Monopole interactions VT=0,1 0d3/2,0d5/2 based on SDPF-M (Utsuno et al. 1999)
Monopole and quadrupole pairing matrix elements
<0f7/20f7/2|V|0f7/20f7/2> J=0,2 replaced with those of
KB3 (Poves-Zucker 1981)
Cross-shell part given by VMU (Otsuka et al. 2010)