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arXiv · 0804.1934

Lifetime measurement of the 6792 keV state in 15O, important for the astrophysical S factor extrapolation in 14N(p,g)15O

D. Schuermann·R. Kunz·I. Lingner·C. Rolfs·F. Schuemann·F. Strieder·H. -P. Trautvetter
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Abstract

We report on a new lifetime measurement of the E_x=6792 keV state in 15O via the Doppler-shift attenuation method at the E=259 keV resonance in the reaction 14N(p,g)15O. This subthreshold state is of particular importance for the determination of the ground state astrophysical S factor of 14N(p,g)15O at stellar energies. The measurement technique has been significantly improved compared with previous work. The conclusion of a finite lifetime drawn there cannot be confirmed with the present data. In addition, the lifetime of the two states at E_x=5181 and 6172 keV have been measured with the same technique in order to verify the experimental method. We observe an attenuation factor F(tau)>0.98 for the E_x =6172 and 6792 keV states, respectively, corresponding to tau<0.77 fs. The attenuation factor for the E_x=5181 keV state results in F(tau)=0.78+/-0.02 corresponding to tau=8.4+/-1.0 fs in excellent agreement with literature.

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D. Schuermann, R. Kunz, I. Lingner, C. Rolfs, F. Schuemann, F. Strieder, H. -P. Trautvetter. 2008-04-11. Lifetime measurement of the 6792 keV state in 15O, important for the astrophysical S factor extrapolation in 14N(p,g)15O. https://doi.org/10.1103/physrevc.77.055803

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