Darmstadt 2008 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HK: Fachverband Physik der Hadronen und Kerne

HK 36: Kern- und Teilchen-Astrophysik

HK 36.5: Vortrag

Donnerstag, 13. März 2008, 18:00–18:15, 2B

Precision study of the ¹⁴N(p,γ)¹⁵O reaction at LUNA — •Michele Marta¹, Daniel Bemmerer¹, Ralf Kunz², Claus Rolfs², Frank Strieder², and Hanns-Peter Trautvetter² for the LUNA collaboration — ¹Forschungszentrum Dresden-Rossendorf, 01328 Dresden, Germany — ²Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany

The rate of the hydrogen-burning CNO cycle is controlled by the slowest reaction, ¹⁴N(p,γ)¹⁵O. 15-30% of the total cross section are contributed by radiative capture to the ground state in ¹⁵O. Previous extrapolated S-factors for this ground state contribution disagree by a factor 2. The precision of those previous studies had been limited by a sizable true coincidence summing correction. In a new experiment using a segmented Clover detector deep underground at LUNA, the summing correction has been reduced by a factor 30, so existing R-matrix fits can now be precisely tested. The present data enable a direct measurement of the metallicity at the center of the Sun by detecting solar CNO neutrinos, for example at Borexino.