Speaker
Dr
Rosanna Depalo
(INFN - Sezione di Padova)
Description
The $^{6}$Li(p,$\gamma$)$^{7}$Be reaction is involved in many astrophysical scenario, ranging from Big Bang Nucleosynthesis to pre-main sequence stellar evolution and solar neutrino.
At astrophysical energies, proton capture on $^{6}$Li proceeds through the $^{6}$Li(p,$\alpha$)$^{3}$He and the $^{6}$Li(p,$\gamma$)$^{7}$Be reactions.
The $^{6}$Li(p,$\alpha$)$^{3}$He cross section is well known from the literature, but the measured angular distribution can only be explained introducing positive parity excited states of $^{7}$Be in addition to the known negative parity levels.
Although the existence of positive parity excited states in $^{7}$Be has never been confirmed experimentally, a recent measurement of the $^{6}$Li(p,$\gamma$)$^{7}$Be cross section revealed a resonance-like structure at center of mass energy of 195 keV. The observed S-factor could be reproduced introducing a new $^{7}$Be excited state with E $\approx$ 5800 keV and J$^{\pi}$ = (1/2$^{+}$, 3/2$^{+}$).
The existence of such excited state might also affect the cross section of the $^{3}$He($^{4}$He,$\gamma$)$^{7}$Be reaction and, consequently, the estimated flux of $^{7}$Be solar neutrino.
A new measurement of the $^{6}$Li(p,$\gamma$)$^{7}$Be cross section at proton energies between 50 and 400 keV has been performed at the Laboratory for Underground Nuclear Astrophysics. The poster provides a description of the experimental setup and shows preliminary results of the data analysis.
Primary author
Dr
Rosanna Depalo
(INFN - Sezione di Padova)
