Nuclear reactions in the Sun after SNO and KamLAND

In this brief review we discuss the possibility of studying the solar interior by means of neutrinos, in the light of the enormous progress of neutrino physics in the last few years. The temperature near the solar center can be extracted from Boron neutrino experiments as: $T= (1.57 \pm 0.01) 10^7 K$. The energy production rate in the Sun from pp chain and CNO cycle, as deduced from neutrino measurements, agrees with the observed solar luminosity to about twenty per cent. Progress in extracting astrophysical information from solar neutrinos requires improvement in the measurements of $^3He+$ \\$^4He \to ^7Be+\gamma$ and $p+^{14}N \to ^{15}O+ \gamma$.Comment: To appear in the Proceedings of Beyond the Desert '03, Fourth International Conference on Physics Beyond the Standard Model, Schloss Ringberg, Germany, June 9-14, 200

Destruction of Li-7 and Be-7 in astrophysical environments

The destruction of Li-7 and Be-7 in astrophysical environments is essential for understanding several stellar and cosmological processes and is not well understood, though earlier Li-7 + He-3 experiments have been performed [1]. The primordial abundance of Li-7 after Big Bang Nucleosynthesis (BBN) plays a major role in our understanding of the early universe [2]. The value of the baryon to photon ratio (eta) deduced from BBN combined with measurements of the cosmic microwave background provide some of the strongest and earliest evidence for the existance of non-baryonic dark matter [2]. The destruction of Be-7 during the hot-pp cycle may alter our conclusions on the production of carbon in this process, which is thought to compete with the triple-a process for the production of C-12, as the reaction Be-7(He-3, 2alpha)2p competes with Be-7(He-4, gamma)C-11 and may reduce carbon production [3]. These stellar and cosmological environments involve high temperatures, and thus, effective burning energies (Gamow windows) that are quite high. Experiments using Be-7 targets inevitably involve interactions with Li-7 as background due to the Li-7 daughters from the beta decay of Be-7. The experiments were performed at the Weizmann Institute VDG Laboratory using He-3 beams from 390 keV to 1130 keV on (LiF)-Li-7 foil targets and Be-7 implanted targets. Results from measurements using 10 mug (LiF)-Li-7 foil targets will be discussed