Related papers: Microscopic calculations for solar nuclear reactio…
Cross sections for the 7Be(p,gamma)8B reaction have been measured for E_c.m.= 0.35-1.4 MeV using radioactive 7Be targets. Two independent measurements carried out with different beam conditions, different targets and detectors are in…
The present status of the nuclear reaction rates determining the solar neutrino flux is discussed. This includes the reaction rates for the two branching ratios of the three pp-chains involving the reactions 3He(3He,2p)4He and…
We discuss microscopic cluster model descriptions of two solar nuclear reactions, Be7(p,gamma)B8 and He3(He3,2p)He4. The low-energy reaction cross section of Be7(p,gamma)B8, which determines the high-energy solar neutrino flux, is…
We discuss results and future plans for low-energy reactions that play an important role in current nuclear astrophysics research and that happen to concentrate around the region of A=7. The 7Be(p,gamma)8B and the 3He(4He,gamma)7Be…
We investigate low--energy astrophysical $S$ factors for reactions proceeding through the $^{8}$Be compound system with entrance channels $p+{}^{7}$Li, $n+{}^{7}$Be, and $d+{}^{6}$Li. Using the same microscopic many--channel three--cluster…
The He3(He3,2p)He4 and H3(H3,2n)He4 reactions are studied in a microscopic cluster model. We search for resonances in the He3+He3 and He4+p+p channels using methods that treat the two- and three-body resonance asymptotics correctly. Our…
We present precision measurements of the 3He + 4He --> 7Be reaction in the range ECM = 0.33 to 1.23 MeV using a small gas cell and detection of both prompt gamma rays and 7Be activity. Our prompt and activity measurements are in good…
The nuclear physics input from the 3He(alpha,gamma)7Be cross section is a major uncertainty in the fluxes of 7Be and 8B neutrinos from the Sun predicted by solar models and in the 7Li abundance obtained in big-bang nucleosynthesis…
A microscopic model for three-cluster configurations in light nuclei is presented. It uses an expansion in terms of Faddeev components for which the dynamic eqations are derived. The model is designed to investigate binary channel processes…
The 3He({\alpha},{\gamma})7Be reaction affects not only the production of 7Li in Big Bang nucleosynthesis, but also the fluxes of 7Be and 8B neutrinos from the Sun. This double role is exploited here to constrain the former by the latter. A…
Solar neutrino fluxes depend both on astrophysical and on nuclear physics inputs, namely on the cross sections of the reactions responsible for neutrino production inside the Solar core. While the flux of solar 8B neutrinos has been…
We explore approximations to the effective $S$ factor for the $^7Be(p,\gamma)^8B$ reaction using different approximation for the integral over the Gamov peak. In the temperature range of interest for solar neutrino production, $S_{eff}(E)$…
The radiative capture cross sections for the 3He(alpha,gamma)7Be and 3H(alpha,gamma)7Li reactions are calculated in the fully microscopic fermionic molecular dynamics approach using a realistic effective interaction that reproduces the…
The interpretation of the most recent solar neutrinos experiments requires a good knowledge of the cross section of the reaction 7Be(p,gamma)8B at very small energy (Ecm=18 keV). We have recently measured this cross section for Ecm=0.35-1.4…
The 3He(alpha,gamma)7Be process is a key reaction in both Big-Bang nucleosynthesis and p-p chain of Hydrogen Burning in Stars. A new measurement of the 3He(alpha,gamma)7Be cross section has been performed at the INFN Gran Sasso underground…
We have studied the proton-capture reaction 3H(p,{\gamma})4He. It plays a role in the nucleosynthesis of primordial elements in the early Universe leading to the pre-stellar formation of 4He nuclei. All results of our researches and more…
We study the nonresonant part of the $^7$Be($p,\gamma$)$^8$B reaction using a three-cluster resonating group model that is variationally converged and virtually complete in the $^4$He+$^3$He+$p$ model space. The importance of using adequate…
We consider several nuclear fusion reactions that take place at the center of the sun, which are omitted in the standard pp-chain model. More specifically the reaction rates of the nonradiative production of ^3He, ^7Be, and ^8B nuclei in…
The astrophysical S-factor for the process p7Be --> 8Bgamma of radiative capture by the 8B ground state is described up to 5 MeV, within the modified potential cluster model. The signatures of the S-factor resonances at 0.632, 2.18 and 3.36…
The status of "ab initio" microscopic calculations of the 2H(p,gamma)3He and 3He(p,e+nu_e)4He reactions is reviewed. The methods used to generate accurate nuclear ground- and scattering-state wave functions, and to construct realistic…