Related papers: Is it possible to determine the S-factor of the he…
The problem of the magnitude of the S--factor of the hep process $p + {^3\mathrm{He}} \to {^4\mathrm{He}} + e^+ + \nu_e$ is one of the most important unsolved problems in nuclear astrophysics. The magnitude of $S(hep)$ has also an important…
High energy solar neutrinos can come from the hep reaction ^3He(p,\nue^+)^4He with a large end point energy of 18.8 MeV. Understanding the hep reaction may be important for interpreting solar neutrino spectra. We calculate the contribution…
The results of a new calculation of the astrophysical S-factor for the proton weak capture on 3He are here reviewed. The methods used to obtain very accurate initial and final state wave functions and to construct the nuclear weak current…
We present a new accurate analysis of the $^3$He$(p,e^+\nu_e)$${}^4$He (''hep'') reaction at astrophysical energies. The S-factor is computed using a state-of-the-art method to calculate the four-nucleon scattering and bound-state wave…
If the low energy cross section for 3He + p goes to 4He + e + nu_e, the `hep' reaction, is > 20 times larger than the best (but uncertain) theoretical estimates, then this reaction could significantly influence the electron energy spectrum…
The $Hep$ process is a weak-interaction reaction, $He3 + p \to He4 + e^+ + \nu_e$, which occurs in the sun. There is renewed interest in $Hep$ owing to current experimental efforts to extract from the observed solar neutrino spectrum…
The astrophysical factor for the proton weak capture on 3He is calculated with correlated-hyperspherical-harmonics bound and continuum wave functions corresponding to a realistic Hamiltonian consisting of the Argonne v18 two-nucleon and…
The Sudbury Neutrino Observatory has recently finished its third and final phase, and has accumulated over 1082 days of neutrino data, spanning the energy range from approximately 5-20 MeV. Almost all the observed neutrinos are due to the…
The $^3$He$(\alpha,\gamma)^7$Be radiative capture reaction plays a key role in the creation of elements in stars as well as in the production of solar neutrinos, the observation of which is one of the main tools to study the properties of…
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…
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…
Measurements of the elastic scattering cross section of 3He and 4He are important in order to improve constraints on theoretical models of 4He(3He,g)7Be, a key reaction in Big Bang nucleosynthesis and solar neutrino production. The…
Among the solar fusion reactions, the rate of the $^7$Be($p,\gamma$)$^8$B reaction is one of the most difficult to determine rates. In a number of previous experiments, its astrophysical $S$-factor has been measured at $E$ = 0.1-2.5 MeV…
The LIT approach is tested for the calculation of astrophysical S-factors. As an example the S-factor of the reaction 2H(p,gamma)3He is considered. It is discussed that a sufficiently high density of LIT states at low energies is necessary…
The astrophysical S-factor for the proton weak capture on 3He is calculated with correlated-hyperspherical-harmonics bound and continuum wave functions corresponding to realistic Hamiltonians consisting of the Argonne v14 or Argonne v18…
We investigate the energy dependence of the astrophysical $S$ factor for the reaction $^7$Be$(p,\gamma)^8$B, the primary source of high-energy solar neutrinos in the solar $pp$ chain. Using simple models we explore the model dependence in…
The 3He(4He,gamma)7Be reaction plays an important role in determining the high energy solar neutrino flux and in understanding the abundances of primordial 7Li. The present paper reports a new precision measurement of the cross sections of…
In nuclear astrophysics, the experimental scenario is still unclear for BBN relevant energies from 30-300 keV. Here, we report our measurements of cross section and astrophysical S(E) factor for pd capture reaction using proton beam…
The plasma astrophysical S factor for the 3He(D, p)4He fusion reaction was measured for the first time at temperatures of few keV, using the interaction of intense ultrafast laser pulses with molecular deuterium clusters mixed with 3He…
Using effective field theory, we calculate the S-factor for the hep process in a totally parameter-free formulation. The transition operators are organized according to chiral counting, and their matrix elements are evaluated using the…