Related papers: Direct capture astrophysical S factors at low ener…
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…
Three related features of the astrophysical S-factor, (S_{17}), for low energies are an upturn as the energy of the proton goes to zero, a pole at the proton separation energy and a long ranged radial integral peaking at approximately 40…
The astrophysical $^7{\rm Be}(p, \gamma)^8{\rm B}$ direct capture process is studied in the framework of a two-body single-channel model with potentials of the Gaussian form. A modified potential is constructed to reproduce the new…
The low-energy behavior of the astrophysical S-factor for E1 direct radiative captures a(p,gamma)b leading to loosely bound final states (b=a+p) is investigated. We derive a first-order integral representation for S(E) and focus on the…
The CNO cycle is the main source of energy in stars more massive than our Sun. It defines the energy production and the duration contributes in determining the lifetime of massive stars. The cycle is an important tool for the determination…
The astrophysical S-factor of the 4He-12C radiative capture is calculated in the potential model at the energy range 0.1-2.0 MeV. Radiative capture 12C(\alpha,\gamma)16O is extremely relevant for the fate of massive stars and determines if…
The radiative capture of protons by $^7$Be, which is the source of $^8$B that $\beta$-decays emitting the majority of solar neutrinos measured on earth, has not yet been measured at astrophysically relevant energies. The recommended value…
The astrophysical $S$-factor for the reaction $^7$Be(p,$\gamma$)$^8$B up to an energy of 2~MeV (c.m.) and the capture cross section of $^7$Li(n,$\gamma$)$^8$Li up to 1~MeV (c.m.) are calculated using the Direct Capture model (DC). Both…
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…
A theoretical study of the 7Be(p,gamma)8B reaction in the astrophysical energy range with the use of ab initio methods is presented. The used approaches are No-Core Shell Model and Cluster Channels Orthogonal Functions Method. The scheme…
The cross section of the 16O(a,g)20Ne capture reaction is analyzed at low energies where the direct capture mechanism is dominant. For temperatures below T9 = 0.2 the resulting astrophysical reaction rate is about a factor of two higher…
Final results from an exclusive measurement of the Coulomb breakup of 8B into 7Be+p at 254 A MeV are reported. Energy-differential Coulomb-breakup cross sections are analyzed using a potential model of 8B and first-order perturbation…
Astrophysical S-factors at zero energy for the direct nuclear capture reactions $^{3}{\rm He}(\alpha, \gamma)^{7}{\rm Be}$, $^{3}{\rm H}(\alpha, \gamma)^{7}{\rm Li}$ and $^{7}{\rm Be}(p, \gamma)^{8}{\rm B}$ are estimated within the…
The 15N(p,g)16O reaction represents a break out reaction linking the first and second cycle of the CNO cycles redistributing the carbon and nitrogen abundances into the oxygen range. The reaction is dominated by two broad resonances at Ep =…
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 $^{13}$C($\alpha$,$n$)$^{16}$O reaction at low energies is studied by constructing an effective field theory. We choose a separation scale at $E=1$~MeV, where $E$ is the initial $\alpha$-$^{13}$C energy in center-of-mass frame, just…
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 $^{14}\textrm{N(p,}\gamma\textrm{)}^{15}\textrm{O}$ reaction is the slowest reaction of the carbon-nitrogen cycle of hydrogen burning and thus determines its rate. The precise knowledge of its rate is required to correctly model…
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 astrophysical $S$ factor for the radiative proton capture process on the $^{15}\mathrm{N}$ nucleus, i.e., $^{15}\mathrm{N}(p, \gamma)^{16}\mathrm{O}$, at stellar energies are studied within the framework of the cluster effective field…