Related papers: On the 14C(alpha,gamma) reaction rate
A new thermonuclear $^{17}$O($n$,$\gamma$)$^{18}$O rate is derived based on a complete calculation of the direct-capture (DC) and resonant-capture contributions, for a temperature region up to 2 GK of astrophysical interest. We have firstly…
One of the main neutron sources for the astrophysical s-process is the reaction 13C({\alpha},n)16O, taking place in thermally pulsing Asymptotic Giant Branch stars at temperatures around 90 MK. To model the nucleosynthesis during this…
We estimate the impact on the stellar evolution of the uncertainties in the $3\alpha$ and the $^{12}{\rm C}(\alpha,\gamma)^{16}{\rm O}$ reaction rates [...]. We calculated models of low- and intermediate-mass stars for different values of…
The 40Ca(alpha,gamma)44Ti reaction is believed to be the main production channel for the radioactive nuclide 44Ti in core-collapse supernovae. Radiation from decaying 44Ti has been observed so far for two supernova remnants, and a precise…
The radiative capture cross sections of $^{12}$C($\alpha$,$\gamma$)$^{16}$O and derived reaction rates are calculated from the direct capture potential model. The resulting $S$-factor at low energies is found to be dominated by $E$2…
Asymptotic normalization coefficients (ANCs) for 8Li->7Li+n have been extracted from the neutron transfer reaction 13C(7Li,8Li)12C at 63 MeV. These are related to the ANCs in 8B->7Be+p using charge symmetry. We extract ANCs for 8B that are…
Background: The ($\alpha$,n) and ($\alpha$,$\gamma$) reactions on $^{17,18}$O have significant impact on the neutron balance in the astrophysical $s$-process. In this scenario stellar reaction rates are required for relatively low…
Within the framework of the modified potential cluster model with forbidden states, the $^{13}$N($p,\gamma $)$^{14}$O reaction rate and the astrophysical $S$-factor are considered. It is shown that the first $p^{13}$% N resonance determines…
For many years, astronomers have promised that the study of pulsating white dwarfs would ultimately lead to useful information about the physics of matter under extreme conditions of temperature and pressure. We can now make good on that…
The efficiency of the slow neutron-capture process in massive stars is strongly influenced by neutron-capture reactions on light elements. At low metallicity, $^{16}$O is an important neutron absorber, but the effectiveness of $^{16}$O as a…
Recently, the triple-\alpha (3\alpha) process, by which three 4He nuclei are fused into a 12C nucleus in stars, was studied by different methods in solving the quantum mechanical three-body problem. Their results of the thermonuclear…
We evaluate two dominant nuclear reaction rates and their uncertainties that affect 44Ti production in explosive nucleosynthesis. Experimentally we develop thick-target yields for the 40Ca(alpha,gamma)44Ti reaction at E(alpha) = 4.13, 4.54,…
It has been suggested that hydrogen ingestion into the helium shell of massive stars could lead to high $^{13}$C and $^{15}$N excesses when the shock of a core-collapse supernova passes through its helium shell. This prediction questions…
The astrophysical reaction rates of the 16O(a,g)20Ne capture reaction and its inverse 20Ne(g,a)16O photodisintegration reaction are given by the sum of several narrow resonances and a small direct capture contribution at low temperatures.…
Within the framework of the modified potential cluster model with a classification of orbital states according to Young diagrams, the possibility of describing experimental data for total cross sections of the neutron radiative capture on…
We investigate effects of triple-$\alpha$ and $^{12}\rm C(\alpha,\gamma) ^{16}O$ reaction rates on the production of supernova yields for a massive star of 25 $M_{\odot}$. We combine the reaction rates to examine the rate dependence, where…
The s-process in AGB stars produces elements with atomic mass numbers $A\gtrsim60$ through successive neutron captures and beta decays. In stellar environments where the s-process occurs, neutrons quickly thermalize, adopting a…
The $^{18}{\rm O}(p,\alpha)^{15}{\rm N}$ reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside AGB stars as well as oxygen and nitrogen isotopic ratios in meteorite grains. Thus the…
Gamma-ray angular distributions for the resonances at Ep = 550 keV and 1747 keV of the radiative capture reaction 13-C(p,g)14-N have been measured, using intense proton beams on isotopically pure 13-C targets. Relative intensities for the…
The absolute cross section of the $^{13}$C($\alpha$,n)$^{16}$O reaction has been measured at E$_{\alpha}$ = 0.8 to 8.0 MeV with an overall accuracy of 4%. The precision is needed to subtract reliably a background in the observation of…