Related papers: Direct reactions in/for astrophysics
The importance of direct capture for (n,$\gamma$)--reactions on intermediate-- and heavy--mass target nuclei occuring in the s-- and r--process is investigated. It is shown that the direct mechanism is non--negligible for magic and neutron…
Effective energy windows (Gamow windows) of astrophysical reaction rates for (p,gamma), (p,n), (p,alpha), (alpha,gamma), (alpha,n), (alpha,p), (n,gamma), (n,p), and (n,alpha) on targets with 10<=Z<=83 from proton- to neutron-dripline are…
The astrophysical $S$ factor and reaction rates of the direct capture process $^{6}$Li(p,$\gamma)^{7}$Be are estimated within a two-body single-channel potential model approach. Central potentials of the Gaussian-form in the $^2P_{3/2}$ and…
The direct radiative capture process is well described by the spherical potential model. In order for the model to explain direct captures more accurately, the effect of the nuclear deformation has been added and analyzed in this work,…
Nucleosynthesis beyond Fe poses additional challenges not encountered when studying astrophysical processes involving light nuclei. Astrophysical sites and conditions are not well known for some of the processes involved. On the nuclear…
We estimate the ratios of bare astrophysical S-factors at zero incident energy for proton and deuteron induced reactions in a model which assumes a compound nucleus formation probability plus a statistical decay. The obtained ratios agree…
The $^{12}$C+$^{12}$C fusion reaction plays a crucial role in stellar evolution and explosions. Its open reaction channels mainly include $\alpha$, $p$, $n$, and ${}^{8}$Be. Despite more than a half century of efforts, large discrepancies…
Reactions are an important tool to study nuclear structure and for extracting reactions relevant for astrophysics. In this paper we focus on deuteron induced reactions which can provide information on neutron shell evolution as well as…
The sources of nuclear uncertainties in nova nucleosynthesis have been identified using hydrodynamical nova models. Experimental efforts have followed and significantly reduced those uncertainties. This is important for the evaluation of…
In the last years the direct measurement of cosmic rays received a push forward by the possibility of conducting experiments on board long duration balloon flights, satellites and on the International Space Station. The increase in the…
An introduction to nucleosynthesis, the creation of the elements in the big bang, in interstellar matter and in stars is given. The two--step process $^4$He(2n,$\gamma$)$^6$He and the reverse photodisintegration $^6$He($\gamma$,2n)$^4$He…
Massive stars are crucial to galactic chemical evolution for elements heavier than iron. Their contribution at early times in the evolution of the Universe, however, is unclear due to poorly constrained nuclear reaction rates. The competing…
We investigated the impact of uncertainties in neutron-capture and weak reactions (on heavy elements) on the s-process nucleosynthesis in low-mass stars and massive stars using a Monte-Carlo based approach. We performed extensive nuclear…
Direct reaction techniques are powerful tools to study the single-particle nature of nuclei. Performing direct reactions on short-lived nuclei requires radioactive ion beams produced either via fragmentation or the Isotope Separation OnLine…
The methodology for modeling grain-surface chemistry has been greatly improved by taking into account the grain size and fluctuation effects. However, the reaction rate coefficients currently used in all practical models of gas-grain…
The goal of nuclear astrophysics is to measure cross sections of nuclear physics reactions of interest in astrophysics. At stars temperatures, these cross sections are very low due to the suppression of the Coulomb barrier. Cosmic ray…
The well-known astrophysical resonant reaction rate equations for an isolated narrow resonance have been reexamined. The validity of those `look reliable' assumptions used in deriving the analytic reaction rate equations has been checked,…
For the better part of a century the field of nuclear astrophysics has aimed to answer fundamental questions about nature, such as the origin of the elements and the behavior of high-density, low-temperature matter. Sustained and concerted…
Astrochemical surface reactions are thought to be responsible for the formation of complex organic molecules, which are of potential importance for the origin of life. In a situation, when the chemical composition of dust surfaces is not…
The continued interest to the study of the radiative neutron capture on atomic nuclei is caused, on the one hand, by the important role of this process in the analysis of many fundamental properties of nuclei and nuclear reactions, and, on…