Rates of the Main Thermonuclear Reactions

Nuclear threshold effects and neutron strength functions

“…The resonance condition, 1 − L n R nn = 0, can be approached in different ways. The logarithmic derivative could have resonant form, e. g., as that proposed by Baz and collaborators [26] in a generalized variant of cusp theory. If the energy dependence of logarithmic derivative L n is considered a parametric one, then the root of resonance equation becomes energy-dependent; it is KapurÄ Peierls approach to resonance [23].…”

Isomeric 0- halo-states in 12Be and 11Li

“…For 9 neutrons different ground state spins, 5/2 + and 1/2 + , are also found for 17 O and 15 C. For the particle unstable nucleus 10 Li different theoretical works predicted the existence of a similar low-lying s-wave intruder state [9,10,11], in such a way that the ground state in 10 Li should correspond to a state with negative parity (the ground state of 9 Li has spin and parity 3/2 − ). The available experimental data concerning the ground state properties of 10 Li are however controversial, although most of them point towards the existence of such a low-lying virtual s-state [12,13,14,15]. This result has also been recently supported in [16].…”

THE p-WAVE THRESHOLD EFFECT AND QUASIRESONANT SCATTERING

“…A Compound Nucleus resonance (π), located in neutron threshold vicinity, |E π − E n | < Γ π , and decaying preferentially in the neutron threshold channel, Γ π ∼ Γ πn , induces a non-negligible threshold effect for s-wave only. Most of the threshold effects observed with light nuclei, (1-p Shell), do belong to this class 4 . The flux transfer to and from the neutron threshold channel is controlled not only by the penetration factors, but also by the spectroscopic neutron reduced width; the reduced width is primary factor governing the flux leakage from the compound nucleus to the channels 27 .…”

“…S-wave threshold effects were observed in some Reactions on Light Nuclei; an extensive review on threshold effects in proton scattering on 1-p Shell nuclei was presented in Ref. 4. As a matter of fact, the corresponding experimental data were not interpreted as evidence for a genuine Threshold Cusp, but rather analyzed in terms of a multiparametric method developed by same authors.…”

“…The Threshold Physics field appears to be more rich in phenomena than in schematic descriptions. Understanding of the physical aspects of the p-wave threshold effect should be of interest not only in Low Energy Nuclear Physics 4 , but also in the other Quantum Scattering fields as Atomic Collisions ( e.g. the dipole induced threshold effects in electron-molecule collisions, see Ref.…”