Nuclear Theory·nucl-th

Wednesday·April 1, 2020

9 papers—3 primary·6 cross-listed

01
Study of $n +^{3}$ H, $p +^{3}$ He, $p +^{3}$ H, and $n +^{3}$ He scattering with the HH method
M. Viviani🇮🇹 · L. Girlanda🇮🇹 · A. Kievsky🇮🇹 · L.E. Marcucci🇮🇹
The $n +^{3}$ H, $p +^{3}$ He, $p +^{3}$ H, and $n +^{3}$ He elastic and charge exchange reactions at low energies are studied by means of the hyperspherical harmonic method. The considered nuclear Hamiltonians include modern two- and three-nucleon interactions, in particular results are reported in case of chiral two-nucleon potentials, with and without the inclusion of chiral three-nucleon (3N) interactions. A detailed study of the convergence and numerical stability of the method is presented. We have found that the effect the 3N force is in general tiny except for $p +^{3}$ H scattering below the opening of the $n +^{3}$ He channel. In such a case, the effect of 3N forces is appreciable and a clear dependence on the cutoff used to regularize the high-momentum tail of the interactions is observed. Such a dependence is related to the presence of the poorly known sharp $0^{+}$ resonance, considered to be the first excited state of $^{4}$ He.
nucl-th2 citations
02
Properties of $K^{π} = 0_{1}^{+}$ , $K^{π} = 2^{-}$ , and $K^{π} = 0_{1}^{-}$ bands of $^{20}$ Ne probed via proton and alpha inelastic scattering
Yoshiko Kanada-En'yo🇯🇵 · Kazuyuki Ogata🇯🇵
The $K^{π} = 0_{1}^{+}$ , $K^{π} = 2^{-}$ , and $K^{π} = 0_{1}^{-}$ bands of $^{20}$ Ne are investigated with microscopic structure and reaction calculations via proton and $α$ inelastic scattering off $^{20}$ Ne. Structures of $^{20}$ Ne are calculated with variation after parity and total angular momentum projections in the antisymmetrized molecular dynamics(AMD). The $K^{π} = 0_{1}^{+}$ and $K^{π} = 0_{1}^{-}$ bands have $^{16} O + α$ cluster structures, whereas the $K^{π} = 2^{-}$ band shows a $^{12} C + 2 α$ -like structure. Microscopic coupled-channel calculations of proton and $α$ scattering off $^{20}$ Ne are performed by using the proton-nucleus and $α$ -nucleus potentials, which are derived by folding the Melbourne $g$ -matrix $N N$ interaction with AMD densities of $^{20}$ Ne. The calculation reasonably reproduces the observed cross sections of proton scattering at $E_{p} = 25$ --35 MeV and $α$ scattering at $E_{α} = 104$ --386 MeV. Transition properties from the ground to excited states are discussed by reaction analyses of proton and $α$ inelastic processes. Mixing of the $K^{π} = 2^{-}$ and $K^{π} = 0_{1}^{-}$ bands is discussed by detailed analysis of the $0_{1}^{+} \to 3_{1}^{-}$ and $0_{1}^{+} \to 3_{2}^{-}$ transitions. For the $3_{1}^{-}$ state, mixing of the $K^{π} = 0_{1}^{-}$ cluster component in the $K^{π} = 2^{-}$ band plays an important role in the transition properties.
nucl-thPRC(2020)·19 citations
03
Light Neutral Clusters in Supernova Matter
I.V. Panov · A.V. Yudin
The role of weakly bound neutral clusters, such as dineutrons and tetraneutrons, in matter of high density and high temperature is discussed. Under such conditions, which are characteristic of core-collapse supernovae, the lifetime of multineutrons may prove to be sufficiently long for them to have a pronounced effect on the formation of the chemical composition. The influence of the multineutron binding energy and other nuclear properties on the magnitude of the effect being considered is examined.
nucl-thastro-ph.SRPhys.Atom.Nucl.(2019)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Study of n+3H, p+3He, p+3H, and n+3He scattering with the HH method

Properties of Kπ=01+​, Kπ=2−, and Kπ=01−​ bands of 20Ne probed via proton and alpha inelastic scattering

Light Neutral Clusters in Supernova Matter

Affiliations

Study of $n +^{3}$ H, $p +^{3}$ He, $p +^{3}$ H, and $n +^{3}$ He scattering with the HH method

Properties of $K^{π} = 0_{1}^{+}$ , $K^{π} = 2^{-}$ , and $K^{π} = 0_{1}^{-}$ bands of $^{20}$ Ne probed via proton and alpha inelastic scattering