相关论文: Nature of the first excited state of He-4
Two new low-lying $^6$He levels at excitation energies of about 2.4 and 2.9 MeV were observed in the experimental investigation of the p-$\alpha$ coincidence spectra obtained by the $^3$H($^4$He,p$\alpha$)2n four-body reaction at $E_{\rm…
We investigate the properties of the excited state of $^4\mathrm{He}$, $^4\mathrm{He}^*$, within the framework of Efimov physics and its connection to the unitary point of the nuclear interaction. We explore two different approaches to…
The d+N systems are studied in a three-body model, using phenomenological N-N interactions. The scattering matrices are calculated by using the Kohn-Hulthen variational method. Then, they are analytically continued to complex energies and…
A benchmark study is performed for the excited state of $^4$He. When the Coulomb interaction is switched off, the $^4$He nucleus exhibits a bound excited state in the vicinity of $p-{}^3$H threshold. As the Coulomb interaction is gradually…
We study the low-energy 3/2- and 1/2- states of He-5 and Li-5 in a microscopic cluster model. The scattering phase shifts of Bond (alpha+n) and of Schwandt (alpha+p), respectively, are reproduced well. We determine the resonance parameters…
The elastic resonance scattering protons decayed from $^{11}$B to the ground state of $^{10}$Be were measured using the thick-target technique in inverse kinematics at the Heavy Ion Research Facility in Lanzhou (HIRFL). The obtained…
Properties of the first excited state of the nucleus 9Be are discussed based on recent (e,e') and (gamma,n) experiments. The parameters of an R-matrix analysis of different data sets are consistent with a resonance rather than a virtual…
The isoscalar monopole excitation of 4He is studied within a few-body ab initio approach. We consider the transition density to the low-lying and narrow 0+ resonance, as well as various sum rules and the strength energy distribution itself…
We calculate $^3$He+$p$ scattering phase shifts in two different microscopic cluster models, Model T and Model C, in order to show the effects of tensor force as well as $D$-wave components in the cluster wave function. Model T employs a…
Measurements of the t-t and p-t coincidence events in the $^3$H ($\alpha$, ttp) reaction have been obtained at $E_\alpha$ incident energy of 67.2 MeV. Various appropriate angular configurations of detectors were chosen in order to observe…
Excited states of $^4$He are studied in four-body calculations with explicitly correlated Gaussian bases. All the levels below $E_{\rm x}$=26 MeV are reproduced reasonably well using realistic potentials. An analysis is made to show how the…
The photodetachment cross section of He^- has been measured in the photon energy range 2.9 eV to 3.3 eV in order to investigate doubly excited states. Measurements were made channel specific by selectively detecting the residual He atoms…
The He3(He3,2p)He4 and H3(H3,2n)He4 reactions are studied in a microscopic cluster model. We search for resonances in the He3+He3 and He4+p+p channels using methods that treat the two- and three-body resonance asymptotics correctly. Our…
Electric dipole ($E1$) response of $^{6}$He is studied with a fully microscopic six-body calculation. The wave functions for the ground and excited states are expressed as a superposition of explicitly correlated Gaussians (CG). Final state…
It is found here that the 1/2+ first excited state of 9Be is a virtual state with the energy of -23.5 KeV. The line shape for the excitation of the state is approximated with a simple analytic form based on the effective range expansion.…
The recent precise experimental determination of the monopole transition form factor from the ground state of $^4$He to its $0^+_2$ resonance via electron scattering has reinvigorated discussions about the nature of this first excited state…
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…
The four-boson universality suggests the existence of the second excited tetramer state in a system of cold ${}^4\mathrm{He}$ atoms. It is not bound but could be seen as a resonance in the atom-trimer scattering. This process is rigorously…
The existence of the $0_3^+$ and $0_4^+$ states around 10 MeV excitation energy in ${^{12}{\rm C}}$ is confirmed by a fully microscopic 3$\alpha$ cluster model. Firstly, a GCM (generator coordinate method) calculation is performed by…
Absolute cross sections for charge exchange, ionization, stripping and excitation in K^(+) - He collisions were measured in the ion energy range 0.7 - 10 keV. The experimental data and the schematic correlation diagrams are used to analyze…