Deformation of hypernuclei studied with antisymmetirzed molecular dynamics

An extended version of the antisymmetrized molecular dynamics to study structure of $p$-$sd$ shell hypernuclei is developed. By using an effective $\Lambda N$ interaction, we investigate energy curves of $^9_\Lambda$Be, $^{13}_\Lambda$C and $^{20,21}_\Lambda$Ne as function of nuclear quadrupole deformation. Change of nuclear deformation caused by $\Lambda$ particle is discussed. It is found that the $\Lambda$ in p-wave enhances nuclear deformation, while that in s-wave reduces it. This effect is most prominent in $^{13}_\Lambda$C. The possibility of the parity inversion in $^{20}_\Lambda$Ne is also examined

Modification of triaxial deformation and change of spectrum in $^{25}_{\ \Lambda}MgcausedbyMg caused by \Lambda$ hyperon

The positive-parity states of $^{25}_{\ \Lambda}$Mg with a $\Lambda$ hyperon in $s$ orbit were studied with the antisymmetrized molecular dynamics for hypernuclei. We discuss two bands of $^{25}_{\ \Lambda}$Mg corresponding to the $K^\pi=0^+$ and $2^+$ bands of $^{24}$Mg. It is found that the energy of the $K^\pi = 2^+ \otimes \Lambda_s$ band is shifted up by about 200 keV compared to $^{24}$Mg. This is because the $\Lambda$ hyperon in $s$ orbit reduces the quadrupole deformation of the $K^\pi = 0^+ \otimes \Lambda_s$ band, while it does not change the deformation of the $K^\pi = 2^+ \otimes \Lambda_s$ band significantly.Comment: 19 pages, 3 figure

Superdeformed Λ\Lambda hypernuclei with antisymmetrized molecular dynamics

The response to the addition of a $\Lambda$ hyperon is investigated for the deformed states such as superdeformation in $^{41}_\Lambda$Ca, $^{46}_\Lambda$Sc and $^{48}_\Lambda$Sc. In the present study, we use the antisymmetrized molecular dynamics (AMD) model. It is pointed out that many kinds of deformed bands appear in $^{45}$Sc and $^{47}$Sc. Especially, it is found that there exists superdeformed states in $^{45}$Sc. By the addition of a $\Lambda$ particle to $^{40}$Ca, $^{45}$Sc and $^{47}$Sc, it is predicted, for the first time, that the superdeformed states exist in the hypernuclei $^{41}_\Lambda$Ca and $^{46}_\Lambda$Sc. The manifestation of the dependence of the $\Lambda$-separation energy on nuclear deformation such as spherical, normal deformation and superdeformation is shown in the energy spectra of $^{41}_\Lambda$Ca, $^{46}_\Lambda$Sc and $^{48}_\Lambda$Sc hypernuclei.Comment: 24 pages, 8 figure

FORWARD AND FALSE STEP TECHNIQUES USED FOR SPRINT START IN A SIDEWAYS DIRECTION: WHICH IS SUPERIOR?

The purpose of this study was to determine which technique is superior to in a standing sprint start in a sideways direction: the false step or forward step technique. Nine males performed 5 m sprints in a rightward direction starting with these two techniques. They took a first step in their right side with their right foot in the forward step trials, whereas they took a first step in their left side with their left foot in the false step trials. No significant differences were found between the two trial conditions in the sprint times for 1 m, 2 m, 3 m and 4 m. These results indicate that the start techniques made no difference in the performance in the sideways direction, although the superiority of the false step technique for the forward sprint start was reported previously. This finding suggests that the superiority of the sprint start techniques is dependent on the sprint direction

Contact representation of short range correlation in light nuclei studied by the High-Momentum Antisymmetrized Molecular Dynamics

The high-momentum antisymmetrized molecular dynamics (HMAMD) is a new promising framework with significant analytical simplicity and efficiency inherited from its antisymmetrized molecular dynamics in describing the high momentum correlations in various nuclear states. In the aim of further improving the numerical efficiency for the description of nucleon-nucleon correlation, we introduce a new formulation by including a new Gaussian weighted basis of high momentum pairs in the HMAMD wave function, with which very rapid convergence is obtained in numerical calculation. It is surprising that the very high-momentum components in the new HMAMD basis are found to be almost equivalent to the contact representation of the nucleon-nucleon pairs with very small nucleon-nucleon distance. The explicit formulation for the contact term significantly improves the numerical efficiency of the HMAMD method, which shows the importance of the contact correlation in the formulation of light nuclei