arXiv subjects

E. Hiyama

Publications and source records attributed to E. Hiyama.

40 records · Page 3Linked to original sources

arXiv2001

`` $Λ- Σ$ conversion in $^4_Λ$He and $^4_Λ$H based on four-body calculation

Precise four-body calculations for $^4_Λ$He and $^4_Λ$H have been performed in the framework of the variational method with Jacobian-coordinate Gaussian-basis functions. All the rearrangement channels of both $NNN Λ$ and $NNN Σ$ are explicitly taken into account for the first time with the use of realistic $NN$ and $YN$ interactions. The role of $Λ$-$Σ$ conversion and the amount of the virtual $Σ$-component in $^4_Λ$He and $^4_Λ$H are discussed.

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arXiv2001

Benchmark Test Calculation of a Four-Nucleon Bound State

In the past, several efficient methods have been developed to solve the Schroedinger equation for four-nucleon bound states accurately. These are the Faddeev-Yakubovsky, the coupled-rearrangement-channel Gaussian-basis variational, the stochastic variational, the hyperspherical variational, the Green's function Monte Carlo, the no-core shell model and the effective interaction hyperspherical harmonic methods. In this article we compare the energy eigenvalue results and some wave function properties using the realistic AV8' NN interaction. The results of all schemes agree very well showing the high accuracy of our present ability to calculate the four-nucleon bound state.

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arXiv2000

Roles of quark-pair correlations in baryon structure and non-leptonic weak transitions of hyperon

Roles of quark-pair correlations in the baryon structure and the hyperon non-leptonic weak decay are studied within the non-relativistic constituent quark model. We construct the SU(3) ground state baryons by solving the three body problem rigorously with the confinement force and the short range spin-dependent attraction. We emphasize the importance of the $s=0$ quark-quark correlation to reproduce the $ΔI=1/2$ enhancement of the hyperon decay, and demonstrate that resulting static properties as well as the decay amplitudes agree with the experiments, if we deal with the $s=0$ correlation properly. Special attention is also put on the consequences of the SU(6) spin-flavor symmetry breaking due to the $s=0$ correlation. Calculated magnetic moments are the almost same as the naive SU(6) predictions in spite of the existence of the strong correlations.

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arXiv1999

Constituent quark model for baryons with strong quark-pair correlations and non-leptonic weak transitions of hyperon

We study the roles of quark-pair correlations for baryon properties, in particular on non-leptonic weak decay of hyperons. We construct the quark wave function of baryons by solving the three body problem explicitly with confinement force and the short range attraction for a pair of quarks with their total spin being 0. We show that the existence of the strong quark-quark correlations enhances the non-leptonic transition amplitudes which is consistent with the data, while the baryon masses and radii are kept to the experiment.

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