Application of random phase approximation to vibrational excitations of double-$\Lambda$ hypernuclei

Abstract

Using the Hartree-Fock plus random-phase-approximation (HF+RPA), we study the impurity effect of $\Lambda$ hyperon on the collective vibrational excitations of double-$\Lambda$ hypernuclei. To this end, we employ a Skyrme-type $\Lambda N$ and $\Lambda \Lambda$ interactions for the HF calculations, and the residual interactions for RPA derived with the same interactions. We find that inclusion of two $\Lambda$ hyperons in ${}^{16}$O shifts the energy of the collective states towards higher energies. In particular, the energy of the giant monopole resonance of ${}_{\Lambda \Lambda }^{18}$O, as well as that of ${}_{\Lambda \Lambda }^{210}$Pb, becomes larger. This implies that the effective incompressibility modulus increases due to the impurity effect of $\Lambda$ particle, if the $\beta$-stability condition is not imposed.

11 pages, 7 figures, 2 tables

References in corpus (12)

• Isotopic dependence of the giant monopole resonance in the even-A ^{112-124}Sn isotopes and the asymmetry term in nuclear incompressibility
• Incompressibility of neutron-rich matter
• Isoscalar giant resonances in the Sn nuclei and implications for the asymmetry term in the nuclear-matter incompressibility
• Deformation of Lambda hypernuclei
• Deformation of hypernuclei studied with antisymmetirzed molecular dynamics
• Five-body cluster structure of double-$\Lambda$ hypernucleus ${}_{\Lambda \Lambda }^{11}$Be
• Shape of Lambda hypernuclei in (beta,gamma) deformation plane
• The role of superfluidity in nuclear incompressibilities
• Di-neutron clustering and deuteron-like tensor correlation in nuclear structure focusing on 11Li
• On the Density Dependent Nuclear Matter Compressibility
• The $\Lambda$-$\Sigma$ coupling effect in the neutron-rich $\Lambda$-hypernucleus ${}_{\Lambda }^{10}$Li by microscopic shell model
• A particle-hole model approach for hypernuclei

Cited by in corpus (8)

• Clusterization and deformation of multi-$\Lambda$ hypernuclei within relativistic mean-field model
• Density Functional approach for multi-strange hypernuclei: competition between $\Lambda$ and ${\Xi }^{0,-}$ hyperons
• Collective excitations of $\Lambda$ hypernuclei
• Effects of ground-state correlations on collective excitations of ${}^{16}$O
• Impurity effect of Lambda particle on the structure of 18F and 19F_Lambda
• Sum rule approach to a soft dipole mode in $\Lambda$ hypernuclei
• Quest for magicity in hypernuclei
• Reaction cross sections of hypernuclei and the shrinkage effect