Effects of multi- Λ hyperons on collective modes in nuclei
PHYSICAL REVIEW C, cilt.114, sa.024325, ss.1-12, 2026 (Hakemli Dergi)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 114 Sayı: 024325
- Basım Tarihi: 2026
- Doi Numarası: 10.1103/mg5m-b94l
- Dergi Adı: PHYSICAL REVIEW C
- Sayfa Sayıları: ss.1-12
- Yıldız Teknik Üniversitesi Adresli: Evet
Özet
The dynamical influence of $Λ$ hyperons on the excited-state properties of closed-shell multi-$Λ$ Ca, Ni, Sn and Pb hypernuclei is investigated using the self-consistent Hartree-Fock + Random Phase Approximation in coordinate space. The strength distributions for the isoscalar monopole, isovector dipole, and isoscalar quadrupole modes are calculated, revealing a systematic upward energy shift with increasing $Λ$ hyperon number $-S$. The scaling behavior of the computed centroid energies $\sqrt{m_1/m_{-1}}$ with respect to both the mass and hyperon number is determined. The nuclear incompressibility modulus $K_A$ is found to increase monotonically with $-S$. The largest value is found in the $^{258}_{50Λ}$Pb hypernucleus, reaching $K_A = 322 $ MeV. Calculations in uniform hypernuclear matter confirm that this stiffening is a bulk effect driven by both the $NΛ$ and $ΛΛ$ interactions. Analysis of the transition densities for states with maximal collective coherence indicates that the dynamical effect of $Λ$ hyperons is predominantly in phase with the protons, especially in the case of the isovector E1 modes.