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Myaing Thi Win

Publications and source records attributed to Myaing Thi Win.

3 recordsLinked to original sources

Shape of Lambda hypernuclei in (beta,gamma) deformation plane

We study the shape of $Λ$ hypernuclei in the full ($β,γ$) deformation plane, including both axially symmetric and triaxial quadrupole deformations. To this end, we use the constrained Skyrme Hartree-Fock+BCS method on the three-dimensional Cartesian mesh. The potential energy surface is analyzed for carbon hypernuclei as well as for sd-shell hypernuclei such as $^{27,29}_Λ$Si and $^{25,27}_Λ$Mg. We show that the potential energy surface in the ($β,γ$) plane is similar to each other between the hypernuclei and the corresponding core nuclei, although the addition of $Λ$ hyperon makes the energy surface somewhat softer along the $γ$ direction. Our calculation implies that the energy of the $γ$ vibration for $^{25,27}_Λ$Mg nuclei is lowered by about 0.15 MeV with respect to that of $^{24,26}$Mg nuclei.

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Deformation and weak decay of Lambda hypernuclei

We use the self-consistent mean-field theory to discuss the ground state and decay properties of $Λ$ hypernuclei. We first discuss the deformation of $Λ$ hypernuclei using the relativistic mean-field (RMF) approach. We show that, although most of hypernuclei have a similar deformation parameter to the core nucleus, the shape of $^{28}$Si is drastically altered, from oblately deformed to spherical, if a $Λ$ particle is added to this nucleus. We then discuss the pionic weak decay of neutron-rich $Λ$ hypernuclei using the Skyrme Hartree-Fock + BCS method. We show that, for a given isotope chain, the decay rate increases as a function of mass number, due to the strong neutron-proton interaction.

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Deformation of Lambda hypernuclei

We study the deformation property of $Λ$ hypernuclei using the relativistic mean field (RMF) method. We find that $^{29}_Λ$Si and $^{13}_Λ$C hypernuclei have spherical shape as a consequence of the additional $Λ$ particle, whereas the corresponding core nuclei, $^{28}$Si and $^{12}$C, are oblately deformed. Most of other hypernuclei have a similar deformation parameter to the core nucleus, in accordance with the previous study with the non-relativistic Skyrme-Hartree-Fock method. We discuss the sensitivity of our results to the choice of pairing interaction and to the parameter set of the RMF Lagrangian.

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