arXiv subjects

Thiri Yadanar Htun

Publications and source records attributed to Thiri Yadanar Htun.

3 recordsLinked to original sources

arXiv2022

Study on $Λnn$ Bound State and Resonance

We perform the ab initio no-core shell model (NCSM) calculation to investigate the bound state problem of the three-body $Λnn$ system in chiral next-to-next-to-leading-order NN and chiral leading-order YN interactions. The calculations show that no $Λnn$ bound state exists, but predict a low-lying $Λnn$ resonant state near the threshold with the energy of $E_r= 0.124$ MeV and the width of about $Γ=1.161$ MeV. In searching for $Λnn$ resonances, we extend the NCSM calculation to the continuum state by employing the J-matrix formalism in the scattering theory with the hyperspherical oscillator basis.

nucl-th↗

arXiv2022

A possible interpretation of $Λ$ baryon spectrum with pentaquark components

The $Λ$ baryon spectrum is studied within the SU(3) flavor symmetry in a constituent quark model. We found that it is rather difficult to accommodate some negative-parity $Λ$ resonances as single $q^2s$ ($q = u,\,d$ quarks) states in the conventional three-quark picture. The ground $q^3s\bar q$ pentaquark mass spectrum is evaluated and a possible interpretation is proposed in the work: the observed $Λ(1405)1/2^{-}$, $Λ(1670)1/2^{-}$ and $Λ(1800)1/2^{-}$ are three-state mixtures of two $p$-wave $q^2s$ states and one ground $q^3s\bar q$ pentaquark state, so are the $Λ(1520)3/2^{-}$, $Λ(1690)3/2^{-}$ and $Λ(2050)3/2^{-}$ resonances.

hep-ph↗

arXiv2021

Systematic Nuclear Uncertainties in the Hypertriton System

The hypertriton bound state is relevant for inference of knowledge about the hyperon-nucleon (YN) interaction. In this work we compute the binding energy of the hypertriton using the ab initio hypernuclear no-core shell model (NCSM) with realistic interactions derived from chiral effective field theory. In particular, we employ a large family of nucleon-nucleon interactions with the aim to quantify the theoretical precision of predicted hypernuclear observables arising from nuclear-physics uncertainties. The three-body calculations are performed in a relative Jacobi-coordinate harmonic oscillator basis and we implement infrared correction formulas to extrapolate the NCSM results to infinite model space. We find that the spread of the predicted hypertriton binding energy, attributed to the nuclear-interaction model uncertainty, is about 100 keV. In conclusion, the sensitivity of the hypertriton binding energy to nuclear-physics uncertainties is of the same order of magnitude as experimental uncertainties such that this bound-state observable can be used in the calibration procedure to constrain the YN interactions.

nucl-th↗