arXiv subjects

Kai-Wen Kelvin-Lee

Publications and source records attributed to Kai-Wen Kelvin-Lee.

4 recordsLinked to original sources

arXiv2026

Scalar diquark mass and quark--diquark potential from lattice QCD using the potential method with a static quark

We study the scalar diquark mass and the quark--diquark potential by applying a HAL QCD-inspired potential method to a baryonic system composed of a scalar diquark and a static quark. The diquark mass is determined self-consistently by requiring that the p-wave baryonic spectrum obtained from two-point correlators be reproduced within the potential framework. Numerical calculations are performed using $2+1$ flavor QCD gauge configurations generated by the PACS-CS Collaboration on a $L^{3} \times T = 32^{3} \times 64$ lattice with $a^{-1} \approx 2.176$ GeV and the pion mass, $m_π \approx 702$ MeV. From the analysis, we obtain a scalar diquark mass which is close to the na\"ıve constituent quark estimate $ (2/3)m_{N}$, together with a quark--diquark potential of the Cornell type (Coulomb + linear). The string tension extracted from the quark--diquark potential agrees within approximately 5% with that obtained from the static quark--antiquark potential (Wilson Loop).

hep-lat↗

arXiv2026

Diquark mass and quark-diquark potential by lattice QCD using an extended HAL QCD method with a static quark

We will calculate the diquark mass together with the quark-diquark potential. We apply an extended HAL QCD potential method to a baryonic system made up from a static quark and a diquark. Numerical calculations are performed by employing 2+1 flavor QCD gaugeconfigurations generated by CP-PACS and JLQCD Collaborations on a $16^{3} \times 32$ lattice with $a^{-1} \approx 1.6$ GeV. To improve the statistical noise in the propagators of the static quark, the HYP smearing is employed on the gauge links. Two-point correlators of quark-diquark baryonic system are then computed to obtain their ground-state energies where various types of diquarks are considered (eg: scalar diquark, axial-vector diquark etc). We apply an extended HAL QCD method on a baryonic system made up from a scalar diquark and a static quark to study the scalar diquark mass and the quark-diquark potential. In order to determine the diquark mass self-consistently in this HALQCD method, we demand that the baryonic spectrum in the p-wave sector obtained from the two-point correlators should be reproduced by the potential obtained from the baryonic system in the s-wave sector. We obtain the scalar diquark mass of roughly $(2/3) m_{N}$ , i.e., twice the naïve estimates of a constituent quark mass together with the quark-diquark potential of Cornell type (Coulomb + linear).

hep-lat↗

arXiv2021

Role of tensor terms of the Skyrme energy-density functional on neutron deformed magic numbers in the rare-earth region

The role of the tensor part of the nuclear interaction is actively investigated in recent years due to experimental advancement yielding new data in nuclei far from the $β$-stability line. In this article we study the effect of this part of the nuclear interaction on deformed neutron magic numbers in the rare-earth region within the Skyrme energy-density functional for various TIJ \cite{lesinski:2007} parametrizations. Two quantities signaling magic numbers are considered: two-neutron separation energies and single-particle energies. They are calculated in isotopic series involving well-deformed rare-earth nuclei ranging from $Z=64$ to $Z=72$ in the $N=100$ region. Obtained results show that, whereas the neutron-proton tensor contribution to binding energies is important to reproduce neutron sub-shell closure at $N = 104$ in heavier rare earths Yb ($Z=70$) and Hf ($Z=72$) isotopes, like-particle tensor also plays a role in the single-particle spectrum around Fermi level and is even favored in lighter Gd ($Z=64$) and Dy ($Z=66$) rare-earth isotopes.

nucl-th↗

arXiv2019

Consistency of two different approaches to determine the strength of a pairing residual interaction in the rare-earth region

Two fits of the pairing residual interaction in the rare-earth region are independently performed. One is made on the odd-even staggering of masses by comparing measured and explicitly calculated three-point binding-energy differences centered on odd-even nuclei. Another deals with the moments of inertia of the first 2+ states of well deformed even-even nuclei upon comparing experimental data with the results of Inglis-Belyaev moments (supplemented by a crude estimate of the so-called Thouless-Valatin corrections). The sample includes 24 even-even and 31 odd-mass nuclei selected according to two criteria: they should have good rotor properties and should not correspond to low pairing-correlation regimes in their ground states. Calculations are performed in the self-consistent Hartree-Fock plus BCS framework (implementing a self-consistent blocking in the case of odd-mass nuclei). The Skyrme SIII parametrization is used in the particle-hole channel and the fitted quantities are the strengths of |Tz|=1 proton and neutron seniority residual interactions. As a result, the two fits yield sets of strengths in excellent agreement: about 0.1% for the neutron parameters and 0.2% for protons. In contrast when one performs such a fit on odd-even staggering from quantities deduced from BCS gaps or minimal quasiparticle energies in even-even nuclei, as is traditional, one obtains results significantly different from those obtained in the same nuclei by a fit of moments of inertia. As a conclusion, beyond providing a phenomenological tool for microscopic calculations in this region, we have illustrated the proposition made in the seminal paper of Bohr, Mottelson and Pines that moments of inertia and odd-even staggering in selected nuclei were excellent measuring sticks of nuclear pairing correlations.

nucl-th↗