arXiv subjects

Mohammad Mehdi Firoozabadi

Publications and source records attributed to Mohammad Mehdi Firoozabadi.

3 recordsLinked to original sources

arXiv2021

$Ω$-deuteron Interaction in Folding Model

A simple single folding model for $Ω$-deuteron with maximal spin $\left(I\right)J^{P}=\left(0\right)5/2^{+}$ is investigated. $Ω$ is assumed to orbit an unperturbed deuteron in a $Ω$-deuteron potential based on a separable $Ω$-nucleon potential from lattice QCD. We show that the effective central folding potential of $Ωd$ in the $^{5}S_{2}$ channel has a simple Wood-Saxon form, and approximate the upper bound for the binding energy of $Ω$ particle on a deuteron. In order to investigate how changes in the wave functions affect the results, we consider four analytical forms for $S$-state deuteron wave functions, i.e., two widely used Hulthén forms, as well as the modified Reid93 and Argonne v18 forms. Our calculations of binding energy from simple two-body approximation are compared with the results reported for the three-body problem; it is confirmed that the $Ωd$ system is deeply bound. Although the single folding model reduces the three-body problem to a two-body problem, this simplification is inadequate.

nucl-th↗

arXiv2020

Simple Woods-Saxon type form for $Ωα$ and $Ξα$ interactions using Folding Model

We derive a simple Woods-Saxon type form for the potentials between $Y=Ξ, Ω$ and $α$ by using a single-folding potential method, based on a separable $Y$-nucleon potential. Accordingly, the potentials $Ξ+α$ and $Ω+α$ are obtained using the ESC08c Nijmegens $ΞN$ potential (in $^{3}S_{1}$ channel) and HAL QCD Collaboration $ΩN$ interactions (in lattice QCD), respectively. In deriving the potential between $Y$ and $α$, the same potential between $Y$ and $N$ is used. Binding energy, scattering length and effective range of $Y$ particle on the alpha particle are approximated by the resultant potentials. The depths of the potentials in $Ωα$ and $Ξα$ systems are obtained $-61$ and $-24.4$ MeV, respectively. In the case of $Ξα$ potential, a fairly good agreement is observed between the single-folding potential method and the phenomenological potential of Dover-Gal model. These potentials can be used in 3-,4- and 5-body cluster structures of $ Ω$ and $Ξ$ hypernuclei.

nucl-th↗

arXiv2017

Constrained Path Monte Carlo method for spin $ 1/2 $ fermions at unitarity limit

We present calculations for spin $ 1/2 $ fermions at unitarity limit, where the effective range of the interaction is zero and the scattering length is infinite. We compute the ground-state energy for a system of 6, 10,14,18 and 20 particles, with equal numbers of up and down spins in a periodic cube in the full ground-state constrained-path Monte Carlo (CPMC) method using the extended, attractive Hubbard model. Our results in a careful extrapolation to the thermodynamic limit may suggest that the ratio of the ground-state energy to that of a free Fermi gas is $ ξ= 0.43(4) $, which can compare with recent experimental results and consistent with the fixed node Green's function Monte Carlo and novel lattice approaches results. We also obtain results for interactions with different effective ranges and find that the energy is consistent with a universal linear dependence on the product of the Fermi momentum and the effective range.

cond-mat.str-el↗