Nuclear Theory·nucl-th

Friday·April 14, 2023

10 papers—6 primary·4 cross-listed

01
Four-Body Systems at Large Cutoffs in Effective Field Theory
Xincheng Lin
Four-body systems are studied using an effective field theory with two- and three-body contact interactions. A method to systematically address deep trimers (three-body bound states that are more tightly bound than four-body bound/resonant states) in four-body calculations is developed using a diagrammatic approach. Previous calculations were limited by the existence of deep trimers, which this work overcomes. For cold $^{4}$ He atoms, binding energies of 526.1(5)~mK and 128.517(1)~mK are obtained at leading order for the tetramer ground and excited states, respectively, where errors come from the truncation of three-body partial waves. Tetramer binding energies and decay widths are also computed approaching the unitary limit. In the unitary limit, there are two tetramers associated with each trimer of binding energy $B_{3}^{(0)}$ . The binding energy and decay width for the associated tetramer ground state are $E_{4}^{(0)} = 4.60 (1) B_{3}^{(0)}$ and $Γ_{4}^{(0)} /2 = 0.0160 (1) B_{3}^{(0)}$ , respectively, and for the associated tetramer excited state, $E_{4}^{(1)} = 1.0022 (3) B_{3}^{(0)}$ and $Γ_{4}^{(1)} /2 = 2.57 (2) \times 1 0^{- 4} B_{3}^{(0)}$ , respectively. This calculation is a gateway to higher-order and/or more-body calculations in nuclear and atomic systems.
nucl-thPRC(2024)·3 citations
02
A generalized hydrodynamizing initial stage for Heavy Ion Collisions
Govert Nijs🇺🇸 · Wilke van der Schee🇨🇭
We present an extended Bayesian analysis using Trajectum where the initial condition can now include binary scaling. For the far-from-equilibrium evolution before hydrodynamics we introduce an interpolation between free streaming and a holographically inspired evolution that exhibits fast hydrodynamization. We find strong evidence that binary scaling is incompatible with experimental data and find evidence that the holographic far-from-equilibrium evolution is preferred. We end with a discussion on several changes and improvements in the Bayesian framework.
nucl-thhep-phnucl-ex30 citations
03
Enlarged deformation region in neutron-rich Zr isotopes by the second intruder orbit
W. Horiuchi · T. Inakura · S. Michimasa · M. Tanaka
Nuclear deformations and density profiles of neutron-rich even-even Zr isotopes are investigated using the Skyrme-Hartree-Fock-Bogoliubov method. Large quadrupole and hexadecapole deformations are predicted along with large enhancement of the total reaction cross sections at the neutron number $N = 60$ -74. Strong nuclear deformation starting at $N = 60$ is induced by the occupation of the intruder orbit with the asymptotic quantum number $[n n_{z} Λ] Ω$ = [550]1/2 originating from the spherical $0 h_{11/2}$ orbit. The deformation region is further enlarged from $N = 72$ to 74 owing to the occupation of the next intruder orbit with [530]1/2 originating from the spherical $1 f_{7/2}$ orbit. This characteristic nuclear deformation is crucially reflected in the systematic behavior of the nuclear radii and the density profiles near the nuclear surface.
nucl-thPRC(2023)·6 citations
04
Faddeev Calculation of $_{Λ}^{3}$ H incorporating 2{\pi}-exchange $Λ$ NN Interaction
H. Kamada🇯🇵 · M. Kohno🇯🇵 · K. Miyagawa🇯🇵
Faddeev calculations of hypertriton ( $_{Λ}^{3}$ H) separation energy are performed, incorporating $2 π$ -exchange $Λ$ NN three-baryon force. Repulsive contributions of the three-baryon force in the order of 20 keV are found, depending on the NN interactions employed. The effect is not negligible compared with the small separation-energy of $_{Λ}^{3}$ H.
nucl-thnucl-exPRC(2023)·9 citations
05
Least action description of dynamic pairing correlations in the fission of Curium and Californium isotopes based on the Gogny energy density functional
R. Rodriguez-Guzman · L.M. Robledo · C.A. Jimenez-Hoyos · N. C. Hernandez
The impact of dynamic pairing correlations and their interplay with Coulomb antipairing effects on the systematic of the spontaneous fission half-lives for the nuclei $^{240 - 250}$ Cm and $^{240 - 250}$ Cf is analyzed, using a hierarchy of approximations based on the parametrization D1M of the Gogny energy density functional (EDF). First, the constrained Hartree-Fock-Bogoliubov (HFB) approximation is used to compute deformed mean-field configurations, zero-point quantum corrections and collective inertias either by using the Slater approximation to Coulomb exchange and neglecting Coulomb antipairing or by fully considering the exchange and pairing channels of the Coulomb interaction. Next, the properties of the {\it{least action}} and {\it{least energy}} fission paths are compared. In the {\it{least action}} case, pairing is identified as the relevant degree of freedom in order to minimize the action entering the Wentzel-Kramers-Brillouin (WKB) approximation to the tunneling probability through the fission barrier. Irrespective of the treatment of Coulomb exchange and antipairing, it is shown that the {\it{least action}} path obtained taking into account the pairing degree of freedom leads to stronger pairing correlations that significantly reduce the spontaneous fission half-lives $t_{S F}$ improving thereby the comparison with the experiment by several orders of magnitude. It is also shown that the Coulomb antipairing effect is, to a large extent, washed out by the {\it{least action}} procedure and therefore the $t_{S F}$ values obtained by the two different treatments of the Coulomb exchange and pairing are of similar quality.
nucl-thPRC(2023)·8 citations
06
Hyperspherical cluster model for bosons: application to sub-threshold halo states in helium drops
N.K. Timofeyuk
To describe long-range behaviour of one particle removed from a few- or a many-body system, a hyperspherical cluster model has been developed. It has been applied to the ground and first excited states of helium drops with five, six, eight and ten atoms interacting via a two-body soft gaussian potential. Convergence of the hyperspherical cluster harmonics expansion is studied for binding energies, root-mean-squared radii and overlaps of the wave functions of two helium drops differing by one atom. It was shown that with increasing model space the functional form of such overlaps at large distances converges to the correct asymptotic behaviour. The asymptotic normalization coefficients that quantify the overlaps' amplitudes in this region are calculated. It was also shown that in the first excited state one helium atom stays far apart from the rest forming a two-body molecule, or a halo. The probability of finding the halo atom in the classically-forbidden region of space depends on the definition of the latter and on the number of atoms in the drop. The total norm of the overlap integrals, the spectroscopic factor, represents the number of partitions of a many-body state into a chosen state of the system with one particle removed. The spectroscopic factors have been calculated and their sum rules are discussed giving a further insight into the structure of helium drops.
nucl-thcond-mat.quant-gasphysics.atm-clusphysics.atom-ph+1Few Body Syst.(2023)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Four-Body Systems at Large Cutoffs in Effective Field Theory

A generalized hydrodynamizing initial stage for Heavy Ion Collisions

Enlarged deformation region in neutron-rich Zr isotopes by the second intruder orbit

Faddeev Calculation of Λ3​H incorporating 2{\pi}-exchange ΛNN Interaction

Least action description of dynamic pairing correlations in the fission of Curium and Californium isotopes based on the Gogny energy density functional

Hyperspherical cluster model for bosons: application to sub-threshold halo states in helium drops

Affiliations

Faddeev Calculation of $_{Λ}^{3}$ H incorporating 2{\pi}-exchange $Λ$ NN Interaction