Nuclear Theory·nucl-th

Thursday·December 5, 2019

8 papers—6 primary·2 cross-listed

01
[Submitted on 4 Dec 2019]
$β$ decay of odd-A nuclei with the interacting boson-fermion model based on the Gogny energy density functional
K. Nomura🇭🇷 · R. Rodríguez-Guzmán🇰🇼 · L. M. Robledo🇪🇸
The low-energy excitations and $β$ decays of odd-A nuclei are studied within the interacting boson-fermion model (IBFM), based on the Gogny-D1M nuclear energy density functional (EDF). The constrained Hartree-Fock-Bogoliubov (HFB) approximation is employed to compute potential energy surfaces in terms of triaxial quadrupole degrees of freedom for even-even Xe and Ba nuclei in the mass $A \approx 130$ region. The mean field approximation also provides spherical single-particle energies and occupation probabilities for the neighboring odd-A nuclei. Those quantities represent a microscopic input for spectroscopic calculations in odd-A Xe and Ba, Cs and La isotopes. The Gamow-Teller (GT) and Fermi (F) transition matrix elements, needed to compute $β$ -decay $lo g f t$ values are obtained without any phenomenological fitting. It is shown that both the low-lying states and $β$ decays of the studied odd-A systems are described reasonably well within the employed theoretical framework.
Comments:
15 pages, 8 figures, 6 tables; to be published in Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1912.01846 [pdf]
PRC(2020)·18 citations
02
[Submitted on 4 Dec 2019]
Three-body resonant states of $_{Λ}^{9}$ Be with $α + α + Λ$ cluster model
Qian Wu🇨🇳 · Yasuro Funaki🇯🇵 · Emiko Hiyama🇯🇵 · Hongshi Zong🇨🇳
We study the structure of $_{Λ}^{9}$ Be in the framework of three body $α + α + Λ$ cluster model using YNG-NF interaction with the Gaussian expansion method. Employing the complex scaling method, we obtain the energies of bound states as well as energies and decay widths of the resonant states. By analyzing our wave functions of bound states and resonant states, we confirm three analogue states of $_{Λ}^{9}$ Be pointed out by Band $o ˉ$ and Motoba {\it et al.} \cite{motoba1983,motoba1985,bando1983}, $^{8}$ Be analogue states, $_{Λ}^{9}$ Be genuine states and $^{9}$ Be analogue states. The new states of $_{Λ}^{9}$ Be are also obtained at a high energy region with broader decay widths.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1912.01859 [pdf]
PRC(2020)·10 citations
03
[Submitted on 4 Dec 2019]
Electromagnetic transitions in near-threshold resonances
J. Okołowicz🇵🇱 · M. Płoszajczak🇫🇷
Near-threshold collectivization of continuum shell model eigenstates is investigated in $^{20}$ O on the example of B(E $λ$ ) decays of 4 $^{+}$ states in the vicinity of elastic and inelastic neutron threshold. Changes of the electromagnetic transition probabilities as a function of the continuum-coupling strength are explained by the corresponding evolution of the double poles of the scattering matrix.
Comments:
10 pages, 5 figures, Invited presentation at the XXXVI Mazurian Lakes Conference on Physics, September 1-7, 2019, Piaski, Poland
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1912.01935 [pdf]
Acta Phys.Polon.B(2020)·2 citations
04
[Submitted on 4 Dec 2019]
Heavy-Light Mesons on the Light Front
Shuo Tang🇺🇸 · Yang Li🇺🇸 · Pieter Maris🇺🇸 · James P. Vary🇺🇸
We study the heavy-light mesons within basis light-front quantization. The resulting mass spectra of $D$ , $D_{s}$ , $B$ , and $B_{s}$ agree reasonably well with experiments. We also predict states which could be measured in the near future. In the light-front formalism, we calculate the light-front wave functions and additional experimental observables, such as parton distribution functions, distribution amplitudes, and decay constants by means of integrations over light-front wave functions. We also provide ratios of decay constants for selected pseudoscalar meson decays ( $D_{s}$ to $D$ and $B_{s}$ to $B$ ) as they may prove to be theoretically more robust and more reliably determined in experiments. We find that our ratios are systematically smaller than existing experiment and other approaches by $5 - 18%$ .
Comments:
15 pages, 19 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1912.02088 [pdf]
EPJC(2020)·55 citations
05
[Submitted on 4 Dec 2019]
Heavy quark flow as better probes of QGP properties
Zi-Wei Lin🇨🇳 · Hanlin Li🇨🇳 · Fuqiang Wang🇺🇸
In earlier studies we have proposed that most parton $v_{2}$ comes from the anisotropic escape of partons, not from the hydrodynamic flow, even for semi-central Au+Au collisions at $s_{N N} = 200$ GeV. Here we study the flavor dependence of this escape mechanism with a multi-phase transport model. In contrast to naive expectations, we find that the charm $v_{2}$ is much more sensitive to the hydrodynamic flow than the lighter quark $v_{2}$ , and the fraction of $v_{2}$ from the escape mechanism decreases strongly with the quark mass for large collision systems. We also find that the light quark collective flow is essential for the charm quark $v_{2}$ . Our finding thus suggests that heavy quark flows are better probes of the quark-gluon-plasma properties than light quark flows.
Comments:
4 pages, 3 figures, 1 table. Contribution to the proceedings of the 17th International Conference on Strangeness in Quark Matter (SQM 2017), July 10-15, 2017, Utrecht, the Netherlands
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1912.02115 [pdf]
EPJ Web Conf.(2018)·3 citations
06
[Submitted on 4 Dec 2019]
Algebraic Gorkov solution in finite systems for the separable pairing interaction
R. M. Id Betan · C. E. Repetto
An algebraic Quantum Field Theory formulation of separable pairing interaction for spherical finite systems is presented. The Lipkin formulation of the model Hamiltonian and model wave function is used. The Green function technique is applied to obtain the model energy through the spectral function. Closed equation for the many-body energy of the system is given and comparison with exact models are performed.
Comments:
18 pages for the body document + 6 pages for two appendixes. 2 figures. 46 references
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1912.02146 [pdf]
NPA(2020)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

β decay of odd-A nuclei with the interacting boson-fermion model based on the Gogny energy density functional

Three-body resonant states of Λ9​Be with α+α+Λ cluster model

Electromagnetic transitions in near-threshold resonances

Heavy-Light Mesons on the Light Front

Heavy quark flow as better probes of QGP properties

Algebraic Gorkov solution in finite systems for the separable pairing interaction

Affiliations

$β$ decay of odd-A nuclei with the interacting boson-fermion model based on the Gogny energy density functional

Three-body resonant states of $_{Λ}^{9}$ Be with $α + α + Λ$ cluster model