Nuclear Theory·nucl-th

Friday·November 5, 2021

7 papers—4 primary·3 cross-listed

01
Three-dimensional Skyrme Hartree-Fock-Bogoliubov solver in coordinate-space representation
Mengzhi Chen · Tong Li · Bastian Schuetrumpf · Paul-Gerhard Reinhard · Witold Nazarewicz
The coordinate-space representation of the Hartree-Fock-Bogoliubov theory is the method of choice to study weakly bound nuclei whose properties are affected by the quasiparticle continuum space. To describe such systems, we developed a three-dimensional Skyrme-Hartree-Fock-Bogoliubov solver HFBFFT based on the existing, highly optimized and parallelized Skyrme-Hartree-Fock code Sky3D. The code does not impose any self-consistent spatial symmetries such as mirror inversions or parity. The underlying equations are solved in HFBFFT directly in the canonical basis using the fast Fourier transform. To remedy the problems with pairing collapse, we implemented the soft energy cutoff and pairing annealing. The convergence of HFB solutions was improved by a sub-iteration method. The Hermiticity violation of differential operators brought by Fourier-transform-based differentiation has also been solved. The accuracy and performance of HFBFFT were tested by benchmarking it against other HFB codes, both spherical and deformed, for a set of nuclei, both well-bound and weakly-bound.
nucl-thComput.Phys.Commun.(2022)·14 citations
02
Stochastic features of dissipative large-amplitude dynamics and nuclear fission
V.M.Kolomietz · S.V.Radionov
Within a density matrix approach for nuclear many--body system, it is derived non--Markovian Langevin equations of motion for nuclear collective parameters, where memory effects are defined by memory time. The developed stochastic approach is applied to study both the nuclear descent from fission barrier to a scission point and thermal diffusive overcoming of the barrier. The present paper is partly a review of our results obtained earlier and contains new results on the non--Markovian generalization of Kramers' theory of escape rate and on time features of the collective dynamics in the presence of periodic external modulation.
nucl-th0 citations
03
Analysis of the fusion mechanism in synthesis superheavy element 119 via $^{54}$ Cr+ $^{243}$ Am reaction
B.M. Kayumov (1,4) · O.K. Ganiev (1,2,5) · A.K. Nasirov (1,3) · G.A. Yuldasheva (1) ((1) Institute of Nuclear Physics, Uzbekistan Academy of Science, Tashkent, Uzbekistan, (2) College of Engineering, Akfa University, Tashkent, Uzbekistan, (3) Joint Institute for Nuclear Research, Dubna, Russia, (4) New Uzbekistan University, Tashkent, Uzbekistan, (5) Faculty of Physics, National University of Uzbekistan, Tashkent)
The combined dinuclear system (DNS) and statistical model implanted in KEWPIE2 have been used to study the prospects for the synthesis of a superheavy element (SHE) with $Z = 119$ in the $^{54}$ Cr+ $^{243}$ Am fusion reaction. The method of calculation has been verified by description of the evaporation residue cross sections measured for the $^{48}$ Ca+ $^{243}$ Am reaction. The calculated results of the partial and total cross sections for the complete fusion, quasifission, fast fission and evaporation residues formation for both reactions are discussed.
nucl-thPRC(2022)·34 citations
04
Constraining the nucleon size with relativistic nuclear collisions
Giuliano Giacalone🇩🇪 · Björn Schenke🇺🇸 · Chun Shen🇺🇸
The notion of the "size" of nucleons and their constituents plays a pivotal role in the current paradigm of the formation and the fluctuations of the quark-gluon plasma produced in high-energy nuclear collision experiments. We report on state-of-the-art hydrodynamic results showing that the correlation between anisotropic flow, $v_{n}^{2}$ , and the mean transverse momentum of hadrons, $[p_{t}]$ , possesses a unique sensitivity to the nucleon size in off-central heavy-ion collisions. We argue that existing experimental measurements of this observable support a picture where the relevant length scale characterizing the colliding nucleons is of order 0.5 fm or smaller, and we discuss the broad implications of this finding for future global Bayesian analyses aimed at extracting initial-state and medium properties from nucleus-nucleus collision data, including $v_{n}^{2}$ - $[p_{t}]$ correlations. Determinations of the nucleon size in heavy-ion collisions will provide a solid independent constraint on the initial state of small system collisions, and will establish a deep connection between collective flow data in nucleus-nucleus experiments and data on deep inelastic scattering on protons and nuclei.
nucl-thhep-exhep-phnucl-exPRL(2022)·43 citations
05
Patterns of $C$ - and $C P$ -violation in hadronic $η$ and $η^{'}$ three-body decays
Hakan Akdag🇩🇪 · Tobias Isken🇩🇪 · Bastian Kubis🇩🇪
We construct hadronic amplitudes for the three-body decays $η^{(')} \to π^{+} π^{-} π^{0}$ and $η^{'} \to η π^{+} π^{-}$ in a non-perturbative fashion, allowing for $C$ - and $C P$ -violating asymmetries in the $π^{+} π^{-}$ distributions. These amplitudes are consistent with the constraints of analyticity and unitarity. We find that the currently most accurate Dalitz-plot distributions taken by the KLOE-2 and BESIII collaborations confine the patterns of these asymmetries to a relative per mille level. Our dispersive representation allows us to extract the individual coupling strengths of the $C$ - and $C P$ -violating contributions arising from effective isoscalar and isotensor operators in $η^{(')} \to π^{+} π^{-} π^{0}$ and an effective isovector operator in $η^{'} \to η π^{+} π^{-}$ , while the strongly different sensitivities to these operators can be understood from chiral power counting arguments.
↳ hep-phhep-exnucl-thJHEP(2022)·27 citations
06
Neutrino Interactions with Matter and the MiniBooNE anomaly
Luis Alvarez-Ruso🇪🇸 · Eduardo Saul-Sala🇪🇸
The excess of electron-like events measured by MiniBooNE challenges our understanding of neutrinos and their interactions. We review the status of this open problem and ongoing efforts to resolve it. After introducing the experiment and its results, we consider the main experimental backgrounds and the related physics of neutrino interactions with matter such as quasielastic-like scattering and weak pion production on nucleons and nuclei. Special attention is paid to single photon emission in neutral current interactions and, in particular, its coherent channel. The difficulties to reconcile the MiniBooNE anomaly with global oscillation analysis is then highlighted. We finally outline some of the proposed solutions of the puzzle involving unconventional neutrino-interaction mechanisms.
↳ hep-phhep-exnucl-thEur.Phys.J.ST(2021)·27 citations
07
Nuclear two point correlation functions on a quantum-computer
Alessandro Baroni🇺🇸 · Joseph Carlson🇺🇸 · Rajan Gupta🇺🇸 · Andy C. Y. Li🇺🇸 · Gabriel N. Perdue🇺🇸 · Alessandro Roggero🇮🇹
The calculation of dynamic response functions is expected to be an early application benefiting from rapidly developing quantum hardware resources. The ability to calculate real-time quantities of strongly-correlated quantum systems is one of the most exciting applications that can easily reach beyond the capabilities of traditional classical hardware. Response functions of fermionic systems at moderate momenta and energies corresponding roughly to the Fermi energy of the system are a potential early application because the relevant operators are nearly local and the energies can be resolved in moderately short real time, reducing the spatial resolution and gate depth required. This is particularly the case in quasielastic electron and neutrino scattering from nuclei, a topic of great interest in the nuclear and particle physics communities and directly related to experiments designed to probe neutrino properties. In this work we use current quantum hardware and error mitigation protocols to calculate response functions for a highly simplified nuclear model through calculations of a 2-point real time correlation function for a modified Fermi-Hubbard model in two dimensions with three distinguishable nucleons on four lattice sites.
↳ quant-phhep-latnucl-thPRD(2022)·41 citations

Affiliations

first authorsco-authorsvia INSPIRE

Three-dimensional Skyrme Hartree-Fock-Bogoliubov solver in coordinate-space representation

Stochastic features of dissipative large-amplitude dynamics and nuclear fission

Analysis of the fusion mechanism in synthesis superheavy element 119 via 54Cr+243Am reaction

Constraining the nucleon size with relativistic nuclear collisions

Patterns of C- and CP-violation in hadronic η and η′ three-body decays

Neutrino Interactions with Matter and the MiniBooNE anomaly

Nuclear two point correlation functions on a quantum-computer

Affiliations

Analysis of the fusion mechanism in synthesis superheavy element 119 via $^{54}$ Cr+ $^{243}$ Am reaction

Patterns of $C$ - and $C P$ -violation in hadronic $η$ and $η^{'}$ three-body decays