Nuclear Theory·nucl-th

Thursday·August 10, 2023

10 papers—3 primary·7 cross-listed

01
[Submitted on 8 Aug 2023]
Simulation of the 2E Technique on neutron multiplicity measurement as a function of fragment mass in spontaneous fission of 252Cf
Modesto Montoya
A Monte Carlo simulation algorithm to investigate the measurement of the average prompt neutron multiplicity as a function of pre-neutron mass, for fragments from the spontaneous fission of 252Cf is presented. The input data consist of experimental measurements of the kinetic energy and mass distributions obtained by Gook et al. and the values calculated using the FIFRELIN model by Piau et al. We analyze the output curve obtained by simulation of the 2E technique, which should ideally match the theoretical curve. However, we find that the simulated as experiential curve exhibits a maximum value at A=122, close to mass symmetry, while the pre-neutron curve has a maximum at A=118. Additionally, we observe that que the simulated as pre neutron values are higher than the theoretical values for A<90 and A>162, respectively. We attribute this discrepancy to inaccuracies in the relationship between provisional mass and the pre-neutron mass used in the 2E technique for data processing in each fission event.
Comments:
6 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2308.04550 [pdf]
Rev.Mex.Fis.(2024)·0 citations
02
[Submitted on 9 Aug 2023]
Beyond-mean-field description of octupolarity in dysprosium isotopes with the Gogny-D1M energy density functional
R. Rodriguez-Guzman · L. M. Robledo
The emergence and stability of (static) octupole deformation effects in Dy isotopes from dripline to dripline ( $72 \leq N \leq 142$ ) is analyzed in this paper using mean-field and beyond-mean-field techniques often used for this purpose. We find static octupole deformations at the Hartree-Fock-Bogoliubov (HFB) level with the Gogny D1M force for $N \approx 134$ isotopes, while nuclei with $N \approx 88$ exhibit reflection-symmetric ground states. It is shown that, given the softness found in the mean-field and parity-projected potential energy surfaces along the octupole direction, neither of these two levels of approximation is suficcient to extract conclusions about the (permanent and/or vibrational) nature of octupole dynamic in Dy isotopes. From the analysis of the collective wave functions as well as the excitation energies of the first negative-parity states and $B (E 3)$ strengths, obtained within the framework of a two-dimensional symmetry-conserving generator coordinate method (2D-GCM), it is concluded that the increased octupole collectivity in Dy isotopes with $N \approx 88$ and $N \approx 134$ is a vibrational-like effect that is not directly related to permanent mean-field octupole deformation in the considered nuclei. A pronounced suppression of the $B (E 1)$ strengths is predicted for isotopes with $N \approx 82$ and $N \approx 126$ . The comparison of results obtained with other parametrizations, show the robustness of the predicted trends with respect to the underlying Gogny energy density functional.
Comments:
13 pages, 7 figures, published in Phys Rev C. arXiv admin note: text overlap with arXiv:2104.08063
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2308.04784 [pdf]
PRC(2023)·11 citations
03
[Submitted on 9 Aug 2023]
A novel approach to light cluster production in heavy-ion collisions
Hui-Gan Cheng🇨🇳 · Zhao-Qing Feng🇨🇳
The issue of cluster production in heavy-ion collisions is addressed in a new manner, by implementing cluster correlation into the quantum molecular dynamics (QMD) transport model. We demonstrate for the first time, the good potentialities of this popular transport approach in the description of light cluster production including the deuteron, triton, $^{3}$ He and $α$ particle in heavy-ion collisions at intermediate energies. Both the INDRA and FOPI experimental data of the total multiplicities of light clusters and the charge distributions of heavier fragments are reasonably reproduced by the unified approach. The effects of both the cluster binding energies and the pauli repulsion are also shown to play crucial roles in the production of clusters.
Comments:
8 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2308.04852 [pdf]
PRC(2024)·12 citations
04
[Submitted on 8 Aug 2023] (cross-list from quant-ph)
Scalable Circuits for Preparing Ground States on Digital Quantum Computers: The Schwinger Model Vacuum on 100 Qubits
Roland C. Farrell🇺🇸 · Marc Illa🇺🇸 · Anthony N. Ciavarella🇺🇸 · Martin J. Savage🇺🇸
The vacuum of the lattice Schwinger model is prepared on up to 100 qubits of IBM's Eagle-processor quantum computers. A new algorithm to prepare the ground state of a gapped translationally-invariant system on a quantum computer is presented, which we call Scalable Circuits ADAPT-VQE (SC-ADAPT-VQE). This algorithm uses the exponential decay of correlations between distant regions of the ground state, together with ADAPT-VQE, to construct quantum circuits for state preparation that can be scaled to arbitrarily large systems. These scalable circuits can be determined using classical computers, avoiding the challenging task of optimizing parameterized circuits on a quantum computer. SC-ADAPT-VQE is applied to the Schwinger model, and shown to be systematically improvable, with an accuracy that converges exponentially with circuit depth. Both the structure of the circuits and the deviations of prepared wavefunctions are found to become independent of the number of spatial sites, $L$ . This allows for a controlled extrapolation of the circuits, determined using small or modest-sized systems, to arbitrarily large $L$ . The circuits for the Schwinger model are determined on lattices up to $L = 14$ (28 qubits) with the qiskit classical simulator, and subsequently scaled up to prepare the $L = 50$ (100 qubits) vacuum on IBM's 127 superconducting-qubit quantum computers ibm_brisbane and ibm_cusco. After introducing an improved error-mitigation technique, which we call Operator Decoherence Renormalization, the chiral condensate and charge-charge correlators obtained from the quantum computers are found to be in good agreement with classical Matrix Product State simulations.
Comments:
15 pages + appendices. 17 figures, 13 tables
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2308.04481 [pdf]
PRX Quantum(2024)·269 citations
05
[Submitted on 8 Aug 2023] (cross-list from hep-th)
Hydrodynamic and Non-hydrodynamic Excitations in Kinetic Theory -- A Numerical Analysis in Scalar Field Theory
Stephan Ochsenfeld🇩🇪 · Sören Schlichting🇩🇪
Viscous hydrodynamics serves as a successful mesoscopic description of the Quark-Gluon Plasma produced in relativistic heavy-ion collisions. In order to investigate, how such an effective description emerges from the underlying microscopic dynamics we calculate the hydrodynamic and non-hydrodynamic modes of linear response in the sound channel from a first-principle calculation in kinetic theory. We do this with a new approach wherein we discretize the collision kernel to directly calculate eigenvalues and eigenmodes of the evolution operator. This allows us to study the Green's functions at any point in the complex frequency space. Our study focuses on scalar theory with quartic interaction and we find that the analytic structure of Green's functions in the complex plane is far more complicated than just poles or cuts which is a first step towards an equivalent study in QCD kinetic theory.
Comments:
30 pages and 8 figures. v2 changes: Added a more nuanced discussion about hydrodynamization in introduction. Clarified the potential differences between the QFT scalar \phi^4 theory and kinetic theory derived from it. Added some additional discussion of a hydrodynamic breakdown scale k_c to the conclusion of the paper. Fixed some typos. v3 changes: added code to source files
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2308.04491 [pdf]
JHEP(2023)·28 citations
06
[Submitted on 9 Aug 2023] (cross-list from hep-ph)
Gravitational form factors of the proton from near-threshold vector meson photoproduction
Xiao-Yun Wang🇨🇳 · Fancong Zeng🇨🇳 · Jiyuan Zhang🇨🇳
We embark on a systematical analysis of the quark and gluon gravitational form factors (GFFs) of the proton, by connecting energy-momentum tensor (EMT) and the near-threshold vector meson photoproduction (NTVMP). Concretely, the quark contributions of GFFs are determined by global fitting the cross section of the lightest vector meson $ρ^{0}$ photoproduction. Combined with the gluon GFFs achieved from heavy quarkonium $J / ψ$ photoproduction data, the complete GFFs are obtained and compared with the experimental results and Lattice QCD determinations. In addition, we use the Resonances Via Padé (RVP) method based on the Schlessinger Point Method (SPM) to obtain a model-independent quark $D$ -term distribution by direct analytical continuation of Deep Virtual Compton Scattering (DVCS) experimental data. If errors are considered, the results obtained by RVP are basically consistent with those obtained by NTVMP. Moreover, the comprehensive information on GFFs helps us to uncover the mass distribution and mechanical properties inside the proton. This work is not only an important basis for delving the proton enigmatic properties, unraveling the secrets of the proton internal nature but also have significance theoretical guiding for future JLab and EICs experimental measurements.
Comments:
9 pages,8 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2308.04644 [pdf]
CPC(2024)·14 citations
07
[Submitted on 9 Aug 2023] (cross-list from cond-mat.quant-gas)
Cooper pairing and tripling in one-dimensional spinless fermions with attractive two- and three-body forces
Yixin Guo · Hiroyuki Tajima
We theoretically investigate in-medium three-body correlations in one-dimensional spinless fermions with antisymmetrized two- and three-body attractive interactions. By investigating the variational problem of three-body states above the Fermi sea, we illuminate the fate of the in-medium three-body cluster states both in the special case with pure attractive three-body interaction as well as in the case with the coexistence of two- and three-body interactions. Our results testify that the fermion-dimer repulsion is canceled by including the three-body interactions, and stable three-body clusters can be formed. We further feature a phase diagram consisting of the $p$ -wave Cooper pairing and Cooper tripling phases in a plane of $p$ -wave two- and three-body coupling strengths.
Comments:
11 pages, 5 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el); Superconductivity (cond-mat.supr-con); Nuclear Theory (nucl-th)
arXiv:
2308.04737 [pdf]
PRA(2023)·3 citations
08
[Submitted on 9 Aug 2023] (cross-list from cond-mat.quant-gas)
Medium-induced bosonic clusters in a Bose-Fermi mixture: Towards simulating cluster formations in neutron-rich matter
Yixin Guo · Hiroyuki Tajima
Considering bosonic atoms immersed in a dilute Fermi gas, we theoretically investigate medium-induced bosonic clusters associated with fermion-mediated two- and three-body interactions. Using the variational approach combined with the fermion-mediated interactions, we numerically calculate the binding energies of two- and three-body bosonic clusters in a one-dimensional system. It is found that the bosonic clusters can be formed even with a repulsive boson-boson interaction due to the fermion-mediated interactions. Our results would be relevant for ultracold atomic systems as well as analogue quantum simulations of alpha clusters in neutron-rich matter.
Comments:
11 pages, 9 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el); Superconductivity (cond-mat.supr-con); Nuclear Theory (nucl-th)
arXiv:
2308.04738 [pdf]
PRA(2024)·7 citations
09
[Submitted on 9 Aug 2023] (cross-list from hep-ph)
Meson cloud contributions to the Dalitz decays of decuplet to octet baryons
G. Ramalho🇰🇷 · K. Tsushima🇧🇷
We study the role of the meson cloud on the electromagnetic transitions from decuplet ( $B^{'}$ ) to octet ( $B$ ) baryons in terms of the squared four-momentum transfer $q^{2}$ . In the quark model framework, the meson cloud dressing of the quark cores gives important contributions to the $γ^{*} N \to Δ (1232)$ transition form factors. In the present work, we estimate the meson cloud contributions of all decuplet to octet baryon transitions ( $γ^{*} B \to B^{'}$ or $B^{'} \to γ^{*} B$ ). Models that combine valence quark effects with pion and kaon cloud dressing provide a fair description of the radiative decays of decuplet to octet baryons, namely the $Σ^{0} (1385) \to γ Λ (1116)$ and $Σ^{+} (1385) \to γ Σ^{+} (1193)$ decays. Previous studies indicated the relevance of the pion cloud effects on the $B^{'} \to γ^{*} B$ transition, but also suggested that the kaon cloud contributions may be important in the timelike region. We combine then the contributions of the bare core, estimated by a covariant quark model, with $q^{2}$ -dependent contributions of pion and kaon clouds. We use the framework to calculate the Dalitz decay rates and the Dalitz decay widths of decuplet baryons in octet baryons with di-electrons ( $B^{'} \to e^{+} e^{-} B$ ) or di-muons ( $B^{'} \to μ^{+} μ^{-} B$ ). We conclude, based on the magnitude of our results, that most estimates of the $B^{'} \to e^{+} e^{-} B$ Dalitz decay widths may be tested at HADES and PANDA (GSI) in a near future. We discuss also the possibility of measuring the $Δ (1232) \to μ^{+} μ^{-} N$ and $Σ^{0} (1385) \to μ^{+} μ^{-} Λ (1116)$ decay widths in some facilities, based on the estimated branching ratios.
Comments:
Published at Phys. Rev. D. 28 pages, 8 figures, 11 tables. More compacted version. Appendix removed. Updated bibliography
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2308.04773 [pdf]
PRD(2023)·9 citations
10
[Submitted on 9 Aug 2023] (cross-list from nucl-ex)
STAR Experimental Highlights at Hard Probes 2023
Nihar Ranjan Sahoo (for the STAR Collaboration)🇮🇳
We highlight the STAR experiment's hard probes results, including jets and heavy flavor production in heavy-ion collisions to study the properties of the quark-gluon plasma. Various jet-substructure observables in proton-proton collisions are presented to explore both perturbative and non-perturbative regimes of quantum chromodynamics. Finally, we discuss the STAR experiment's hard probes physics program for ongoing data taking.
Comments:
Hard Probes 2023 Conference, Aschaffenburg, Germany, STAR highlights plenary talk on hard probes, 10 pages, 9 figures
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2308.04801 [pdf]
PoS(2024)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE