Nuclear Theory·nucl-th

Monday·April 15, 2024

7 papers—7 primary·0 cross-listed

01
[Submitted on 12 Apr 2024]
Spherical-like spectra for the description of the normal states of $^{108 - 120}$ Cd in the SU3-IBM and the $Q_{2_{1}^{+}}$ anomaly
Tao Wang · Xin Chen · Yu Zhang
The Cd puzzle implies that the phonon excitation of a spherical nucleus should be questioned and refuted. For understanding this spherical-like $γ$ -soft mode newly found experimentally, a possible answer was proposed recently in the SU3-IBM. In this paper, the evolutions of the normal states in $^{108 - 120}$ Cd are investigated and compared with the experimental results. For better explaining the nearly zero B(E2) values between the $0_{2}^{+}$ state and the $2_{1}^{+}$ state, except for the SU(3) second-order and third-order Casimir operators, other SU(3) higher-order interactions are also considered in detail. It can be found that the results of theoretical fitting and experimental data agree well with simple parameter selection. The spherical-like spectra really exist. The deficiency may come from the lack of configuration mixing. The realistic spectra characteristics of the spherical-like spectra are found for $^{118, 120}$ Cd and the electric quadrupole moments of the $2_{1}^{+}$ state are predicted. The $Q_{2_{1}^{+}}$ anomaly in $^{108 - 116}$ Cd are also discussed.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2404.08198 [pdf]
CPC(2025)·13 citations
02
[Submitted on 12 Apr 2024]
The evolution equation for the energy-momentum moments of the non-equilibrium density function & The regularized relativistic third order hydrodynamics
Dasen Ye🇨🇦 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦
In this work, we first derive the evolution equation for the general energy-momentum moment of $δ f$ , where $δ f$ is the deviation from the local equilibrium phase space density. We then introduce a relativistic extension of regularized hydrodynamics developed in the non-relativistic case by Struchtrup and Torrilhon that combines the method of moments and Chapman-Enskog expansion. Hydrodynamic equations up to the third-order in gradients are then systematially derived within the context of a single species system and the relaxation time approximation. This is followed by a series of linear stability and causality analysis. For the system of massless particles without any charge conservation, the third-order hydrodynamics is shown to be linearly stable and causal.
Comments:
37 pages with extensive appendices. 8 figures. Version accepted by Physical Review C
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2404.08204 [pdf]
PRC(2024)·5 citations
03
[Submitted on 12 Apr 2024]
High-fidelity Nuclear Coherent Population Transfer via the Mixed-State Inverse Engineering
Ying Wang · Fu-Quan Dou
Nuclear coherent population transfer (NCPT) plays an important role in the exploration and application of atomic nuclei. How to achieve high-fidelity NCPT remains so far challenging. Here, we investigate the complete population transfer of nuclear states. We first consider a cyclic three-level system, based on the mixed-state inverse engineering scheme by adding additional laser fields in an open three-level nuclear system with spontaneous emission. We find the amplitude of the additional field is related to the ratio of the pump and Stokes field amplitudes. As long as an appropriate additional field is selected, complete transfer can be achieved even when the intensities of the pump and Stokes fields are exceedingly low. The transfer efficiency exhibits excellent robustness with respect to laser peak intensity and pulse delay. We demonstrate the effectiveness through examples such as $^{229}$ Th, $^{223}$ Ra, $^{113}$ Cd, and $^{97}$ Tc, which have a long lifetime excited state, as well as $^{187}$ Re, $^{172}$ Yb, $^{168}$ Er and $^{154}$ Gd with a short lifetime excited state. Focusing on the case without additional coupling, we further reduce the three-level system to an effective two-level problem. We modify the pump and Stokes pulses by using counterdiabatic driving to implement high-fidelity population transfer. The schemes open up new possibilities for controlling nuclear states.
Comments:
9 pages,7 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2404.08384 [pdf]
PRC(2024)·3 citations
04
[Submitted on 12 Apr 2024]
$A b$ - $ini t i o$ nucleon-nucleon correlations and their impact on high energy $^{16}$ O+ $^{16}$ O collisions
Chunjian Zhang🇨🇳 · Jinhui Chen🇨🇳 · Giuliano Giacalone🇩🇪 · Shengli Huang🇺🇸 · Jiangyong Jia🇺🇸 · Yu-Gang Ma🇨🇳
Investigating nucleon-nucleon correlations inherent to the strong nuclear force is one of the core goals in nuclear physics research. We showcase the unique opportunities offered by collisions of $^{16}$ O nuclei at high-energy facilities to reveal detailed many-body properties of the nuclear ground state. We interface existing knowledge about the geometry of $^{16}$ O coming from \textit{ab-initio} calculations of nuclear structure with transport simulations of high-energy $^{16}$ O+ $^{16}$ O collisions. Bulk observables in these processes, such as the elliptic flow or the fluctuations of the mean transverse momentum, are found to depend significantly on the input nuclear model and to be sensitive to realistic clustering and short-range repulsive correlations, effectively opening a new avenue to probe these features experimentally. This finding demonstrates collisions of oxygen nuclei as a tool to elucidate initial conditions of small collision systems while fostering connections with effective field theories of nuclei rooted in quantum chromodynamics (QCD).
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2404.08385 [pdf]
PLB(2025)·52 citations
05
[Submitted on 12 Apr 2024]
Electromagnetic fields in low-energy heavy-ion collisions with baryon stopping
Ankit Kumar Panda🇮🇳 · Partha Bagchi🇮🇳 · Hiranmaya Mishra🇮🇳 · Victor Roy🇮🇳
We investigate the impact of baryon stopping on the temporal evolution of electromagnetic fields in vacuum at low-energy Au+Au collisions with $s_{N N} = 4$ - $20$ GeV. Baryon stopping is incorporated into the Monte-Carlo Glauber model by employing a parameterized velocity profile of participant nucleons with non-zero deceleration. The presence of these decelerating participants leads to noticeable changes in the centrality and $s_{N N}$ dependence of electromagnetic fields compared to scenarios with vanishing deceleration. The influence of baryon stopping differs for electric and magnetic fields, also exhibiting variations across their components. We observe slight alteration in the approximate linear dependency of field strengths with $s_{N N}$ in the presence of deceleration. Additionally, the longitudinal component of the electric field at late times becomes significant in the presence of baryon stopping.
Comments:
10 pages and 10 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2404.08431 [pdf]
PRC(2024)·12 citations
06
[Submitted on 12 Apr 2024]
Tensor factorization in ab initio many-body calculations: Triaxially-deformed (B) MBPT calculations in large bases
M. Frosini🇫🇷 · T. Duguet🇫🇷 · P. Tamagno🇫🇷
Whether for fundamental studies or nuclear data evaluations, first-principle calculations of atomic nuclei constitute the path forward. Today, performing \textit{ab initio} calculations (a) of heavy nuclei, (b) of doubly open-shell nuclei or (c) with a sub-percent accuracy is at the forefront of nuclear structure theory. While combining any two of these features constitutes a major challenge, addressing the three at the same time is currently impossible. From a numerical standpoint, these challenges relate to the necessity to handle (i) very large single bases and (ii) mode-6, \textit{i.e.} three-body, tensors (iii) that must be stored repeatedly. Performing second-order many-body perturbation theory(ies) calculations based on triaxially deformed and superfluid reference states of doubly open-shell nuclei up to mass $A = 72$ , the present work achieves a significant step forward by addressing challenge (i). To do so, the memory and computational cost associated with the handling of large tensors is scaled down via the use of tensor factorization techniques. The presently used factorization format is based on a randomized singular value decomposition that does not require the computation and storage of the very large initial tensor. The procedure delivers an inexpensive and controllable approximation to the original problem, as presently illustrated for calculations that could not be performed without tensor factorization. With the presently developed technology at hand, one can envision to perform calculations of yet heavier doubly open-shell nuclei at sub-percent accuracy in a foreseeable future.
Subjects:
Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph)
arXiv:
2404.08532 [pdf]
EPJA(2024)·14 citations
07
[Submitted on 12 Apr 2024]
Emulating generator coordinate method with extended eigenvector continuation: Lipkin-Meshkov-Glick model
Q. Y. Luo · X. Zhang · L. H. Chen · J. M. Yao
We present a benchmark study of generator coordinate method (GCM) combined with eigenvector continuation (EC) in two different schemes for the low-lying states of Lipkin-Meshkov-Glick (LMG) model, where the interaction strength is treated as a controlling parameter, simulating quantum many-body systems with the phase transition from non-collective to collective states. We demonstrate that the EC $_{kmax}$ scheme accurately reproduces the low-lying states of the LMG model. In this scheme, the EC basis consists of the wave functions of low-lying states up to the $k_{max}$ -th state of sampling Hamiltonians. Compared to EC $_{1}$ , which only includes the wave functions of the $k$ -th state of sampling Hamiltonians for the $k$ -th state of a target Hamiltonian, the EC $_{kmax}$ scheme exhibits significantly improved efficiency and accuracy. This study suggests the potential utilization of the extended EC scheme as an efficient emulator for GCM calculations.
Comments:
9 pages with 12 figures
Subjects:
Nuclear Theory (nucl-th); Strongly Correlated Electrons (cond-mat.str-el)
arXiv:
2404.08581 [pdf]
PRC(2024)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE

Spherical-like spectra for the description of the normal states of 108−120Cd in the SU3-IBM and the Q21+​​ anomaly

The evolution equation for the energy-momentum moments of the non-equilibrium density function & The regularized relativistic third order hydrodynamics

High-fidelity Nuclear Coherent Population Transfer via the Mixed-State Inverse Engineering

Ab-initio nucleon-nucleon correlations and their impact on high energy 16O+16O collisions

Electromagnetic fields in low-energy heavy-ion collisions with baryon stopping

Tensor factorization in ab initio many-body calculations: Triaxially-deformed (B) MBPT calculations in large bases

Emulating generator coordinate method with extended eigenvector continuation: Lipkin-Meshkov-Glick model

Affiliations

Spherical-like spectra for the description of the normal states of $^{108 - 120}$ Cd in the SU3-IBM and the $Q_{2_{1}^{+}}$ anomaly

$A b$ - $ini t i o$ nucleon-nucleon correlations and their impact on high energy $^{16}$ O+ $^{16}$ O collisions