Nuclear Theory·nucl-th

Thursday·February 16, 2023

17 papers—10 primary·7 cross-listed

01
[Submitted on 14 Feb 2023]
Second-Order Perturbation Theory in Continuum Quantum Monte Carlo Calculations
Ryan Curry · Joel E. Lynn · Kevin E. Schmidt · Alexandros Gezerlis
We report on the first results for the second-order perturbation theory correction to the ground-state energy of a nuclear many-body system in a continuum quantum Monte Carlo calculation. Second-order (and higher) perturbative corrections are notoriously difficult to compute in most ab initio many-body methods, where the focus is usually on obtaining the ground-state energy. By mapping our calculation of the second-order energy correction to an evolution in imaginary time using the diffusion Monte Carlo method, we are able to calculate these nuclear corrections for the first time. After benchmarking our method in the few-body sector, we explore the effect of charge-independence-breaking terms in the nuclear Hamiltonian. We then employ that approach to investigate the many-body, perturbative, order-by-order convergence that is fundamental in modern theories of the nucleon-nucleon interaction derived from chiral effective field theory. We find cutoff-dependent perturbativeness between potentials at higher chiral order and also that the difference between leading order and next-to-leading order potentials is nonperturbative; both of these results have important implications for future nuclear many-body calculations. Our approach is quite general and promises to be of wide applicability.
Comments:
6 pages, 3 figures, 1 table
Subjects:
Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); Computational Physics (physics.comp-ph)
arXiv:
2302.07285 [pdf]
PRResearch(2023)·15 citations
02
[Submitted on 14 Feb 2023]
Differential charge radii: self-consistency and proton-neutron interaction effects
U. C. Perera · A. V. Afanasjev
The analysis of self-consistency and proton-neutron interaction effects in the buildup of differential charge radii has been carried out in covariant density functional theoretical calculations without pairing interaction. Two configurations of the $^{218}$ Pb nucleus, generated by the occupation of the neutron $1 i_{11/2}$ and $2 g_{9/2}$ subshells, are compared with the ground state configuration in $^{208}$ Pb. The interaction of added neutron(s) and the protons forming the $Z = 82$ proton core is responsible for a major contribution to the buildup of differential charge radii. It depends on the overlaps of proton and neutron wave functions and leads to a redistribution of single-particle density of occupied proton states which in turn modifies the charge radii. Self-consistency effects affecting the shape of proton potential, total proton densities and the energies of the single-particle proton states provide only secondary contribution to differential charge radii. The buildup of differential charge radii is a combination of single-particle and collective phenomena. The former is due to proton-neutron interaction, the impact of which is state dependent, and the latter reflects the fact that all occupied proton single-particle states contribute to this process. The neglect of either one of these aspects of the process by ignoring proton-neutron interaction and self-consistency effects as it is done in macroscopic+microscopic approach or by introducing the core as in spherical shell model introduces uncontrollable errors and restricts the applicability of such approaches to the description of differential charge radii.
Comments:
14 pages, 8 figures, submitted to Physical Review C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2302.07295 [pdf]
PRC(2023)·13 citations
03
[Submitted on 15 Feb 2023]
Shape and multiple shape coexistence of nuclei within covariant density functional theory
Y. L. Yang · P. W. Zhao · Z. P. Li
Shape and multiple shape coexistence of nuclei are investigated throughout the nuclear chart by calculating the low-lying spectra and the quadrupole shape invariants for even-even nuclei with $10 \leq Z \leq 104$ from the proton drip line to the neutron one within a five-dimensional collective Hamiltonian based on the covariant density functional PC-PK1. The quadrupole shape invariants are implemented to characterize the quadrupole deformations of low-lying $0^{+}$ states and predict nuclear mass regions of shape and multiple shape coexistence. The predicted low-lying spectra and the shape or multi-shape coexisting nuclei are overall in good agreement with the available experimental results. In addition, the present work predicts a wealth of nuclei with shape or multiple shape coexistence in the neutron-rich regions. The connection between the strong $E 0$ transition strength and the occurrence of shape coexistence is analyzed systemically. It is found that nuclei with pronounced shape coexistence generally have strong $E 0$ transition strengths, while the reverse may not be true. The present results can serve as useful guidelines for experimental searches and theoretical studies of shape and multiple shape coexistence, especially in neutron-rich regions.
Comments:
8 pages, 8 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2302.07417 [pdf]
PRC(2023)·24 citations
04
[Submitted on 15 Feb 2023]
Systematic shell-model study of $^{98 - 130}$ Cd isotopes and $8^{+}$ isomeric states
Deepak Patel · Praveen C. Srivastava · Noritaka Shimizu
We present systematic shell-model studies of even-even $^{98 - 130}$ Cd isotopes using a realistic effective shell-model interaction derived from the G-matrix approach with an inert core $^{88}$ Sr. Our calculated low-lying excited energy spectra and electromagnetic properties are compared with the experimental data. On the basis of recently available experimental data, we predict spins and parities corresponding to unconfirmed states. We also discuss the properties of $8^{+}$ isomeric states in $^{98 - 104, 130}$ Cd isotopes.
Comments:
20 pages, 13 figures,
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2302.07514 [pdf]
NPA(2023)·4 citations
05
[Submitted on 15 Feb 2023]
Preequilibrium cluster emission in massive transfer reactions near Coulomb barrier energy
Zhao-Qing Feng
Within the framework of the dinuclear system model, the preequilibrium emission of neutron, proton, deuteron, triton, $^{3}$ He, $α$ , $^{6}$ Li, $^{7}$ Li, $^{8}$ Be and $^{9}$ Be in the transfer reactions of $^{12}$ C + $^{209}$ Bi, $^{40, 48}$ Ca+ $^{238}$ U, $^{238}$ U+ $^{238}$ U and $^{238}$ U+ $^{248}$ Cm has been systematically investigated. The production rate, kinetic energy spectra and emission angular distribution are calculated. It is found that the preequilibrium emission mechanism is associated with the reaction system and beam energy. The preequilibrium cross sections of proton, deuteron, triton and alpha are comparable in magnitude. The reaction with $^{40}$ Ca is favorable for the cluster emission in comparison with $^{48}$ Ca on $^{238}$ U at the near barrier energy. A broad angular distribution of the preequilibrium cluster is found in the heavy systems $^{238}$ U+ $^{238}$ U and $^{238}$ U+ $^{248}$ Cm.
Comments:
9 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2302.07544 [pdf]
PRC(2023)·2 citations
06
[Submitted on 15 Feb 2023]
Production of Strange and Charm Hadrons in Pb+Pb Collisions at $s_{N N} =$ 5.02 TeV
Wen-bin Chang🇨🇳 · Rui-qin Wang🇨🇳 · Jun Song🇨🇳 · Feng-lan Shao🇨🇳 · Qun Wang🇨🇳 · Zuo-tang Liang🇨🇳
Using a quark combination model with the equal-velocity combination approximation, we study the production of hadrons with strangeness and charm flavor quantum numbers in Pb+Pb collisions at $s_{N N} =$ 5.02 TeV. We present analytical expressions and numerical results for these hadrons' transverse momentum spectra and yield ratios. Our numerical results agree well with the experimental data available. The features of strange and charm hadron production in the quark--gluon plasma at the early stage of heavy ion collisions are also discussed.
Comments:
12 pages, 9 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2302.07546 [pdf]
Symmetry(2023)·3 citations
07
[Submitted on 15 Feb 2023]
Hidden Euclidean dynamical symmetry in the U(n+1) vibron model
Yu Zhang · Zi-Tong Wang · Hong-Di Jiang · Xin Chen
Based on the boson realization of the Euclidean algebras, it is found that the E( $n$ ) dynamical symmetry (DS) may emerge at the critical point of the U( $n$ )-SO( $n + 1$ ) quantum phase transition. To justify this finding, we provide a detailed analysis of the critical dynamics in the U( $n + 1$ ) vibron model in both quantal and classical ways. It is further shown that the low-lying structure of $^{82}$ Kr may serve as an excellent empirical realization of the E(5) DS in experiments.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2302.07602 [pdf]
Symmetry(2022)·5 citations
08
[Submitted on 15 Feb 2023]
Quadrupole and octupole states in $^{152}$ Sm using the proton-neutron interacting boson model
Bao-Yue Hu · Yu Zhang · Gui-Xiu Na · Sheng-Nan Wang · Wei Teng
A scheme of solving the proton-neutron interacting boson model (IBM-2) in terms of the SU(3) basis is introduced, by which the IBM-2 coupled with an octupole boson is applied to describe the low-energy structure of the critical point nucleus, $^{152}$ Sm. The results indicate that the spectral properties of both the positive-parity bands and negative-parity bands in this nucleus can be well captured by the IBM-2 calculations through a simple Hamiltonian, thus providing an example of the IBM-2 in a unified description of quadrupole and octupole states in a transitional system. In addition, a statistical analysis of the low-spin states in the model is also provided.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2302.07610 [pdf]
J.Phys.G(2023)·2 citations
09
[Submitted on 15 Feb 2023]
The effect of weak magnetic photon emission from quark-gluon plasma
Jing-An Sun🇨🇳 · Li Yan🇨🇳
We propose a novel effect that accounts for the photon emission from a quark-gluon plasma in the presence of a weak external magnetic field. Although the weak magnetic photon emission from quark-gluon plasma only leads to a small correction to the photon production rate, the induced photon spectrum can be highly azimuthally anisotropic, as a consequence of the coupled effect of the magnetic field and the longitudinal dynamics in the background medium. With respect to a realistic medium evolution containing a tilted fireball configuration, the direct photon elliptic flow from experiments is reproduced. In comparison to the experimental data of direct photon elliptic flow, in heavy-ion collisions the magnitude of the magnetic field before 1 fm/c can be extracted. For the top energy of RHIC collisions, right after the pre-equilibrium evolution, $∣ e B ∣$ is found no larger than a few percent of the pion mass square.
Comments:
revised version with a new appendix in the supplemental material. code used to calculate photon yields and elliptic flow uploaded
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2302.07696 [pdf]
PLB(2024)·16 citations
10
[Submitted on 13 Feb 2023]
Generation, dynamics, and correlations of the fission fragments' angular momenta
Guillaume Scamps · George Bertsch
The generation of angular momentum in fissioning nuclei is not well understood. The predictions of different models disagree, particularly concerning the correlation between the fragments' angular momenta. In this article, a time-dependent collective Hamiltonian model is proposed to treat the generation of the angular momentum in the fission fragments due to the quantum uncertainty principle as well as the dynamics of the collective wave function during and after scission. The model is constructed in the framework of the frozen Hartree-Fock approximation using a Skyrme energy functional to extract deformations of the fission fragments as well as the interactions in a derived collective Hamiltonian. The fission reactions studied are $^{240}$ Pu $\to$ $^{132}$ Sn+ $^{108}$ Ru and $^{240}$ Pu $\to$ $^{144}$ Ba+ $^{96}$ Sr. The model can account for a large part of the angular momentum found in experimental data. The orientation of the angular momentum of each fragment is found to be mainly in the plane perpendicular to the fission axis, in agreement with the experiment. The magnitudes of the angular momenta in the two fragments are nearly uncorrelated, in agreement with the recent experimental data of Wilson et al., Nature (London) 590, 566 (2021). Some of the conclusions of the traditional collective vibration model are supported by the present model but some are not. Surprisingly, it is found that the angular momenta of the fragments are slightly correlated positively as in a wriggling mode. It is also found that the presence of an octupole deformation in a fragment can significantly increase the generated angular momentum.
Comments:
14 pages, 15 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2302.07792 [pdf]
PRC(2023)·16 citations
11
[Submitted on 14 Feb 2023] (cross-list from hep-ph)
Generalized parton distributions through universal moment parameterization: non-zero skewness case
Yuxun Guo🇺🇸 · Xiangdong Ji🇺🇸 · M. Gabriel Santiago🇺🇸 · Kyle Shiells🇨🇦 · Jinghong Yang🇺🇸
We present the first global analysis of generalized parton distributions (GPDs) combing lattice quantum chromodynamics (QCD) calculations and experiment measurements including global parton distribution functions (PDFs), form factors (FFs) and deeply virtual Compton scattering (DVCS) measurements. Following the previous work where we parameterize GPDs in terms of their moments, we extend the framework to allow for the global analysis at non-zero skewness. Together with the constraints at zero skewness, we fit GPDs to global DVCS measurements from both the recent JLab and the earlier Hadron-Electron Ring Accelerator (HERA) experiments with two active quark flavors and leading order QCD evolution. With certain choices of empirical constraints, both sea and valence quark distributions are extracted with the combined inputs, and we present the quark distributions in the proton correspondingly. We also discuss how to extend the framework to accommodate more off-forward constraints beyond the small $ξ$ expansion, especially the lattice calculated GPDs.
Comments:
23 pages, 7 figures and 3 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2302.07279 [pdf]
JHEP(2023)·61 citations
12
[Submitted on 14 Feb 2023] (cross-list from hep-ph)
Empirical Determination of the Pion Mass Distribution
Yin-Zhen Xu🇪🇸 · Khépani Raya🇪🇸 · Zhu-Fang Cui🇨🇳 · Craig D. Roberts🇨🇳 · J. Rodríguez-Quintero🇪🇸
Existing pion+nucleus Drell-Yan and electron+pion scattering data are used to develop ensembles of model-independent representations of the pion generalised parton distribution (GPD). Therewith, one arrives at a data-driven prediction for the pion mass distribution form factor, $θ_{2}$ . Compared with the pion elastic electromagnetic form factor, $θ_{2}$ is harder: the ratio of the radii derived from these two form factors is $r_{π}^{θ_{2}} / r_{π} = 0.79 (3)$ . Our data-driven predictions for the pion GPD, related form factors and distributions should serve as valuable constraints on theories of pion structure.
Comments:
9 pages, 6 figures, 1 table. Version accepted for publication as an Express Letter in Chin. Phys. Lett
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:
2302.07361 [pdf]
Chin.Phys.Lett.(2023)·24 citations
13
[Submitted on 14 Feb 2023] (cross-list from hep-ph)
Prospects for ditauonium discovery at colliders
David d'Enterria🇨🇭 · Hua-Sheng Shao🇫🇷
The feasibility of observing ditauonium, the bound state of two tau leptons, at $e^{+} e^{-}$ colliders (BES III at $s = 3.78$ GeV, Belle II at $s = 10.6$ GeV, a future super tau-charm factory (STCF) at $s \approx 2 m_{τ}$ , and the FCC-ee at $s = 91.2$ GeV) as well as in hadronic and photon-photon collisions at the LHC, is studied. Cross sections and expected yields for spin-0 para- ( $T_{0}$ ) and spin-1 ortho- ( $T_{1}$ ) ditauonium are presented for nine different production and decay processes. Para-ditauonium can be observed at the FCC-ee via photon fusion in its diphoton decay ( $γ γ \to T_{0} \to γ γ$ ). Ortho-ditauonium can be observed at STCF via $e^{+} e^{-} \to T_{1} \to μ^{+} μ^{-}$ , where a threshold scan with monochromatized beams can also provide a very precise extraction of the tau lepton mass with a $O (25$ keV) uncertainty or less. Observing pp $\to T_{1} (μ^{+} μ^{-}) + X$ at the LHC is possible by identifying its displaced vertex with a good control of the combinatorial dimuon background. In addition, we compute the rare decay branching fractions of ditauonium into quarkonium plus a photon.
Comments:
15 pages, 6 figures. Minor mods. to match published version: Phys. Lett. B 842 (2023) 137960
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2302.07365 [pdf]
PLB(2023)·32 citations
14
[Submitted on 14 Feb 2023] (cross-list from nucl-ex)
First Evidence of Axial Shape Asymmetry and Configuration Coexistence in $^{74}$ Zn: Suggestion for a Northern Extension of the $N = 40$ Island of Inversion
M. Rocchini🇨🇦 · P. E. Garrett🇨🇦 · M. Zielinska🇫🇷 · S. M. Lenzi🇮🇹 · D. D. Dao🇫🇷 · F. Nowacki🇫🇷 · V. Bildstein🇨🇦 · A. D. MacLean🇨🇦 · B. Olaizola🇨🇦 · Z. T. Ahmed🇨🇦 · C. Andreoiu🇨🇦 · A. Babu🇨🇦 and 32 other authors
The excited states of $N = 44$ $^{74}$ Zn were investigated via $γ$ -ray spectroscopy following $^{74}$ Cu $β$ decay. By exploiting $γ$ - $γ$ angular correlation analysis, the $2_{2}^{+}$ , $3_{1}^{+}$ , $0_{2}^{+}$ and $2_{3}^{+}$ states in $^{74}$ Zn were firmly established. The $γ$ -ray branching and $E 2/ M 1$ mixing ratios for transitions de-exciting the $2_{2}^{+}$ , $3_{1}^{+}$ and $2_{3}^{+}$ states were measured, allowing for the extraction of relative $B (E 2)$ values. In particular, the $2_{3}^{+} \to 0_{2}^{+}$ and $2_{3}^{+} \to 4_{1}^{+}$ transitions were observed for the first time. The results show excellent agreement with new microscopic large-scale shell-model calculations, and are discussed in terms of underlying shapes, as well as the role of neutron excitations across the $N = 40$ gap. Enhanced axial shape asymmetry (triaxiality) is suggested to characterize $^{74}$ Zn in its ground state. Furthermore, an excited $K = 0$ band with a significantly larger softness in its shape is identified. A shore of the $N = 40$ ``island of inversion'' appears to manifest above $Z = 26$ , previously thought as its northern limit in the chart of the nuclides.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2302.07394 [pdf]
PRL(2023)·17 citations
15
[Submitted on 15 Feb 2023] (cross-list from hep-ph)
Parton Decomposition of Nucleon Spin and Momentum: Gluons from Dressed Quarks
Peter C. Tandy🇺🇸
The lowest two Mellin moments of hadronic Generalized Parton Distributions are explored within a model that allows investigation of the inter-related quark and gluon contributions. For light quarks their dynamical connection is strong due to quark dressing. Our principal focus is the angular momentum $J$ of the nucleon. This work employs and extends dynamical insights obtained from our recent model results for quark and gluon momentum fractions $⟨ x ⟩_{q/g}$ in both pion and nucleon. The employed model is based on the Rainbow-Ladder truncation of the Dyson-Schwinger equations of QCD. The special case of a 1-loop treatment of a single hadronic quark is used to motivate several insights and obtain initial estimates such as the Wilson line correction to the established Landau gauge model ( $- 7%$ for both $J_{q}$ and $⟨ x ⟩_{q}$ ), and the "binding gluon" contribution to $⟨ x ⟩_{g}$ ( $\leq 10%$ ). We obtain the proton $J$ within 1\% after inclusion of the pion cloud mechanism to produce the sea. The gluon second Mellin moments of the proton reflect similar dynamics; ( $⟨ x ⟩_{g}$ , $J_{g}$ ) are (26\% , 24\%) at model scale, and (40\%, 38\%) at $2$ GeV. We also find that $J_{tot}$ is shared almost equally between the total orbital and total intrinsic spin contributions.
Comments:
8 pages, 5 figures. Submitted for publication. This version clarifies and qualifies the approach and methods, and corrects typing errors
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2302.07473 [pdf]
PLB(2023)·5 citations
16
[Submitted on 15 Feb 2023] (cross-list from nucl-ex)
Electric dipole polarizability of $^{40}$ Ca
R. W. Fearick (1) · P. von Neumann-Cosel (2) · S. Bacca (3,4) · J. Birkhan (2) · F. Bonaiti (3) · I. Brandherm (2) · G. Hagen (5,6) · H. Matsubara (7,8) · W. Nazarewicz (9) · N. Pietralla (2) · V. Yu. Ponomarev (2) · P. -G. Reinhard (10) and 5 other authors
The electric dipole strength distribution in $^{40}$ Ca between 5 and 25 MeV has been determined at RCNP, Osaka, from proton inelastic scattering experiments at very forward angles. Combined with total photoabsorption data at higher excitation energy, this enables an extraction of the electric dipole polarizability $α_{D}$ ( $^{40}$ Ca) = 1.92(17) fm $^{3}$ . Together with the measured $α_{D}$ in $^{48}$ Ca, it provides a stringent test of modern theoretical approaches, including coupled cluster calculations with chiral effective field theory interactions and state-of-the art energy density functionals. The emerging picture is that for this medium-mass region dipole polarizabilities are well described theoretically, with important constraints for the neutron skin in $^{48}$ Ca and related equation of state quantities.
Comments:
6 pages, 3 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2302.07490 [pdf]
PRResearch(2023)·26 citations
17
[Submitted on 15 Feb 2023] (cross-list from hep-ph)
Impact of vorticity and viscosity on the hydrodynamic evolution of hot QCD medium
Bhagyarathi Sahoo🇮🇳 · Captain R. Singh🇮🇳 · Dushmanta Sahu🇮🇳 · Raghunath Sahoo🇮🇳 · Jan-e Alam🇮🇳
The strongly interacting transient state of quark-gluon plasma (QGP) medium created in ultra-relativistic collisions survives for a duration of a few fm/c. The spacetime evolution of QGP crucially depends on the equation of state (EoS), vorticity, viscosity, and external magnetic field. In the present study, we obtain the lifetime of a vortical QGP fluid within the ambit of relativistic second-order viscous hydrodynamics. We observe that the coupling of vorticity and viscosity significantly increases the lifetime of vortical QGP. The inclusion of a static magnetic field, vorticity, and viscosity makes the evolution slower. However, the static magnetic field slightly decreases the QGP lifetime by accelerating the evolution process for a non-rotating medium. We also report the rate of change of vorticity in the QGP, which will be helpful in studying the behavior of the medium in detail.
Comments:
Same as the EPJC published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2302.07668 [pdf]
EPJC(2023)·23 citations

Affiliations

first authorsco-authorsvia INSPIRE