Article
Physics, Multidisciplinary
Bing-Nan Lu, Ning Li, Serdar Elhatisari, Yuan-Zhuo Ma, Dean Lee, Ulf-G Meissner
Summary: We present a new method for computing perturbative corrections in projection QMC calculations and demonstrate it by computing nuclear ground state energies for a realistic chiral interaction. In contrast to the natural ordering, we find remarkably large second-order energy corrections.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Particles & Fields
Fedor K. Popov, Yifan Wang
Summary: The study focuses on the dynamics of defects in the Klebanov-Tarnopolsky tensor model, identifying a new large N limit in the presence of defects and proving that the defect one-point function only receives contributions from melonic trees. By solving a closed Schwinger-Dyson equation, the defect one-point function is determined non-perturbatively, leading to the description of nontrivial conformal defects at large distances. Additionally, analysis of the defect two-point function and its decomposition using the operator-product-expansion provides explicit formulae for one-point functions of bilinear operators and the stress-energy tensor.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Astronomy & Astrophysics
Tim Neidig, Kai Gallmeister, Carsten Greiner, Marcus Bleicher, Volodymyr Vovchenko
Summary: The study reveals that the abundances of light clusters remain constant from chemical freeze-out to kinetic freeze-out in heavy ion collisions, due in part to the partial chemical equilibrium of stable hadrons.
Article
Physics, Multidisciplinary
Wouter Ryssens, Giuliano Giacalone, Bjoern Schenke, Chun Shen
Summary: State-of-the-art hydrodynamic simulations cannot reproduce the observed elliptic flow of particles at RHIC due to inappropriate treatment of nuclear deformations in the modeling of quark-gluon plasma initial conditions. Past studies neglected the relationship between hexadecapole deformation and surface quadrupole moment deformation. Correcting for this effect restores agreement with RHIC data.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
Gabriel S. Rocha, Gabriel S. Denicol, Jorge Noronha
Summary: This study discusses perturbative expansions and the calculation of transport coefficients in relativistic hydrodynamics, exploring the impact of different out-of-equilibrium definitions on the development of hydrodynamics. It introduces a method for deriving a new hydrodynamic formulation and compares the overall hydrodynamic evolution obtained with the Israel-Stewart equations and kinetic theory.
Article
Astronomy & Astrophysics
A. A. Zaitsev, D. A. Artemenkov, V. V. Glagolev, M. M. Chernyavsky, N. G. Peresadko, V. V. Rusakova, P. I. Zarubin
Summary: This paper investigates the peripheral dissociation of relativistic nuclei in nuclear track emulsion, focusing on the emerging ensembles of He and H nuclei, as well as the correlation between Be-8 nucleus formation and the multiplicity of accompanying alpha-particles. The study reveals an enhancement in the Be-8 contribution to dissociation with the alpha-particle multiplicity, and a consistent trend in the decays of B-9 nuclei and Hoyle states.
Article
Physics, Particles & Fields
Lukas Allwicher, Pere Arnan, Daniele Barducci, Marco Nardecchia
Summary: The study focuses on perturbative unitarity constraints on generic Yukawa interactions involving fields with arbitrary quantum numbers under Pi iSU(N-i) circle times U(1) group. Compact expressions for bounds on Yukawa couplings are derived based on how fields transform under different representations of SU(N) factors. The results are applied to specific models explaining anomalous measurements and it is shown that while the models can generally explain observed values, the required Yukawa couplings are pushed to the edge of the perturbative regime.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Xiaowen Li, Ze-Fang Jiang, Shanshan Cao, Jian Deng
Summary: Extremely large angular orbital momentum can induce a strong transverse polarization of partons in non-central heavy-ion collisions. We propose a perturbative approach to describe the formation and spacetime evolution of quark polarization in the quark-gluon plasma (QGP). By coupling the quark-potential scattering approach to realistic initial condition calculation and (3 + 1)-dimensional viscous hydrodynamic simulation, we find that different initial energy density distributions lead to different time evolution profiles of the longitudinal flow velocity gradient of the QGP, resulting in an approximately 15% difference in the final polarization of quarks.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Michal Szanecki, Andrzej Niedzwiecki, Andrzej A. Zdziarski
Summary: The study on the X-ray spectrum of the Seyfert galaxy NGC 4151 suggests that the narrow Fe K alpha line is produced in Compton-thin matter at a distance of several hundred gravitational radii, with a weak but significant relativistic reflection from a disk truncated at about 10 gravitational radii in bright X-ray states. Models with X-ray emission dominated by a source located very close to the black hole horizon are ruled out.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physics, Particles & Fields
Rajesh Kumar Gupta, Ramanpreet Singh
Summary: In this paper, we study the non-relativistic conformal field theory with a planar boundary in a flat space. We compute correlation functions of primary operators and derive the expression for the boundary conformal block. We also extend our discussion to the case of a general curved background with a boundary. As an example, we analyze the spectrum of boundary primary operators and calculate the scaling dimensions in a fermionic theory near one and three spatial dimensions.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Masaru Hongo, Koichi Hattori
Summary: This study presents a statistical mechanical derivation of relativistic magnetohydrodynamics based on (3 + 1)-dimensional quantum electrodynamics, showcasing the covariance of conservation laws and constitutive relations with respect to general coordinate transformations. By using the local Gibbs ensemble method and derivative expansion, exact constitutive relations are obtained for nonlinear relativistic magnetohydrodynamics. The results indicate the existence of electrical resistivities and viscosities, while satisfying Onsager's reciprocal relation and a set of inequalities consistent with the local second law of thermodynamics.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Multidisciplinary Sciences
Stefan Catheline
Summary: The starting point of this manuscript is classical rigid body rotation, which violates the principles of relativity due to infinite speed at infinite distance from the rotation center. To solve this problem, a phenomenological circle-based construction using Euclidean trigonometry is introduced: relativistic rigid body rotation. The physical Eulerian acceleration implied by this geometrical construction establishes links with Maxwell's equation and Lense-Thirring effect. Importantly, relativistic rigid body rotation is shown to be compatible with Lorentz transformation and provides new geometric interpretations of time and space intervals.
SCIENTIFIC REPORTS
(2023)
Article
Physics, Nuclear
K. E. Karakatsanis, K. Nomura
Summary: This paper investigates the spectroscopic properties that characterize the shape phase transitions in krypton isotopes with the mass A approximately 80. The results indicate that the nuclear structure evolves and exhibits a considerable degree of shape mixing as the neutron number changes. The transitional nucleus Kr-82 is identified as an empirical realization of the E(5) critical-point symmetry.
Article
Physics, Particles & Fields
Gustavo O. Heymans, Marcus Benghi Pinto
Summary: The optimized perturbation theory (OPT) shows promising results in resuming the perturbative series for the mass gap of the bidimensional phi (4) theory. It is able to generate reasonable non-perturbative results at NLO (one loop) and at order-g(7). Additionally, investigating the supercritical region reveals useful complimentary information that can be utilized for extrapolations to higher orders.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Chemistry, Physical
David Ferenc, Peter Jeszenszki, Edit Matyus
Summary: Variational and perturbative relativistic energies are calculated and compared for two-electron atoms and molecules with low nuclear charge numbers. It is found that the two approaches show good agreement, and the deviations can be attributed to higher-order relativistic corrections. The analysis reveals the importance of resummation provided by the variational procedure, particularly for intermediate nuclear charge numbers.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Lihan Guo, Xinhui Wu, Pengwei Zhao
Summary: The kernel ridge regression (KRR) and its updated version with odd-even effects (KRRoe) are used to improve mass predictions in relativistic density functional theory. Both techniques show significant improvements, particularly in predicting one-nucleon separation energies. The impact of KRRoe mass corrections on r-process simulations is studied, revealing its significant influence on nuclei in the light mass region, potentially affecting r-process abundances.
Article
Physics, Multidisciplinary
T. X. Huang, X. H. Wu, P. W. Zhao
Summary: This article presents the first application of machine-learning and kernel ridge regression (KRR) in studying neutron-capture reactions' cross-sections. The KRR approach effectively reduces the relative errors between experimental data and theoretical predictions, achieving high accuracy in cross-section determination.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2022)
Article
Astronomy & Astrophysics
X. H. Wu, Y. Y. Lu, P. W. Zhao
Summary: A multi-task learning framework, gradient kernel ridge regression, is developed for predicting nuclear masses and separation energies by introducing gradient kernel functions to the kernel ridge regression approach. The framework is trained using the WS4 mass model and improves the accuracy of theoretical predictions by considering the deviations between experimental and theoretical values. Significant improvements are achieved in both interpolation and extrapolation predictions for nuclear masses and separation energies.
Article
Astronomy & Astrophysics
Y. P. Wang, J. Meng
Summary: This study focuses on the microscopic understanding of the influence of pairing correlations or superfluidity on nuclear chiral rotation. By implementing a shell-model-like approach with exact particle number conservation based on the three-dimensional cranking covariant density functional theory, the pairing correlations are taken into account and applied to the chiral doublet bands in 135Nd. The results successfully reproduce the available data, including the I -omega relation and electromagnetic transition probabilities B(M1) and B(E2). It is found that superfluidity can reduce the critical frequency and facilitate chiral rotation by reducing particle/hole alignments along specific axes.
Article
Physics, Nuclear
J. Lin, Y. K. Wang, C. Xu, Z. H. Li, H. Hua, S. Q. Zhang, D. W. Luo, H. Y. Wu, J. Meng, X. G. Wu, Y. Zheng, C. B. Li, T. X. Li, Z. Y. Huang, H. Cheng, C. Y. Guo, Z. X. Zhou, Z. Q. Chen, C. G. Wang
Summary: The high-spin spectroscopy of Ni-61 has been investigated through the fusion-evaporation reaction Cr-54(B-11, 4n)Ni-61 at a beam energy of 54 MeV. One dipole band and one quadrupole band in Ni-61 have been identified for the first time, and they are considered as potential candidates for magnetic and antimagnetic rotational bands based on comparisons with Cd-110 and particle-plus-rotor model calculations. Microscopic tilted axis cranking covariant density functional theory has been used to further study these new bands, and good agreement between experiment and calculation has been achieved. The dipole band is characterized by the shears mechanism, while the quadrupole band is characterized by the two-shears-like mechanism. This study provides evidence for the possible coexistence of magnetic and antimagnetic rotations in the A approximate to 60 mass region.
Article
Multidisciplinary Sciences
Yakun Wang, Fangfang Xu, Tianxing Huang, Pengwei Zhao
Summary: The development of rare isotope beam facilities has expanded our knowledge of nuclear physics and solving the nuclear many-body problem is a crucial task. The relativistic density functional theory has been widely studied and applied in the description of nuclear properties. This paper provides an introduction to the theory and highlights its advantages in describing nuclear properties.
CHINESE SCIENCE BULLETIN-CHINESE
(2023)
Article
Physics, Nuclear
Y. L. Yang, P. W. Zhao
Summary: By combining the essential physics of nuclear wave functions and the strong expressive power of artificial neural networks, FeynmanNet has been developed as a deep-learning variational quantum Monte Carlo approach for predicting nuclear structure from first principles. It achieves very accurate solutions for ground-state energies and wave functions of helium-4, lithium-6, and oxygen-16, even considering the complex interactions between nucleons. Compared to conventional diffusion Monte Carlo approaches, FeynmanNet overcomes the fermion-sign problem and scales polynomially with nucleon numbers, making it a highly accurate and efficient method for ab initio nuclear structure prediction.
Article
Astronomy & Astrophysics
Qiang Zhao, Zhengxue Ren, Pengwei Zhao, Tae -Sun Park
Summary: The inclusion of nucleonic exchange energy has been a challenge for RDFT in nuclear physics. We propose an orbital-dependent relativistic Kohn-Sham density functional theory to incorporate the exchange energy with local Lorentz scalar and vector potentials. The obtained binding energies and charge radii for nuclei are benchmarked with the results of the traditional relativistic Hartree-Fock approach, demonstrating the accuracy and efficiency of the present framework.
Article
Physics, Nuclear
B. Li, D. Vretenar, Z. X. Ren, T. Niksic, J. Zhao, P. W. Zhao, J. Meng
Summary: The saddle-to-scission dynamics of induced fission process is investigated using a microscopic finite temperature model based on time-dependent nuclear density functional theory (TDDFT), which allows the tracking of local temperature evolution along the fission trajectories. By starting from a temperature corresponding to the experimental excitation energy of the compound system, nucleons are propagated along isentropic paths towards scission. The study focuses on the energy partitioning at scission, including dissipated energy along the fission path and the prescission kinetic energy, for four illustrative cases of induced fission. The model is also applied to the dynamics of neck formation and rupture, characterized by the formation of few-nucleon clusters in the low-density region between the nascent fragments.
Article
Physics, Nuclear
Y. L. Yang, P. W. Zhao, Z. P. Li
Summary: The study investigates the shape and multiple shape coexistence of nuclei by calculating low-lying spectra and quadrupole shape invariants. The results predict nuclear mass regions where shape and multiple shape coexistence occur and are in agreement with experimental data. The study also predicts the occurrence of shape or multiple shape coexistence in neutron-rich regions. The connection between strong E0 transition strength and shape coexistence is analyzed, indicating that nuclei with pronounced shape coexistence generally have strong E0 transition strengths.
Article
Physics, Nuclear
Sibo Wang, Hui Tong, Qiang Zhao, Chencan Wang, Peter Ring, Jie Meng
Summary: The study investigates nucleon effective masses in neutron-rich matter using the relativistic Brueckner-Hartree-Fock (RBHF) theory in the full Dirac space. The effective masses of neutrons and protons in symmetric nuclear matter are consistent with empirical values. In neutron-rich matter, the neutron has a larger effective mass compared to the proton, and the predicted neutron-proton effective mass splittings at the empirical saturation density are related to the isospin asymmetry parameter. The study's results align with other ab initio calculations and constraints from nuclear reaction and structure measurements.
Article
Physics, Nuclear
E. Grodner, M. Kowalczyk, M. Kisielinski, J. Srebrny, L. Prochniak, Ch Droste, S. G. Rohozinski, Q. B. Chen, M. Ionescu-Bujor, C. A. Ur, F. Recchia, J. Meng, S. Q. Zhang, P. W. Zhao, G. Georgiev, R. Lozeva, E. Fiori, S. Aydin, A. Nalecz-Jawecki
Summary: The g factor of the isomeric I = 9(+) bandhead of Cs-128 was obtained through experimental measurements and compared with the particle-rotor model. The results suggest that Cs-128 exhibits a nonchiral geometry for the isomeric bandhead and has a chiral critical frequency.
Article
Physics, Nuclear
C. G. Wang, R. Han, C. Xu, H. Hua, R. A. Bark, S. Q. Zhang, S. Y. Wang, T. M. Shneidman, S. G. Zhou, J. Meng, S. M. Wyngaardt, A. C. Dai, F. R. Xu, X. Q. Li, Z. H. Li, Y. L. Ye, D. X. Jiang, C. G. Li, C. Y. Niu, Z. Q. Chen, H. Y. Wu, D. W. Luo, S. Wang, D. P. Sun, C. Liu, Z. Q. Li, N. B. Zhang, R. J. Guo, P. Jones, E. A. Lawrie, J. J. Lawrie, J. F. Sharpey-Schafer, M. Wiedeking, S. N. T. Majola, T. D. Bucher, T. Dinoko, B. Maqabuka, L. Makhathini, L. Mdletshe, O. Shirinda, K. Sowazi
Summary: The spectroscopy of Ge-71 was investigated and the first experimental evidence of an octupole rotational band in Ge isotopes was found, suggesting enhanced octupole correlation around N = 40 in the A approximate to 70 region.
Article
Physics, Multidisciplinary
J. Z. Han, C. Pan, K. Y. Zhang, X. F. Yang, S. Q. Zhang, J. C. Berengut, S. Goriely, H. Wang, Y. M. Yu, J. Meng, J. W. Zhang, L. J. Wang
Summary: This study successfully extracts accurate nuclear charge radii values through precise measurement and analysis of isotope shifts, which is of great significance for the development of nuclear physics models.
PHYSICAL REVIEW RESEARCH
(2022)