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The European Physical Journal C 2024年第6期84卷 1-15页

作者： Yang, Jin-Lei Zhang, Hai-Bin Feng, Tai-Fu Department of Physics Hebei University Baoding China Key Laboratory of High-Precision Computation and Application of Quantum Field Theory of Hebei Province Baoding China Research Center for Computational Physics of Hebei Province Baoding China

A flavor-dependent model (FDM) is proposed in this work. The model extends the Standard Model by an extra $$U(1)_F$$ local gauge group, two scalar doublets, one scalar singlet and two right-handed neutrinos, where the additional $$U(1)_F$$ charges are related to the particles’ flavor. The new fermion sector in the FDM can explain the flavor mixings puzzle and the mass hierarchy puzzle simultaneously, and the nonzero Majorana neutrino masses can be obtained naturally by the Type I see-saw mechanism. In addition, the B meson rare decay processes $${\bar{B}} \rightarrow X_s\gamma ,$$ $$B_s^0 \rightarrow \mu ^+\mu ^-,$$ the top quark rare decay processes $$t\rightarrow ch,$$ $$t\rightarrow uh$$ and the $$\tau $$ lepton flavor violation processes $$\tau \rightarrow 3e,$$ $$\tau \rightarrow 3\mu ,$$ $$\mu \rightarrow 3e$$ predicted in the FDM are analyzed.

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Elemental topological ferroelectrics and polar metals of few-layer materials

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Physical Review Research 2024年第2期6卷 023208-023208页

作者： Hu Zhang Lulu Zhao RuiFeng Zhang Chendong Jin Ruqian Lian Peng-Lai Gong RuiNing Wang JiangLong Wang Xing-Qiang Shi Key Laboratory of Optic-Electronic Information and Materials of Hebei Province Research Center for Computational Physics of Hebei Province Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory College of Physics Science and Technology

Ferroelectricity can exist in elemental phases as a result of charge transfers between atoms occupying inequivalent Wyckoff positions. We investigate the emergence of ferroelectricity in two-dimensional elemental materials with buckled honeycomb lattices. Various multibilayer structures hosting ferroelectricity are designed by stacking engineering. Ferroelectric materials candidates formed by group IV and V elements are predicted theoretically. Ultrathin Bi films show layer-stacking-dependent physical properties of ferroelectricity, topology, and metallicity. The two-bilayer Bi film with a polar stacking sequence is found to be an elemental topological ferroelectric material. Three and four bilayers Bi films with polar structures are ferroelectriclike elemental polar metals with topological nontrivial edge states. For Ge and Sn, trivial elemental polar metals are predicted. Our work reveals the possibility of designing two-dimensional elemental topological ferroelectrics and polar metals by stacking engineering.

关键词： Ferroelectricity First-principles calculations Topological materials 2-dimensional systems Honeycomb lattice Topological insulators Density functional theory Symmetries in condensed matter

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Scalar neutrino dark matter in the BLMSSM

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Chinese Physics C 2021年第9期45卷 73-80页

作者： Ming-Jie Zhang Shu-Min Zhao Xing-Xing Dong Zhong-Jun Yang Tai-Fu Feng Department of Physics Hebei UniversityBaoding 071002China Key Laboratory of High-precision Computation and Application of Quantum Field Theory of Hebei Province Baoding 071002China Department of Physics Chongqing UniversityChongqing 401331China

The BLMSSM is an extension of the minimal supersymmetric standard model(MSSM).Its local gauge group is SU(3)C×SU(2)L×U(1)Y×U(1)B×U(1)*** the lightest scalar neutrino is a dark matter candidate,we study the relic density and the spin independent cross section of sneutrino scattering off a *** calculate the numerical results in detail and find a suitable parameter *** numerical discussion can confine the parameter space and provide a reference for dark matter research.

关键词： dark matter sneutrino supersymmetry

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Strong decays of the isovector-scalar D*D¯* hadronic molecule

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Physical Review D 2024年第5期110卷 054014页

作者： Jin-Cheng Deng Bo Wang College of Physics Science and Technology Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory Baoding 071002 China Hebei Research Center of the Basic Discipline for Computational Physics Baoding 071002 China

We adopt the effective Lagrangian approach to study the strong decays of the 1−(0++)D*D¯* molecular state [denoted as Tψ0a(4010) according to the LHCb naming convention] through triangle diagrams. The decay channels include the open-charm DD¯, and the hidden-charm ηcπ, J/ψρ, and χc1π. The coupling between the Tψ0a(4010) and its constituents D*D¯* is obtained by solving for the residue of the scattering T-matrix at the pole. Our calculations yield a total width of few tens MeV for the Tψ0a(4010) state using three different form factors, with its main decay channels being ηcπ and χc1π. The X(4100) and X(4050) have similar masses and widths, with both masses being close to the D*D¯* threshold. Additionally, their decay final states are consistent with those of the Tψ0a(4010). Therefore, it is likely that they represent the same state and both potentially correspond to the Tψ0a(4010). We suggest that future experiments focus on searching for the Tψ0a(4010) signal in the final states ηcπ−, χc1π−, and D0D− of the B0→ηcπ−K+, χc1π−K+, and D0D−K+ processes, respectively, as well as further investigating its resonance parameters with Flatté-like formula.

关键词： Hadron-hadron interactions Hadronic decays Multiquark bound states

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通过键共价性增加策略获得高性能Cu_(3)SbSe_(4)基热电材料

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Science China Materials 2023年第9期66卷 3644-3650页

作者：张旦钟瑞奇高仕康杨磊徐芳何平柳冠楠伞星源杨君友罗裕波王淑芳 Key Laboratory of High-precision Computation and Application of Quantum Field Theory of Hebei Province College of Physics Science and TechnologyHebei UniversityBaoding 071002China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

通过Cu_(3)SbSe_(4)-MTe (M=Ge/Sn)固溶体系的对比研究,本文报道了一种增加键共价性来弱化电声耦合进而获得高迁移率的策略,也证实了该策略能提升Cu_(3)SbSe_(4)化合物的热电性能.研究发现,相比于SnTe固溶,GeTe固溶赋予Cu_(3)SbSe_(4)... 详细信息

通过Cu_(3)SbSe_(4)-MTe (M=Ge/Sn)固溶体系的对比研究,本文报道了一种增加键共价性来弱化电声耦合进而获得高迁移率的策略,也证实了该策略能提升Cu_(3)SbSe_(4)化合物的热电性能.研究发现,相比于SnTe固溶,GeTe固溶赋予Cu_(3)SbSe_(4)化合物在相似载流子浓度情况下更高的迁移率,进而获得更优越的电输运性能.密度泛函理论计算表明,与SnTe固溶相比,GeTe固溶能增加Cu_(3)SbSe_(4)化学键共价性因而具有优越的电输运性能.最终,在Cu_(3)SbSe_(4)-1%GeTe样品中取得了0.8的最大热电优值(@648 K)和0.41的平均热电优值(300–648 K).此研究表明,通过增加键共价性来弱化电声耦合进而获得高迁移率是提升热电性能的有效途径.

关键词：密度泛函理论计算共价性热电性能热电优值高迁移率热电材料载流子浓度

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Origin of the tiny energy gap and Dirac points in monoclinic trilayer nickelate La4Ni3O10

arXiv

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arXiv 2025年

作者： Zhang, Hu Hebei Research Center of The Basic Discipline for Computational Physics Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory College of Physics Science and Technology Hebei University Baoding071002 China

Superconductivity was recently found in trilayer nickelate La4Ni3O10 under high pressure with a phase transition from the monoclinic P21/a structure to the tetragonal I4/mmm structure. Previous experimental works have confirmed the existence of a tiny energy gap formed with Ni 3dz2 orbitals in monoclinic La4Ni3O10. Here we investigate the physical origin of this gap by analyzing symmetry properties of energy bands based on the group theory. The tiny gap comes from energy bands with opposite parity at the Brillouin zone center. In addition, we also find previously unknown Dirac points in some momentum directions around the Fermi level. An effective Hamiltonian is constructed to describe low energy physics of the tiny energy gap and Dirac points. Due to the low crystal symmetry of monoclinic La4Ni3O10, its energy bands display strong anisotropic properties. © 2025, CC BY.

关键词： Hamiltonians

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First order corrections to black hole thermodynamics: A simple approach enhanced

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Physical Review D 2024年第10期110卷 104043-104043页

作者： Yong Xiao Yue-Ying Liu Key Laboratory of High-precision Computation and Application of Quantum Field Theory of Hebei Province College of Physical Science and Technology Hebei University Baoding 071002 China and Hebei Research Center of the Basic Discipline for Computational Physics Baoding 071002 China

The inclusion of higher derivative terms in the gravitational action brings about corrections to the original forms of black hole solutions and thermodynamics. A simple and valuable approach emerged over two decades ago, which states that the first order corrections to black hole thermodynamics, caused by higher derivative terms, can be achieved without explicitly solving the perturbed metric. However, a direct application of this approach may potentially yield incorrect answers as it comes to anti-de Sitter (AdS) black holes, which poses a challenge to the valuable approach. In this paper, we identify that the subtlety associated with AdS black holes is that certain higher derivative terms may alter the asymptotic structure of the spacetime. By taking this subtlety into account, we successfully enhance the original approach and resolve the mentioned problem. Furthermore, we make an interesting observation that the extremalization analysis that underlies this approach also plays a fundamental role in the perturbation theories of quantum mechanics and other disciplines.

关键词： Alternative gravity theories quantum aspects of black holes quantum gravity

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Relativistic effects in the strong and electromagnetic decays of the meson

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The European Physical Journal C 2025年第3期85卷 1-7页

作者： Jia, Man Li, Wei Pei, Su-Yan Du, Xin-Yao Ning, Guo-Zhu Wang, Guo-Li Department of Physics Hebei University Baoding China Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory Hebei University Baoding China Hebei Research Center of the Basic Discipline for Computational Physics Hebei University Baoding China College of Science Hebei Agriculture University Baoding China

In this paper, we solve the complete Salpeter equation and use the obtained relativistic wave function to calculate the strong and radiative electromagnetic decays of the $${D^*}$$ meson. We obtain the results $$\Gamma (D^{*}(2007)^{0}\rightarrow D^{0}\pi ^{0})=34.6~\textrm{keV}$$ and $$\Gamma (D^{*}(2007)^{0}\rightarrow D^{0}\gamma )=19.4~\textrm{keV}$$ , and the estimated full width is $$\Gamma (D^{*}(2007)^{0})=54.0~\textrm{keV}$$ . The focus of this study is on the relativistic corrections. In our method, the wave function of the D meson is not a pure S-wave, but includes both a non-relativistic S-wave and a relativistic P-wave, while the wave function of the $$D^*$$ meson includes a non-relativistic S-wave as well as both relativistic P-wave and D-wave. Therefore, in this case, the decay $${D^{*}\rightarrow {D}\gamma }$$ is not a non-relativistic M1 transition, but rather an $$M1+E2+M3+E4$$ decay. We find that in a strong decay $$D^{*}\rightarrow {D}{\pi }$$ , the non-relativistic contribution is dominant, while in an electromagnetic decay $${D^{*}\rightarrow {D}\gamma }$$ , the relativistic correction is dominant.

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Neutrinos in the flavor-dependent U(1)F model

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Physical Review D 2024年第11期110卷 115007-115007页

作者： Jin-Lei Yang Department of Physics Hebei University Baoding 071002 China Key Laboratory of High-precision Computation and Application of Quantum Field Theory of Hebei Province Baoding 071002 China and Research Center for Computational Physics of Hebei Province Baoding 071002 China

The neutrino oscillation experiments provide definitive evidence of new physics beyond the Standard Model, and the neutrino mass-squared differences and flavor mixing have been precisely measured. This study examines the neutrino sector within the flavor-dependent U(1)F model, where the unique fermion sector can simultaneously address both the flavor mixing puzzle and the mass hierarchy puzzle. It is found that the lightest neutrino is naturally massless in this model, and the predicted neutrino mass-squared differences, flavor mixing angles, and Dirac CP phase agree well with the experimental measurements. Additionally, the effects of the Dirac CP phase and Majorana CP phase on the theoretical predictions of the neutrino transition magnetic dipole moments are analyzed.

关键词： Neutrino mixing Neutrinos Flavor symmetries Neutrino mass

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Elemental noncentrosymmetric superconductors

arXiv

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arXiv 2024年

作者： Zhang, Hu Research Center for Computational Physics of Hebei Province Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory College of Physics Science and Technology Hebei University Baoding071002 China

Superconductivity has been discovered in many materials including elements, cuprates and nickelates. Noncentrosymmetric superconductors get attention due to their physical properties results from spatial inversion symmetry breaking. Here we propose the existence of elemental noncentrosymmetric superconductors which needs to break spatial inversion symmetry in single element phases realized by occupations of more than one Wyckoff positions. Elemental noncentrosymmetric superconductors allow us to study the admixture of spin-singlet and spin-triplet pairing states in elements with simple crystal structures and chemical conditions. We find that four-layer La thin films coming from bulk α-La with a double hexagonal close-packed structure are elemental noncentrosymmetric superconductors since the dimension reduction breaks the spatial inversion symmetry. In the normal state, four-layer La is a polar rare-earth metal with a spontaneous polarization having a polar layer group like ferroelectrics. Hence, to be more precise, four-layer La can also be called the elemental polar superconductor in the superconductivity state. Based on this method of breaking inversion symmetry, we discovery polar rare-earth metals, polar transition metals, polar alkali metals and polar alkali earth metals. Other candidate materials are bulk polar materials formed with group 15 elements, Bi thin films with polar stacking, polar double layer plumbene and Al thin films. The question of building the periodic table of elemental noncentrosymmetric superconductors is raised. © 2024, CC BY.

关键词： Rare earths

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