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The radius variations of accreting main sequence stars and mass transfer instability

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arXiv 2024年

作者： Zhao, Zi-Qi Li, Zhen-Wei Xiao, Lin Ge, Hong-Wei Han, Zhan-Wen Department of Physics Hebei University Baoding071002 China Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory Baoding071002 China Hebei Research Center of the Basic Discipline for Computational Physics College of Physics Science and Technology Hebei University Baoding071002 China Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Science China International Centre of Supernovae Yunnan Key Laboratory Kunming650216 China University of the Chinese Academy of Science Yuquan Road 19 Shijingshan Block Beijing100049 China

Many previous works studied the dynamical timescale mass transfer stability criteria based on the donor response with neglecting the stellar structure of the accretor. In this letter, we investigate the radial response of accretors with mass accumulation and its effect on the binary mass transfer stability. We perform a series of detailed stellar evolution simulations with different types of accretors and obtain the radial variations of stars accreting at different rates. Since the time within which the donor loses half of the original mass has a correlation with the donor mass, we approximately obtain the mean mass transfer rate as a function of mass ratio. Assuming that the common envelope (CE) phase occurs if the accretor radius exceeds the outer Roche lobe radius, we obtain the critical mass ratio of dynamically unstable mass transfer. We find the critical mass ratios for donors filling their Roche lobes at the Main Sequence (MS) and Hertzsprung Gap (HG) stages are smaller than that derived from the radial response of the donor in the traditional way. Our results may suggest that the binary is easier to enter into the CE phase for a donor star at the MS or HG stage than previously believed. Copyright © 2024, The Authors. All rights reserved.

关键词： Mass transfer

Extended black hole thermodynamics from extended Iyer–Wald formalism

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arXiv 2023年

作者： Xiao, Yong Tian, Yu Liu, Yu-Xiao Key Laboratory of High-precision Computation Application of Quantum Field Theory of Hebei Province College of Physical Science and Technology Hebei University Baoding071002 China Hebei Research Center of the Basic Discpline for Computational Physics Baoding071002 China School of Physics University of Chinese Academy of Sciences Beijing100049 China Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China Key Laboratory for Quantum Theory and Applications The Ministry of Education Lanzhou Center for Theoretical Physics Lanzhou University Gansu Lanzhou730000 China

In recent years, there has been significant interest in the field of extended black hole thermodynamics, where the cosmological constant and/or other coupling parameters are treated as thermodynamic variables. Drawing inspiration from the Iyer-Wald formalism, which reveals the intrinsic and universal structure of conventional black hole thermodynamics, we illustrate that a proper extension of this formalism also unveils the underlying theoretical structure of extended black hole thermodynamics. As a remarkable consequence, for any gravitational theory described by a diffeomorphism invariant action, it is always possible to construct a consistent extended thermodynamics using this extended formalism. Copyright © 2023, The Authors. All rights reserved.

关键词： Thermodynamics

Double pole structures of X1(2900) as the P-wave D¯∗K∗ resonances

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arXiv 2024年

作者： Wang, Jun-Zhang Lin, Zi-Yang Wang, Bo Meng, Lu Zhu, Shi-Lin School of Physics Center of High Energy Physics Peking University Beijing100871 China School of Physics Peking University Beijing100871 China College of Physics Science & Technology Hebei University Baoding071002 China Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory Baoding071002 China Hebei Research Center of the Basic Discipline for Computational Physics Baoding071002 China Institut für Theoretische Physik II Ruhr-Universität Bochum BochumD-44780 Germany

We reveal the double pole structures of the manifestly exotic tetraquark state X1(2900) in the scenario of P-wave D¯∗K∗ dimeson resonance. We find that the observed enhancement signal associated with X1(2900) in B+ → D+D−K+ by LHCb contains two P-wave poles denoted as Tcs1−(2900) and Tcs′1−(2900), respectively. After considering the channel couplings among the D¯K, D¯∗K, D¯K∗ and D¯∗K∗ and the width of the K∗ meson, the masses and widths of the S-wave pole Tcs0+(2900) and two P-wave poles Tcs1−(2900) and Tcs′1−(2900) coincide with those of the X0(2900) and X1(2900) remarkably, which provides strong support for identifying X0(2900) and X1(2900) as D¯(∗)K(∗) dimeson states. Furthermore, we extensively calculate all S-wave and P-wave D¯(∗)K(∗) systems up to J = 3 and predict four new isoscalar charmed-strange dimeson-type tetraquark states: an S-wave state Tcs1+(2900) with quantum number JP = 1+, three P-wave states Tcs1−(2760) with JP = 1−, Tcs0−(2760) with JP = 0− and Tcs2−(2900) with JP = 2−. These near-threshold poles can be searched for at LHCb, Belle II and BESIII. Copyright © 2024, The Authors. All rights reserved.

关键词： Shear waves

The electromagnetic decays of X(3823) as the ψ2(13D2) state and its radial excited states

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arXiv 2022年

作者： Li, Wei Pei, Su-Yan Wang, Tianhong Wang, Ying-Long Feng, Tai-Fu Wang, Guo-Li Department of Physics and Technology Hebei University Baoding071002 China Key Laboratory of High-precision Computation Application of Quantum Field Theory of Hebei Province Baoding China School of Physics Harbin Institute of Technology Harbin150001 China Department of Preschool Teacheers College Baoding072750 China

We study the electromagnetic (EM) decays of X(3823) as the ψ2(13D2) state by using the relativistic Bethe-Salpeter method. Our results are Γ[X(3823) → χc0γ] = 1.2 keV, Γ[X(3823) → χc1γ] = 265 keV, Γ[X(3823) → χc2γ] = 57 keV and Γ[X(3823) → ηcγ] = 1.3 keV. The ratio B[X(3823) → χc2γ]/B[X(3823) → χc1γ] = 0.22, agrees with the experimental data. Similarly, the EM decay widths of ψ2(n3D2), n = 2,3, are predicted, and we find the dominant decays channels are ψ2(n3D2) → χc1(nP)γ, where n = 1,2,3. The wave function include different partial waves, which means the relativistic effects are considered. We also study the contributions of different partial waves. Copyright © 2022, The Authors. All rights reserved.

关键词： Excited states

Spectrum of the molecular hexaquarks

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arXiv 2024年

作者： Wang, Bo Chen, Kan Meng, Lu Zhu, Shi-Lin College of Physics Science and Technology Hebei University Baoding071002 China Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory Baoding071002 China Hebei Research Center of the Basic Discipline for Computational Physics Baoding071002 China School of Physics Northwest University Xi’an710127 China Institut für Theoretische Physik II Ruhr-Universität Bochum BochumD-44780 Germany School of Physics Center of High Energy Physics Peking University Beijing100871 China

We investigate the mass spectra of molecular-type hexaquark states in the dibaryon systems. These systems are composed of the charmed baryons [Σ(c∗), Ξc(′,∗)], doubly charmed baryons [Ξ(cc∗)], and hyperons [Σ(∗), Ξ(∗)]. We consider all possible combinations of particle-particle and particle-antiparticle pairs, including the S-wave spin multiplets in each combination. We establish the underlying connections among the molecular tetraquarks, pentaquarks, and hexaquarks with the effective quark-level interactions. We find that the existence of molecular states in DD∗, DD¯∗, and ΣcD¯(∗) systems leads to the emergence of a large number of deuteron-like hexaquarks in the heavy flavor sectors. Currently, there have been several experimental candidates for molecular tetraquarks and pentaquarks. The experimental search for near-threshold hexaquarks will further advance the establishment of the underlying dynamical picture of hadronic molecules and deepen our understanding of the role of spin-flavor symmetry in near-threshold residual strong interactions. © 2024, CC BY.

关键词： Mass spectrometry

Study of two quasidegenerate heavy sterile neutrinos in rare meson decays

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Physical Review D 2021年第3期103卷 035015-035015页

作者： Jiabao Zhang Tianhong Wang Geng Li Yue Jiang Guo-Li Wang School of Physics Harbin Institute of Technology Harbin 150001 China Department of Physics Hebei University Baoding 071002 China Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory Baoding 071002 China

In this work, we study the lepton-number-violating processes of K± and D± mesons. Two quasidegenerate sterile neutrinos are assumed to induce such processes. Different from the case where only one sterile neutrino is involved, here, the CP phases of the mixing parameters could give a sizable contribution. This, in turn, would affect the absolute values of the mixing parameters determined by the experimental upper limits of the branching fractions. A general function which expresses the difference between the mixing parameters for two-generation and one-generation cases is presented. Special cases with specific relations of the parameters are discussed. Besides, we also thoroughly investigate the CP violation effect of such processes. It is shown that generally ACP is a function of the sterile neutrino mass.

关键词： Particle decays Sterile neutrinos CP violation

Accretion of matter by a Charged dilaton black hole

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arXiv 2024年

作者： Jia, Yinan He, Tong-Yu Wang, Wen-Qian Han, Zhan-Wen Yang, Rong-Jia College of Physical Science and Technology Hebei University Baoding071002 China College of Physics Science and Technology Hebei University Baoding071002 China Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Hebei Key Lab of Optic-Electronic Information and Materials Hebei University Baoding071002 China National-Local Joint Engineering Laboratory of New Energy Photoelectric Devices Hebei University Baoding071002 China Key Laboratory of High-pricision Computation and Application of Quantum Field Theory of Hebei Province Hebei University Baoding071002 China

Considering accretion onto a charged dilaton black hole, the fundamental equations governing accretion, general analytic expressions for critical points, critical velocity, critical speed of sound, and ultimately the mass accretion rate are obtained. A new constraint on the dilation parameter coming from string theory is found and the case for polytropic gas is delved into a detailed discussion. It is found that the dialtion and the adiabatic index of accreted material have deep effects on the accretion process. © 2024, CC BY-NC-SA.

关键词： Black holes

Types of the geodesic motions in Kerr-Sen-AdS4 spacetime

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arXiv 2023年

作者： Cai, Ziqiang He, Tong-Yu Wang, Wen-Qian Han, Zhan-Wen Yang, Rong-Jia College of Physics Science and Technology Hebei University Baoding071002 China Yunnan Observatories Chinese Academy of Sciences Kunming650216 China Hebei Key Lab of Optic-Electronic Information and Materials Hebei University Baoding071002 China National-Local Joint Engineering Laboratory of New Energy Photoelectric Devices Hebei University Baoding071002 China Key Laboratory of High-pricision Computation and Application of Quantum Field Theory of Hebei Province Hebei University Baoding071002 China

We consider the geodesic motions in the Kerr-Sen-AdS4 spacetime. We obtain the equations of motion for light rays and test particles. Using the parametric diagrams, we shown some regions where the radial and latitudinal geodesic motions are allowed. We analyse the impact of parameter related to dilatonic scalar on the orbit and find that it will result in more rich and complex orbital types. © 2023, CC BY-NC-SA.

关键词： Equations of motion

Rare top quark decays in the minimal R-symmetric supersymmetric standard model

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arXiv 2023年

作者： Sun, Ke-Sheng Wang, Zhi-Chuan Yang, Xiu-Yi Gao, Tie-Jun Zhang, Hai-Bin Department of Physics Baoding University Baoding071000 China Department of Physics Hebei University Baoding071002 China Key Laboratory of High-Precision Computation and Application Quantum Field Theory of Hebei Province Baoding071002 China Research Center for Computational Physics of Hebei Province Baoding071002 China School of science University of Science and Technology Liaoning Anshan114051 China School of Physics Xidian University Xi’an710071 China

The one-loop contributions to the flavor-changing neutral current decays of the top quark into a light quark and a gauge boson or Higgs boson, namely t → qV, qh, with q being u or c, and V being γ, g, or Z, are analyzed in this study within the framework of the minimal R-symmetric supersymmetric standard model. The charginos in this model have been separated into two sets, i.e., χ-chargino and ρ-chargino. The numerical results reveal that gluino or ρ-chargino predominantly dictate the predictions for BR(t → qV, qh), while the impact of neutralino or χ-chargino contributions is insignificant. By incorporating the constraints imposed by the squark mixing parameters from B¯ → Xsγ and (Equation presented), the theoretical predictions for BR(t → qg) can be significantly augmented to approximately O(10−5 −10−6). On the other hand, the values of BR(t → qγ, qZ, qh) are predicted to be at least four orders of magnitude below the current experimental limits. Copyright © 2023, The Authors. All rights reserved.

关键词： Bosons