Chinese Journal of Physics最新文献

{"title":"Deformed boson statistics and primordial black hole production under slow expansion conditions","authors":"Mahnaz Maleki ,&nbsp;Farhad Sattari ,&nbsp;Soghra Mirershadi","doi":"10.1016/j.cjph.2025.06.046","DOIUrl":"10.1016/j.cjph.2025.06.046","url":null,"abstract":"<div><div>The Planck scale physics remains largely unexplored, and understanding the complete quantum theory of gravity may unveil the Universe mysteries that lie beyond this scale. This paper investigates the production of primordial black holes within a thermodynamic framework in an expanding Friedmann–Robertson–Walker (FRW) universe. We leverage the established principle that particle collisions can result in black hole formation when particles are confined within the Schwarzschild radius corresponding to their center of mass energy, a concept known as a variant of the hoop conjecture. Initially, we extend the hoop conjecture to apply to an expanding FRW universe. Our findings reveal that the critical formula derived is significantly influenced by the Hubble parameter, which describes the rate of cosmic expansion, and it effectively aligns with established spacetime limits. Subsequently, we utilize our generalized formula to compute the number density of black holes <span><math><mrow><mo>(</mo><msub><mrow><mi>n</mi></mrow><mrow><mi>bh</mi></mrow></msub><mo>)</mo></mrow></math></span> generated from particle collisions in the hot system of an early expanding FRW universe as a function of temperature and deformation parameter <span><math><mi>q</mi></math></span>. We propose that at certain temperatures, the density of black holes may dominate. Our analysis indicates that conditions beyond the Planck temperature are plausible under deformed bosonic statistics. Furthermore, we examine scenarios in the early universe when temperatures surpassed the Planck temperature, concluding that deformed statistics are consistent with the extremely high temperatures characteristic of that epoch. Although black holes may proliferate under these elevated thermal conditions, they are predicted to overshadow background radiation when temperatures beyond those typical at the Planck scale. This study contributes to our understanding of primordial black holes and their formation mechanisms in the context of an expanding universe, providing insights into conditions that may have existed shortly after the Big Bang. In fact, we examine the beyond Planck temperature in the early universe and deduce that deformed statistics are consistent with the extremely high temperatures present in the early universe.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"97 ","pages":"Pages 284-301"},"PeriodicalIF":4.6,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144713582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Darcy–Forchheimer flow driven by membrane pumping and magnetohydrodynamics: perturbation solution","authors":"Pankaj Jangid ,&nbsp;Abhishesh Pandey ,&nbsp;Dharmendra Tripathi ,&nbsp;Kalpna Sharma","doi":"10.1016/j.cjph.2025.06.004","DOIUrl":"10.1016/j.cjph.2025.06.004","url":null,"abstract":"<div><div>Membrane based pumping addresses the critical need for precise fluid control in biomedical applications, particularly in targeted drug delivery, dialysis, and biofluid circulation, by investigating magnetohydrodynamic (MHD) fluid flow in porous microchannels. The aim of this study is to develop a Darcy–Forchheimer-based MHD pumping model to analyze transient viscous fluid flow through a finite-length microchannel. The methodology involves modelling the upper wall of the channel as undergoing rhythmic, propagative membrane contractions to replicate physiological transport mechanisms and lower wall is stationary. A perturbation technique is employed to derive the analytical series solution, using lubrication theory and assuming a low Reynolds number. The effects of key parameters including the membrane shape parameter, Hartmann number, inverse Darcy number and Forchheimer number are examined on flow and pumping characteristics, shear stress and streamline patterns using MATLAB code. The results highlight that velocity reduces with increasing the Forchheimer number and Hartmann number due to enhanced inertial and Lorentz forces. In the microchannel, the maximum pressure difference is observed at the region where the membrane is located, highlighting the effectiveness of the pumping mechanism. The significance of this study lies in its contribution to the advancement of MHD-based biomedical micropumps, providing valuable insights into controlled fluid transport within microfluidic systems. These findings are especially important for enhancing the controlled and smooth process of biofluid dynamics at microscale without any contamination, and addressing critical challenges in biomedical engineering.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"96 ","pages":"Pages 1435-1452"},"PeriodicalIF":4.6,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spontaneous emission in an exponential model","authors":"A.D. Kammogne,&nbsp;L.C. Fai","doi":"10.1016/j.cjph.2025.07.006","DOIUrl":"10.1016/j.cjph.2025.07.006","url":null,"abstract":"<div><div>The phenomenon of spontaneous emission can lead to the creation of an imaginary coupling and a shift. To explore this, we utilize the renormalized first Nikitin model, which features an exponential detuning variation with a phase, an imaginary coupling, and a shift. By employing the time-dependent Schrödinger equation, we investigate the behavior of our system. Our findings indicate that the imaginary coupling provides specific insights, while the shift gives rise to allowed and forbidden zones in the energy diagram of the real part of the energy. In the diagram of the imaginary part of the energy, time determines whether the system exhibits order or chaos and helps identify the information transmission zone. Notably, the first Nikitin model exhibits similarities to the Rabi model in the short-time approximation. Our theoretical results are consistent with numerical simulations.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"97 ","pages":"Pages 486-495"},"PeriodicalIF":4.6,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing a novel neutral heavy gauge boson within the mono-Z′ portal at the HL-LHC","authors":"Ali M. Hamed ,&nbsp;El-sayed A. El-dahshan ,&nbsp;S. Elgammal","doi":"10.1016/j.cjph.2025.07.005","DOIUrl":"10.1016/j.cjph.2025.07.005","url":null,"abstract":"<div><div>This study examines the production of dark matter events in association with a <span><math><msup><mrow><mi>Z</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span> boson decaying via leptonic channels in simulated proton–proton collisions at the Large Hadron Collider. The analysis focuses on collisions at a center-of-mass energy of <span><math><mrow><msqrt><mrow><mi>s</mi></mrow></msqrt><mo>=</mo><mn>14</mn><mspace></mspace><mtext>TeV</mtext></mrow></math></span> under high-luminosity conditions, corresponding to an integrated luminosity of <span><math><mrow><mn>1000</mn><mspace></mspace><msup><mrow><mtext>fb</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>. Using Monte Carlo simulations interpreted within the Effective Field Theory (EFT) framework, this work investigates potential signatures of new physics. In the absence of such signals, upper limits are set on key EFT parameters, including the theory’s cutoff scale and the mass of the <span><math><msup><mrow><mi>Z</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span> boson.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"97 ","pages":"Pages 100-108"},"PeriodicalIF":4.6,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144662244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic properties of a hexagonal Ising nanowire with spin-1/2 core and spin-5/2 shell","authors":"I.A. Badrour,&nbsp;H. Saadi,&nbsp;N. Hachem,&nbsp;M. El Bouziani","doi":"10.1016/j.cjph.2025.06.042","DOIUrl":"10.1016/j.cjph.2025.06.042","url":null,"abstract":"<div><div>Using a mean-field approach, we investigated the magnetic characteristics and phase diagrams of a hexagonal Ising nanowire with a spin-1/2 core and a spin-5/2 shell in a ferrimagnetic configuration. We examined the impacts of crystal field and exchange interactions on the critical and magnetic behaviors of the nanowire. The results reveal the emergence of first- and second-order phase transitions, critical isolated end-points, and compensation temperatures. The properties identified could be fascinating for the technological uses of these nanowires.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"96 ","pages":"Pages 1410-1419"},"PeriodicalIF":4.6,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144632011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Local error estimate of L1 scheme for time-fractional convection–diffusion–reaction equation on a star-shaped pipe network","authors":"Jingjia Wang,&nbsp;Xiangyun Meng,&nbsp;Yongguang Yu","doi":"10.1016/j.cjph.2025.06.040","DOIUrl":"10.1016/j.cjph.2025.06.040","url":null,"abstract":"<div><div>It is a significant issue to study the discrete method for the time-fractional parabolic problem on the metric graph in scientific computation. In this paper, the time-fractional convection–diffusion–reaction problem with initial singularity on the metric star-shaped graph is considered. In order to overcome the weak singularity of the solution numerically, a L1-finite difference method over the metric graph is constructed by using the graded temporal mesh and uniform spacial mesh. More specific, L1 scheme is employed for temporal discretization of the Caputo fractional-derivative. Also, the finite difference method is proposed for spacial discretization by applying the technique of ghost points to discretize the Robin–Kirchhoff condition at the intersection point and the boundary conditions. Through this method, the second-order truncation accuracy in space is obtained. Over the entire star graph, a sharp error estimate of this full-discrete scheme at each time level is demonstrated. Meanwhile, the convergence analysis for a preserving Robin–Kirchhoff condition scheme at each time step is given. Numerical results are presented to confirm the sharpness of the theoretical analysis.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"97 ","pages":"Pages 44-66"},"PeriodicalIF":4.6,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144654368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized oracle and diffusion operator implementations for enhanced quantum search performance","authors":"Tarun Kumar ,&nbsp;Dilip Kumar ,&nbsp;Gurmohan Singh","doi":"10.1016/j.cjph.2025.07.014","DOIUrl":"10.1016/j.cjph.2025.07.014","url":null,"abstract":"<div><div>Searching for an item in an unstructured database with Grover's search algorithm (<em>GSA</em>) guarantees a quadratic improvement in speed compared to classical approaches. One of the challenges in implementing <em>GSA</em> is the need for a large number of gates, which can be resource-intensive and error-prone. This paper presents a novel optimization of <em>GSA</em> that minimizes the complexity by reducing the gate count and circuit depth of the oracle and diffusion operator. A 47 % and 49 % reduction in gate count and circuit depth is observed for the 3-, 4-, and 5-qubit implementations of the optimized <em>GSA</em> against the standard version. Furthermore, the optimized <em>GSA</em> is utilized to perform a search in a quantum database for the index of <span><math><mrow><mo>|</mo><mn>111</mn><mo>〉</mo></mrow></math></span>. The results also indicate a significant improvement in the accuracy and execution time for the 3-, 4-, and 5-qubit implementations, and for searching a quantum database with the optimized <em>GSA</em> against the standard <em>GSA</em>.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"97 ","pages":"Pages 920-932"},"PeriodicalIF":4.6,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144829514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal analysis and entropy generation on time-dependent two-phase immiscible non-Newtonian nanofluids through porous tube under electromagnetic effects with slip velocity","authors":"Sangeetha J. ,&nbsp;Ponalagusamy R.","doi":"10.1016/j.cjph.2025.06.015","DOIUrl":"10.1016/j.cjph.2025.06.015","url":null,"abstract":"<div><div>The present research scrutinized the numerical simulations on the thermal effects of multiphase flow of immiscible Sutterby-Jeffrey nanofluids in a circular cylinder along with slip velocity through the porous region. The influence of Palladium (<span><math><mrow><mi>P</mi><mi>d</mi></mrow></math></span>) nanoparticles with distinct shapes was studied, proceeding with hexahedron (<span><math><mrow><msub><mrow><mi>n</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>=</mo><mn>3</mn><mo>.</mo><mn>72</mn></mrow></math></span>) shape. The conduit is maintained to be isothermal and the governing equations are constructed for the continuity, momentum, energy and entropy equations along with continuity in the interfacial regions. The different combinations of base fluids Ethylene Glycol and mineral oil are explained and it is certainly proven that Ethylene Glycol performs better than Mineral oil. The dimensionless equations governing each layer were numerically integrated using the finite difference method with the Crank–Nicolson approach. A mesh independence and validation results are conducted. Furthermore, a parametric study is performed under three conditional cases involving the Sutterby parameter, Grashof number, electromagnetic field, and Prandtl number. The comparison was made between <span><math><mrow><mi>P</mi><mi>d</mi></mrow></math></span>, <span><math><mrow><mi>T</mi><mi>i</mi><msub><mrow><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> and <span><math><mrow><mi>A</mi><mi>u</mi></mrow></math></span> nanoparticles for the velocity profile and found that the effectiveness of Pd nanofluids was much more efficient than the Au and <span><math><mrow><mi>T</mi><mi>i</mi><msub><mrow><mi>O</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span> nanofluids. A binate circumstance was observed in the Bejan number under conditional cases. Meanwhile, the Sutterby parameter and Jeffrey parameter enhanced the entropy generation. In addition, the entropy in region I was less compared to Region II whereas the opposite behaviour was perceived in the velocity profiles.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"97 ","pages":"Pages 532-562"},"PeriodicalIF":4.6,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144750085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiphase flow of three immiscible non-Newtonian fluids through porous cylindrical annulus under magnetic field","authors":"Satish Kumar ,&nbsp;Satya Deo ,&nbsp;Pankaj Kumar Maurya ,&nbsp;Pawan Kumar Patel","doi":"10.1016/j.cjph.2025.06.047","DOIUrl":"10.1016/j.cjph.2025.06.047","url":null,"abstract":"<div><div>The present work concerns the flow of three immiscible non-Newtonian fluids: a couple stress fluid, a micropolar fluid and a Jeffery fluid through a cylindrical pipe under applied uniform magnetic field in the direction perpendicular to the flow. The Jeffery fluid flows through the deepest cavity, while the couple stress fluid and the micropolar fluid flow through the outer and middle cylindrical shells, respectively. Jeffery’s equations of motion govern the flow of Jeffery fluid, while the well-known Brinkman equation and Eringen’s field equations govern the movement of couple stress fluid and micropolar fluid, respectively. Analytical expressions for microrotational velocity, flow rate, shear and couple stresses, and velocity are obtained using appropriate boundary conditions. Graphical and detailed studies have been made on the effects of several parameters on fluid velocity, microrotational velocity, couple stress, and flow rate. These parameters include porosity, permeability, couple stress, micropolar, viscosity ratios, and electrical conductivity ratios.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"97 ","pages":"Pages 15-43"},"PeriodicalIF":4.6,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144654367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum mechanical analysis of cesium dimer, titanium hydride, and titanium carbide: Vibrational spectra, expectation values, and information-theoretic measures","authors":"Etido P. Inyang ,&nbsp;N. Ali ,&nbsp;R. Endut ,&nbsp;N.R. Yusof ,&nbsp;S.A. Aljunid ,&nbsp;M.A. Romli","doi":"10.1016/j.cjph.2025.07.010","DOIUrl":"10.1016/j.cjph.2025.07.010","url":null,"abstract":"<div><div>This study explores quantum systems governed by a hybrid potential model that combines the Möbius square and screened Kratzer potentials (MSSKP). The Schrödinger Eq. was solved analytically using the parametric Nikiforov–Uvarov (pNU) method to investigate the quantum properties of heteronuclear diatomic molecules such as titanium hydride (TiH) and titanium carbide (TiC). Information-theoretic measures—namely, Shannon entropy and Fisher information—were employed to probe wavefunction delocalization and electron density localization, respectively. Expectation values were derived using the Hellmann–Feynman theorem. The results indicate that TiC exhibits stronger electron localization and covalent bonding compared to TiH. Moreover, the vibrational energy levels of the cesium dimer (Cs₂) were calculated and showed excellent agreement with experimental Rydberg–Klein–Rees (RKR) data. Comparative analysis revealed that the MSSKP outperforms the Morse and Manning–Rosen potentials, achieving a minimum mean absolute error (MAE) of 0.0234 cm⁻¹, compared to 0.2364 cm⁻¹ and 0.0517 cm⁻¹, respectively. This work underscores the synergy between quantum mechanical modeling and information theory, offering deeper insights into molecular structure, bonding, and quantum behavior relevant to quantum chemistry and nanophysics.</div></div>","PeriodicalId":10340,"journal":{"name":"Chinese Journal of Physics","volume":"97 ","pages":"Pages 471-485"},"PeriodicalIF":4.6,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}