物理最新文献

We theoretically investigate the induced transparency phenomenon in a hybrid double-cavities magnon-optomechanical system. A ferromagnetic material yttrium iron garnet (YIG) sphere and a mechanical resonator are placed in one of the microwave cavities, and the other is coupled to a mechanical phonon. We observe not only magnetically induced transparency (MIT) generated by magnon–photon interaction, but also magnomechanically induced transparency (MMIT) produced by nonlinear phonon–magnon interaction. It is shown that better transparency effect is obtained by appropriately adjusting the tunneling coupling strength. The effect of the interaction of the two mechanical resonators with the two microwave cavities on the output spectrum is discussed separately. In addition, we have established a new scheme to measure the mechanical phonon–photon coupling strength. We also investigated the effect of the cavity decay rate on the output field and found that better transparency can be obtained by appropriately reducing the decay rate of the cavity. We further explored the fast and slow light conversion phenomenon. These results have potential applications in quantum information processing and high precision measurements.

Measles continues to be a significant contributor to child mortality worldwide, causing thousands of deaths each year, even though a safe and effective vaccine is available. In recent years, global measles cases have risen significantly, with the majority of infections occurring in children under 5 years old and immunocompromised adults. The presented study introduces a novel autoregressive exogenous neuro-computing framework, enhanced through optimization by the Levenberg–Marquardt scheme, to model the dynamics of nonlinear stochastic measles transmission epidemic systems, considering the effects of immunization. The mathematical representations are formulated using multi-class stochastic differential compartments, describing the susceptible, immunized, exposed, infected, recovered individuals, and hospitalized cases. Synthetic data for executing the multi-layer structure of the autoregressive exogenous neuro-computing framework model are created using the Milstein method across various scenarios of the stochastic measles model, involving variation in key parameters such as rates of susceptible individuals, contact among susceptible people, immunization, mortality, infection, medical treatment, recovery, and natural death. The generated data are randomly partitioned into response and prediction sets for use in the testing, validation, and training phases of the autoregressive exogenous neuro-computing networks. The results from the designed approach exhibit a close correlation with the reference solutions, with negligible error magnitudes across all scenarios of the stochastic measles transmission model. The proposed approach is validated through convergence analyses using mean squared error, visual representations of adaptive governing parameters, error histograms, and regression indices for various nonlinear stochastic measles transmission models within mathematical biology.

Recently, the construction of µ⁺e⁻ and µ⁺µ⁺ colliders, μTRISTAN, at KEK has been proposed. We argue that the construction of a similar μ⁺ ring tangential to LHC/Tevatron/FCC/SppC will give an opportunity to realize µ⁺p and µ⁺A collisions at multi-TeV scale center-of-mass energies. In this paper, the main parameters of proposed colliders have been studied. It is shown that sufficiently high luminosities can be achieved for all proposals under consideration: L exceeds 10³³ cm⁻² s⁻¹ for µ⁺p colliders and 10³⁰ cm⁻² s⁻¹ for µ⁺A colliders. Certainly, proposed colliders will provide huge potential for both SM (especially QCD basics) and BSM physics searches.

This research introduces a novel application of three-dimensional (3D) combustion thermometry through the thermally-assisted volumetric laser-induced fluorescence, namely the TAVLIF technique. The TAVLIF method is designed to provide quantitative 3D temperature diagnostics using a single dye-laser system, combining the advantage of tomographic imaging with the thermally-assisted LIF approach. The technique employs the A²Σ⁺←X²Π (0, 0) band Q₁(7) transition to excite OH radicals within a controlled Bunsen burner flame. Following excitation, the fluorescence emitted from the resonant (0, 0) and non-resonant (1, 0) vibrational bands is captured sequentially by an intensified camera, facilitating the reconstruction of the 3D fluorescence field. Utilizing the axisymmetric and stable properties of the burner flame, we reconstruct the 3D distribution of fluorescence signals from both bands. The resulting 3D temperature field is determined by the ratio of fluorescence intensities between the two bands, employing a novel ternary model calibrated experimentally to relate temperature to fluorescence ratio. After accounting for acquisition errors such as reflection and scattering of excitation light, as well as reconstruction and temperature calculation errors, the relative error remains below 6%. This research demonstrates the cost-effectiveness (only one dye laser system), accuracy, and reliability of the TAVLIF technique in diagnosing 3D temperature fields within combustion processes.

The Taishan Antineutrino Observatory (TAO) is a liquid-scintillator satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO) to measure the reference reactor neutrino spectrum with unprecedented energy resolution. We use inhomogeneous Poisson process and Tweedie generalized linear model (GLM) to characterize the detector response and the charge distribution of a SiPM. We develop a pure probabilistic model for time and charge of SiPMs from first principles to reconstruct point-like events in the TAO central detector. Thanks to our precise model and the high photo-coverage and quantum efficiency of the SiPM tiles at TAO, we achieve vertex position resolution better than (20,hbox {mm}), energy resolution of about (2%) at (1,hbox {MeV}) and (<0.5%) non-uniformity, marking the world’s best performance of liquid scintillator detectors. With such resolution, we perceive (hbox {MeV}) events to exhibit track effects. It opens up an exciting possibility of computed tracking calorimeter for unsegmented liquid scintillator detector like TAO. Our methodology is applicable to other experiments that utilize PMTs for time and charge readouts.

This research derives the new solitons for the fluid wave model, a nonlinear Kadomtsev–Petviashvili-modified equal width model along truncated M-fractional derivative. Our concerned model is utilized to explain the matter-wave pulses, waves in ferromagnetic media, and long wavelength water waves with frequency dispersion and faintly nonlinear reinstating forces, and others. To this end, we apply the modified extended direct algebraic and the improved ((G'/G))-expansion techniques. Fractional transformation is utilized to convert the nonlinear fractional partial differential equation into a nonlinear ordinary differential equation. Mathematica software is used to gain the solutions, verify them, and demonstrate them in two-, three-dimensional, and contour plots. The impact of fractional derivative is represented through two-dimensional plot. A linear stability process is conducted to confirm that governing equation is stable. The techniques are reliable to use and provide the various types of solutions.

We apply the Kosambi–Cartan–Chern theory to perform an extensive examination of Jacobi stability of geodesics around rotating black hole solutions to dynamical Chern–Simons gravity, a theory that introduces modifications to General Relativity via a scalar field non-minimally coupled to curvature scalars. We present a comparative study between Jacobi and Lyapunov stability, pointing out the advantages of the more geometrical method over the usual Lyapunov approach.

The detection of gravitational waves (GW) from astrophysical sources has opened a new era in physics. However, advances in high-energy laser systems make it possible to consider gravitational waves produced in the laboratory. In this work, the angular distribution and energy flux of gravitational waves radiated by high-power Laguerre–Gaussian beams are analysed. With a power of (10^{22}~text {W}/text {cm}^2) and frequency of (10^{15}) Hz for the LG beams, the radiated GW frequency is twice the laser frequency and the maximal GW amplitude can reach (10^{-34},) which is quite small compared with the current detection threshold of around (10^{-21}) by LIGO. It is shown in Ejlli et al. (Eur Phys J C 79:1032, 2019) that the inverse Gertsenshtein effect is able to detect ultra high frequency gravitational wave with frequency up to (10^{15}) Hz and strain around (10^{-30},) which may provide a viable way to measure gravitational waves produced by high-power lasers in the future.

(111)-oriented 5%La: HfO₂ (HLO) thin films have been successfully deposited on La_0.67Sr_0.33MnO₃ buffered (111)-oriented SrTiO₃ (STO) substrates by pulsed laser deposition. The growth of the orthorhombic HLO films with a rhombohedral distortion follows a domain matching epitaxy mechanism and twin domains appear as revealed by atomic resolution scanning transmission electron microscopy. These (111)-oriented HLO films show 6-fold in-plane symmetry due to the twin domains rotated 180° to each other around the surface normal. The HLO films, 15 nm in thickness, on (111)-oriented STO exhibit robust ferroelectric properties with an optimized remanent polarization around 13 µC/cm² without any wake-up process.