Physics Open最新文献

In this paper a sphere fiber bundle structure underlying the Standard Model of Particle Physics is developed. The developed bundle framework is shown to contain mathematical structures naturally suited for modeling the Standard Model’s elementary particles and fields.

This modeling yields numerous results across the spectrum of physics, including: a resolution to the family problem, explanation of the 6-6 lepton–quark split in nature, a spacetime structural explanation of dark matter and energy, prediction of repulsive gravitational effects occurring in localized regions of space maintained at energies $O\left(10^{15}K\right)$, a modeling of the SM elementary particles as vibrating closed loops in spacetime, elimination of the fermionic QFT VEV catastrophe, the unveiling of a grand unification model at odds with standard GUT models, prediction of Dirac-style magnetic monopoles and of a quark-gluon and quasi-quark-gluon plasma near inception of the universe, a topological explanation for quark confinement, resolution to the cosmological constant problem, and a presentation of the model’s topology of quantum entanglement which reconciles relativistic locality with quantum non-locality.

We find an exact closed-form expression for the magnetostatic interaction energy between a point magnet and a ring magnet in terms of complete elliptic integrals. The exact expression for the energy exhibits an equilibrium point close to the axis of symmetry of the ring magnet. Our methodology will be useful in investigations concerning magnetic levitation, and in the study of Casimir levitation.

In this work, we investigate the thermodynamic properties of $CrH,NiC$ and $CuLi$ diatomic molecules with a linear combination Hulthen and Yukawa potentials in the presence and absence of magnetic and Aharanov-Bohm (AB) fields. The Schrödinger equation in 3D and 2D were solved using the Nikiforov-Uvarov (NU) method and the exact quantization rule (EQR) respectively. To determine the thermodynamic properties for the selected diatomic molecules, we first used the energy spectrum to evaluate the partition function and other thermodynamic functions such as entropy, Helmholtz free energy, internal energy and specific heat capacity. In addition, it is found that in the classical limit, the specific heat capacity saturates for large values of the principal quantum number, $n_{\max }$ for the selected diatomic molecules at a fixed temperature except $CrH$. Our results can be applied to molecular physics and chemical physics.

In order to reduce water consumption (especially in remote areas) for the self-cleaning dust removal systems, the efficiency of a three-phase traveling electromagnetics wave for some designed Electrodynamics Dust Shield (EDS) setups are simulated and also experimentally tested. The designed Fresnel rings electrodes EDS system showed about 25% enhancement on light collecting power and a substantial improvement on dust removal efficiency, as well. On the other hand, for the fabricated EDS systems the dust removal efficiency has been tested as a function of the dust particle size, respectively. In this study, the removal dust particles has been sampled from three different Iran's desserts with a vast size ranges, which matches with many of the remote areas in the world. It was confirmed that the sweeping frequency range from 5 to 100 Hz improved the cleaning efficiency and also the sweeping time lasting reduced about half for the zigzag electrode EDS system in comparison to a simple parallel bar one. For designing the different EDS systems, the well-known Finite Element calculation method (COMSOL Multiphysics software) has been employed, respectively.

The present report deals with a modification of the nonlinear X-ray Compton scattering expression by introducing an index of refraction R. XFEL-based two hard X-ray photons with the energy $\omega$ around 9 keV were effectively mixed up to form a single high-energy photon (18 keV) in a prior publication (Fuchs et al., 2015). Using the Volkov correction, an alternative estimation of scattered X-ray photon energy ${\omega }^{\prime }$ via a nonlinear process was expressed. Applying this theoretical model, it was determined that an 18 keV single high-energy scattered photon can be produced by mixing two 9 keV photons with a field strength parameter $\chi$ ranging from 0.1 to 0.2.

Electron paramagnetic resonance, thermoluminescence, and optically stimulated luminescence, with biological tissues and inert materials are well established physical methods for retrospective dosimetry in acute accidental exposures. The objective of this article is to provide a view of the questions still open, the current challenges and the needed solutions. As research on emergency response methods is encountering increasing difficulties in terms of financial and human resources in many countries, it is essential to identify the research priorities and pay attention to cost-effective research paths. The intention of the paper is to stimulate discussion in the scientific community and to encourage collaboration among laboratories toward goals that address the real needs in retrospective dosimetry for acute exposures.

This paper deals with the spin-polarization change of an electron beam after elastic scattering with a neutral atom. The first part of the paper is devoted to summarizing the Kessler theory of the elastic scattering of spin-polarized electron beams. After a general description of the dependence on the polar and azimuthal angles of the spin-polarization after scattering, the effects on the spin-polarization of multiple elastic collisions occurring in the same scattering plane and with identical scattering angles are also treated. In particular, we show that, in this case, an initially unpolarized beam becomes fully polarized in the direction normal to the scattering plane after a number of collisions. The number of collisions necessary to reach full (transverse) polarization is a function of the common scattering angle. We also demonstrate that spin-polarization is conserved for forward and backward elastic scattering.

Quantum control optimization algorithms are routinely used to synthesize optimal quantum gates or to realize efficient quantum state transfers. The computational resource required for the optimization is an essential consideration in order to scale toward quantum control of larger registers. Here, we propose and demonstrate the use of a machine learning method, specifically the recommender system (RS), to deal with the challenge of enhancing computational efficiency. Given a sparse database of a set of products and their customer ratings, RS is used to efficiently predict unknown ratings. In the quantum control problem, each iteration of a numerical optimization algorithm typically involves evaluating a large number of parameters, such as gradients or fidelities, which can be tabulated as a rating matrix. We establish that RS can rapidly and accurately predict elements of such a sparse rating matrix. Using this approach, we expedite a gradient ascent based quantum control optimization, namely GRAPE, and demonstrate the faster construction of two-qubit CNOT gate in registers with up to 8 qubits. We also describe and implement the enhancement of the computational speed of a hybrid algorithm involving simulated annealing as well as gradient ascent. Moreover, the faster construction of three-qubit Toffoli gates further confirmed the applicability of RS in larger registers.

The presence of the term $\left(v/c\right)$ that characterizes the electrodynamic retarded potentials, also known as Liénard–Wiechert potentials, is thought to be reminiscent of a Doppler effect. Here, we show that these potentials are consistent with the Doppler shifted electromagnetic (e.m.) field generated by a charge moving along a generic trajectory. Of course, the retarded potentials derived here are formally the same as those reported in the current literature. Nonetheless, this work sheds a new light on the origin of the electrodynamics retarded fields, offering a direct physical interpretation of the term $\left(v/c\right)$ characterizing the related potentials and making more evident the geometry underlying the radiation field associated to a moving charge. This could inspire new visions for calculating radiation and fields from accelerated charges, including particle physics, Cherenkov radiation and electromagnetic fields in curved space–time.

Radar absorbing structural (RAS) composites are laminate with a low reflection coefficient for the electromagnetic illumination in microwave frequency range, and thus it can be used in the civil and stealth applications. In this study, a series of Exfoliated Graphite (EG) in combination with U-type barium hexaferrite based epoxy composites was fabricated with varying weight percentages (0.25, 0.50, 0.75 and 1.00 wt%) of EG and fixed wt.% (60 wt%) of U-type hexaferrite through wet mixing and compression moulding technique. Here, Raman spectra shows the EG to be defect-free characteristics. Subsequently, prepared composites were measured for microstructure and electromagnetic (EM) properties in 8.2–12.4 GHz frequency range (X-band). Further, complex permittivity (ε_r = ε′−jε″) and complex permeability (μ_r = μ′−jμ″) of the designed composites were measured using Vector Network Analyzer (VNA). Designed EG/hexaferrite-epoxy composite shows maximum real permittivity and permeability values (ε′ = 18.90 and μ′ = 0.91) for 3.3 mm thickness with minimum reflection loss −8.43 dB with 0.75 wt % EG filled (Sample-3)in X-band. While, it can withstand the different mechanical forces and shown the better absorption mechanism.EG plays important role due to their unique properties with optimize loading percentages in ferrite-epoxy composites. It may be concluded that, optimized EG/hexaferrite based composites determine as good microwave absorber in 8.2–12.4 GHz frequency ranges. Consequently, the prepared structural composites can be used to design the microwave absorbers and electromagnetic interference (EMI) shields for stealth applications.