Highly Accurate Derivation of the Electron Magnetic Moment Anomaly From Spherical Geometry Using a Single Evaluation

The electron magnetic moment anomaly (ae), is normally derived from the fine structure constant using an intricate method requiring over 13,500 evaluations, which is accurate to 11dp. This paper advances the derivation using the fine structure constant and a spherical geometric model for the charge of the electron to reformulate the equation for ae. This highly accurate derivation is also based on the natural log eπ, and the zero-order spherical Bessel function. This determines a value for the electron magnetic moment anomaly accurate to 13 decimal places, which gives a result which is 2 orders of magnitude greater in accuracy than the conventional derivation. Thus, this derivation supersedes the accuracy of the conventional derivation using only a single evaluation.

Stochastic Electron Acceleration by Temperature Anisotropy Instabilities under Solar Flare Plasma Conditions

Using 2D particle-in-cell plasma simulations, we study electron acceleration by temperature anisotropy instabilities, assuming conditions typical of above-the-loop-top sources in solar flares. We focus on the long-term effect of T e,⊥ > T e,∥ instabilities by driving the anisotropy growth during the entire simulation time through imposing a shearing or a compressing plasma velocity (T e,⊥ and T e,∥ are the temperatures perpendicular and parallel to the magnetic field). This magnetic growth makes T e,⊥/T e,∥ grow due to electron magnetic moment conservation, and amplifies the ratio ω ce/ω pe from ∼0.53 to ∼2 (ω ce and ω pe are the electron cyclotron and plasma frequencies, respectively). In the regime ω ce/ω pe ≲ 1.2–1.7, the instability is dominated by oblique, quasi-electrostatic modes, and the acceleration is inefficient. When ω ce/ω pe has grown to ω ce/ω pe ≳ 1.2–1.7, electrons are efficiently accelerated by the inelastic scattering provided by unstable parallel, electromagnetic z modes. After ω ce/ω pe reaches ∼2, the electron energy spectra show nonthermal tails that differ between the shearing and compressing cases. In the shearing case, the tail resembles a power law of index α s ∼ 2.9 plus a high-energy bump reaching ∼300 keV. In the compressing runs, α s ∼ 3.7 with a spectral break above ∼500 keV. This difference can be explained by the different temperature evolutions in these two types of simulations, suggesting that a critical role is played by the type of anisotropy driving, ω ce/ω pe, and the electron temperature in the efficiency of the acceleration.

Natural geometric unit system and electron magnetic moment anomaly

Consequences of implementation of the natural geometric unit system (the SG) based on the pre-2019 SI system, in which four fundamental physical constants undergo joint numerical and dimensional normalization to unity c = G= k = h = 1, with only one base geometric unit u equal to √|h · G/c 3 | m, where the Newtonian gravitational constant G ≈ 6.673 655 205 · 10 -11 m3/(kg · s 2 ), are further explored. In addition to the earlier hypothesized simple electron mass to charge ratio formula me = e/(2 9πα), and formulas for stable quarks rest masses: quark u mu = √(⅔) / (2 7π √(πα)) u, equivalent of 2.360 MeV/c 2 and quark d md = √(⅓) -1 / (2 7π √(πα)) u, equivalent of 5.007 MeV/c 2 , a simple formula for electron magnetic moment anomaly is proposed α/2π - (α/2π) 2 - 2 8 (α/2π) 3 - 2 12 (α/2π) 4 - 2 16 (α/2π) 5 - 2 24 (α/2π) 6 ≈ 0.001 159 652 180. The finding supports the research area of purely geometric modelling of the fundamental physical forces and their unification. It seems plausible, that in the SG, with use of half integer powers of 2, 3, π and α only,all the fundamental properties of stable matter and electromagnetic radiation could be described

Invisible decays of axion-like particles: constraints and prospects

Axion-like particles (ALPs) can provide a portal to new states of a dark sector. We study the phenomenology of this portal when the ALP mainly decays invisibly, while its interaction with the standard model sector proceeds essentially via its coupling to electrons and/or photons. We reanalyse existing limits from various collider and beam dump experiments, including in particular ALP production via electron/positron interactions, in addition to the usual production through ALP-photon coupling. We further discuss the interplay between these limits and the intriguing possibility of explaining simultaneously the muon and electron magnetic moment anomalies. Finally, we illustrate the prospects of ALP searches at the LNF positron fixed-target experiment PADME, and the future reach of an upgraded experimental setup.

Supersymmetric gauged $$ \mathrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$ model for electron and muon (g − 2) anomaly

Minimal gauged $$ \mathrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$ U 1 L μ − L τ models can provide for an additional source for the muon anomalous magnetic moment however it is difficult to accommodate the discrepancy in the electron magnetic moment in tandem. Owing to the relative sign between the discrepancies in these quantities, it seems unlikely that they arise from the same source. We show that a supersymmetric (SUSY) gauged $$ \mathrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} $$ U 1 L μ − L τ model can accommodate both the muon and electron anomalous magnetic moments in a very simple and intuitive scenario, without utilizing lepton flavor violation. The currently allowed parameter space in this kind of a scenario is constrained from the latest LHC and various low energy experimental data,e.g., recent COHERENT data, CCFR, Borexino, BaBaR, supernova etc. These constraints, in conjunction with the requirement to explain both lepton magnetic moments, lead to an upper bound on the first generation slepton mass, a lower bound on the second generation slepton mass and constricts the allowed range for the new gauge boson mass and coupling. The scheme can be probed at the ongoing COHERENT and Coherent CAPTAIN-Mills experiments and at future experiments, e.g., DUNE, BELLE-II etc.

Natural geometric unit system and electron magnetic moment anomaly

Consequences of implementation of the natural geometric unit system (the SG) based on the pre-2019 SI system, in which four fundamental physical constants undergo joint numerical and dimensional normalization to unity c = G = k = h = 1, with only one base geometric unit u equal to √|h · G/c3| m, where the Newtonian gravitational constant G ≈ 6.673 655 205 · 10-11 m3/(kg · s2), are further explored. In addition to the earlier hypothesized simple electron mass to charge ratio formula me = e/(29πα), and formulas for stable quarks rest masses: quark u mu = √(⅔) / (27π √(πα)) u, equivalent of 2.360 MeV/c2 and quark d md = √(⅓)-1 / (27π √(πα)) u, equivalent of 5.007 MeV/c2, a simple formula for electron magnetic moment anomaly is proposed α/2π - (α/2π)2 - 28(α/2π)3 - 212(α/2π)4 - 216(α/2π)5 - 224(α/2π)6 ≈ 0.001 159 652 180. The finding supports the research area of purely geometric modelling of the fundamental physical forces and their unification. It seems plausible, that in the SG, with use of half integer powers of 2, 3, π and α only, all the fundamental properties of stable matter and electromagnetic radiation could be described.

Implications of last NA64 results and the electron ge − 2 anomaly for the X(16.7) boson survival

We point out that last NA64 bound on coupling constant of hypothetical X[Formula: see text](16.7 MeV) vector boson with electrons plus the recent value of the anomalous electron magnetic moment exclude at 90% C.L. purely vector or axial–vector couplings of X[Formula: see text](16.7) boson with electrons. Models with nonzero [Formula: see text] coupling constant with electron survive and they can explain both the electron and muon [Formula: see text] anomalies.

Solution of the κ-Deformed Dirac Equation with Vector and Scalar Interactions in the Context of Spin and Pseudospin Symmetries

The deformed Dirac equation invariant under the κ-Poincaré-Hopf quantum algebra in the context of minimal and scalar couplings under spin and pseudospin symmetry limits is considered. The κ-deformed Pauli-Dirac Hamiltonian allows us to study effects of quantum deformation in a class of physical systems, such as a Zeeman-like effect, Aharonov-Bohm effect, and an anomalous-like contribution to the electron magnetic moment, between others. In our analysis, we consider the motion of an electron in a uniform magnetic field and interacting with (i) a planar harmonic oscillator and (ii) a linear potential. We verify that the particular choice of a linear potential induces a Coulomb-type term in the equation of motion. Expressions for the energy eigenvalues and wave functions are determined taking into account both symmetry limits. We verify that the energies and wave functions of the particle are modified by the deformation parameter as well as by the element of spin.

Estimating the radiative part of QED effects in systems with supercritical charge

The effective interaction of the electron magnetic moment anomaly with the Coulomb fileld of superheavy nuclei is investigated by taking into account its dynamical screening at small distances. The shift of the electronic levels, caused by this interaction, is considered for H-like atoms and for compact nuclear quasi-molecules, non-perturbatively both in Zα and (partially) in α/π. It is shown that the levels shift reveals a non-monotonic behavior in the region Zα 1 and near the threshold of the lower continuum decreases both with the increasing the charge and with enlarging the size of the system of Coulomb sources. The last result is generalized to the total self-energy contribution to the levels shift and so to the possible behavior of radiative QED effects with virtual photon exchange near the lower continuum in the supercritical region.