Bound states, resonances, and symmetries of a neutral Dirac particle with anomalous magnetic moment, coupled to a fixed monopole

1985 ◽  
Vol 26 (6) ◽  
pp. 1390-1396 ◽  
Author(s):  
A. O. Barut ◽  
A. J. Bracken
Keyword(s):  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Bound States ◽  
Dirac Particle

scholarly journals Quantum states of a neutral massive fermion with an anomalous magnetic moment in an Aharonov–Casher field

2017 ◽  
Vol 32 (18) ◽  
pp. 1750111
Author(s):  
V. R. Khalilov
Keyword(s):  
Cross Sections ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Quantum Dynamics ◽  
Bound States ◽  
Scattering Amplitude ◽  
Energy Levels ◽  
Initial State ◽  
Massive Fermion ◽  
A Charge

The planar nonrelativistic quantum dynamics of a neutral massive fermion with an anomalous magnetic moment (AMM) in the electric field of infinitely long and thin thread with a charge density distributed uniformly along it (an Aharonov–Casher field) is examined. The relevant Hamiltonian is singular and requires additional specification of a one-parameter self-adjoint extension, which can be given in terms of physically acceptable boundary conditions. We find all possible self-adjoint Hamiltonians with an Aharonov–Casher field (ACF) by constructing the corresponding Hilbert space of square-integrable functions, including the [Formula: see text] region, for all their Hamiltonians. We determine the most relevant physical quantities, such as energy spectrum and wave functions and discuss their correspondence with those obtained by the physical regularization procedure. We show that energy levels of bound states are simple poles of the scattering amplitude. It is shown that the scattering amplitudes and cross-sections depend essentially on the initial-state spin of fermions.

scholarly journals Two and three pseudoscalar production in e+e− annihilation and their contributions to (g − 2)μ

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Wen Qin ◽  
Ling-Yun Dai ◽  
Jorge Portolés
Keyword(s):  
Experimental Data ◽  
Theoretical Prediction ◽  
Pseudoscalar Meson ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Vacuum Polarization ◽  
Meson Production ◽  
The Other ◽  
Joint Analysis ◽  
The Standard Model

Abstract A coherent study of e+e− annihilation into two (π+π−, K+K−) and three (π+π−π0, π+π−η) pseudoscalar meson production is carried out within the framework of resonance chiral theory in energy region E ≲ 2 GeV. The work of [L.Y. Dai, J. Portolés, and O. Shekhovtsova, Phys. Rev. D88 (2013) 056001] is revisited with the latest experimental data and a joint analysis of two pseudoscalar meson production. Hence, we evaluate the lowest order hadronic vacuum polarization contributions of those two and three pseudoscalar processes to the anomalous magnetic moment of the muon. We also estimate some higher-order additions led by the same hadronic vacuum polarization. Combined with the other contributions from the standard model, the theoretical prediction differs still by (21.6 ± 7.4) × 10−10 (2.9σ) from the experimental value.

scholarly journals Stochastic computation of g − 2 in QED

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Ryuichiro Kitano ◽  
Hiromasa Takaura ◽  
Shoji Hashimoto
Keyword(s):  
Perturbation Theory ◽  
Numerical Computation ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Stochastic Perturbation ◽  
Higher Order ◽  
Feynman Diagrams ◽  
Perturbative Series ◽  
Physical Quantities

Abstract We perform a numerical computation of the anomalous magnetic moment (g − 2) of the electron in QED by using the stochastic perturbation theory. Formulating QED on the lattice, we develop a method to calculate the coefficients of the perturbative series of g − 2 without the use of the Feynman diagrams. We demonstrate the feasibility of the method by performing a computation up to the α3 order and compare with the known results. This program provides us with a totally independent check of the results obtained by the Feynman diagrams and will be useful for the estimations of not-yet-calculated higher order values. This work provides an example of the application of the numerical stochastic perturbation theory to physical quantities, for which the external states have to be taken on-shell.

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