Über den magnetischen Formfaktor des Nukleons

1959 ◽  
Vol 14 (8) ◽  
pp. 699-707
Author(s):  
H. Eisenlohr ◽  
H. Salecker
Keyword(s):  
Perturbation Theory ◽  
Form Factor ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Form Factors ◽  
Sufficient Accuracy ◽  
Mean Square ◽  
Vector Form ◽  
High Q ◽  
Moment Distribution

This article deals with the form factor of the anomalous magnetic moment distribution of proton and neutron. It is first shown with three examples that the magnetic root mean square radius cannot be taken from the existing experiments with sufficient accuracy. Satisfactory agreement with the experimental results can be obtained with arbitrary values of rm2. We calculate the magnetic moment form factors depending on the energy momentum transfer q2 in perturbation theory and the 2 π meson contribution to the isotopic vector form factor with dispersion relations also in relation to q2, with and without π meson form factor. We get better agreement of the shape of the form factor with the phenomenological form factor of HOFSTADTER at the expense of the static magnetic moment. But the contribution of the high q2 values is still too large i.e. the structure is somewhat too concentrated **

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.

scholarly journals Dispersive analysis of light-meson transition form factors

2019 ◽  
Vol 218 ◽  
pp. 03001
Author(s):  
Bastian Kubis
Keyword(s):  
Light Scattering ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Form Factors ◽  
Experimental Information ◽  
Light Meson ◽  
Transition Form ◽  
Dispersive Analysis

We discuss status and prospects of a dispersive analysis of the π0, η, and η ′ transition form factors. Particular focus is put on the various pieces of experimental information that serve as input to such a calculation. These can help improve on the precision of an evaluation of the light pseudoscalar pole contributions to hadronic light-by-light scattering in the anomalous magnetic moment of the muon.**

scholarly journals Gamma-gamma physics and meson transition form factors

2020 ◽  
Vol 234 ◽  
pp. 01008
Author(s):  
Andrzej Kupsc
Keyword(s):  
Pseudoscalar Meson ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Neutral Pion ◽  
Form Factors ◽  
Photon Production ◽  
Transition Form ◽  
Muon Anomalous Magnetic Moment ◽  
Two Photon ◽  
Radiative Processes

I summarize recent experimental results for two photon production of mesons. These processes include the neutral pion, η and η′ transition form factors and two photon production of pseudoscalar meson pairs. In addition I discuss the related hadronic and radiative processes. All these processes are attracting attention of experiment and theory due their relevance for the hadronic light-by-light contribution to the muon anomalous magnetic moment.

scholarly journals Pion mass dependence of the HVP contribution to muon g – 2

2018 ◽  
Vol 175 ◽  
pp. 06010
Author(s):  
Maarten Golterman ◽  
Kim Maltman ◽  
Santiago Peris
Keyword(s):  
Perturbation Theory ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Pion Mass ◽  
Systematic Errors ◽  
Mass Dependence ◽  
Chiral Perturbation ◽  
Muon Anomalous Magnetic Moment ◽  
Chiral Extrapolation ◽  
Pion Mass Dependence

One of the systematic errors in some of the current lattice computations of the HVP contribution to the muon anomalous magnetic moment g – 2 is that associated with the extrapolation to the physical pion mass. We investigate this extrapolation assuming lattice pion masses in the range of 220 to 440 MeV with the help of two-loop chiral perturbation theory, and find that such an extrapolation is unlikely to lead to control of this systematic error at the 1% level. This remains true even if various proposed tricks to improve the chiral extrapolation are taken into account.

scholarly journals THE NUCLEON'S MIRROR IMAGE: REVEALING THE STRANGE AND UNEXPECTED

2003 ◽  
Vol 18 (02n06) ◽  
pp. 75-84 ◽  
Author(s):  
R. D. MCKEOWN
Keyword(s):  
Form Factor ◽  
Electron Scattering ◽  
Strange Quark ◽  
Form Factors ◽  
Mirror Image ◽  
Vector Form ◽  
Electromagnetic Structure ◽  
Extensive Program ◽  
Axial Form ◽  
Insight Into

An extensive program of parity-violating electron scattering experiments is providing new insight into the structure of the nucleon. Measurement of the vector form factors enables a definitive study of potential strange quark-antiquark contributions to the nucleon's electromagnetic structure, including the magnetic moment and charge distribution. Recent experimental results have already indicated that effects of strangeness are much smaller than theoretically expected. In addition, the neutral axial form factor appears to display substantial corrections as one might expect from an anapole effect.

Sign in / Sign up

Export Citation Format

Share Document