Noncommutative magnetic moment of charged particles

TL;DR

This paper explores how noncommutative geometry affects the magnetic moments of charged particles, revealing that extended charges behave as magnetic dipoles and setting bounds on noncommutativity parameters.

Contribution

It extends noncommutative U(1)_*-theory to include external sources, showing charges acquire magnetic dipole moments, and derives experimental bounds on noncommutativity.

Findings

Charged particles exhibit magnetic dipole moments due to noncommutativity.

The noncommutativity scale is constrained to be above 10^4 TeV.

Extended charges cannot be smaller than an elementary length related to noncommutativity.

Abstract

It has been argued, that in noncommutative field theories sizes of physical objects cannot be taken smaller than an elementary length related to noncommutativity parameters. By gauge-covariantly extending field equations of noncommutative U(1)_*-theory to the presence of external sources, we find electric and magnetic fields produces by an extended charge. We find that such a charge, apart from being an ordinary electric monopole, is also a magnetic dipole. By writing off the existing experimental clearance in the value of the lepton magnetic moments for the present effect, we get the bound on noncommutativity at the level of 10^4 TeV.