Noncommutative magnetic moment, fundamental length and lepton size

TL;DR

The paper explores how noncommutative electrodynamics sets upper bounds on fundamental length scales through magnetic moment considerations, but these bounds are not yet tight enough to explain the muon magnetic moment discrepancy.

Contribution

It provides new upper bounds on fundamental length from noncommutative electrodynamics and discusses their implications for lepton size and magnetic moments.

Findings

Fundamental length bounds are larger than current estimates of electron and muon sizes.

Noncommutative electrodynamics alone cannot fully explain the muon magnetic moment discrepancy.

Future improvements in measurements could tighten bounds to match lepton compositeness scales.

Abstract

Upper bounds on fundamental length are discussed that follow from the fact that a magnetic moment is inherent in a charged particle in noncommutative (NC) electrodynamics. The strongest result thus obtained for the fundamental lenth is still larger than the estimate of electron or muon size achieved following the Brodsky-Drell and Dehlmet approach to lepton compositeness. This means that NC electrodynamics cannot alone explain the whole existing descrepancy between the theoretical and experimental values of the muon magnetic moment. On the contrary, as measurements and calculations are further improved, the fundamental length estimate based on electron data may go down to match its compositeness radius.