Dispersive approaches for the HVP and HLbL contributions to $(g-2)_\mu$

TL;DR

This paper reviews dispersive methods for calculating the hadronic contributions to the muon's anomalous magnetic moment, focusing on analytic constraints, radiative corrections, and isospin-breaking effects to improve theoretical precision.

Contribution

It introduces recent dispersive approaches that leverage analytic properties to better constrain hadronic effects in $(g-2)_4$ calculations.

Findings

Dispersive methods effectively constrain HVP and HLbL contributions.

Analyticity constraints improve the accuracy of hadronic cross section estimates.

Inclusion of radiative corrections and isospin-breaking effects refines the theoretical predictions.

Abstract

Calculations based on the analytic properties of the required matrix elements allow for a wide range of applications constraining the hadronic contributions to the anomalous magnetic moment of the muon $a_\mu=(g-2)_\mu/2$, both hadronic vacuum polarization (HVP) and hadronic light-by-light (HLbL) scattering. Here, we discuss such recent applications, including analyticity constraints on hadronic cross sections, radiative corrections, and isospin-breaking effects.