# The 16th International Workshop on Tau Lepton Physics (TAU2021) (Virtual Edition)

September 27, 2021 to October 1, 2021
Indiana University
America/Indiana/Indianapolis timezone

## Perturbative heavy quark contributions to the anomalous magnetic moment of the muon

Sep 30, 2021, 2:55 PM
20m
Virtual (Indiana University)

### Virtual

#### Indiana University

Oral contribution Tau2021 Abstracts

### Speaker

Philip David Kennedy (Johannes Gutenberg Universitaet Mainz (DE))

### Description

We discuss a method for calculating the heavy quark vacuum polarisation contribution to the muon anomalous magnetic moment, $a_\mu$, using perturbative QCD up to ${\cal O}\left(\alpha_s^3\right)$. This approach is independent of $e^+e^-$ cross-section data allowing a fully theoretical evaluation of these contributions. This method confirms an existing result at lower orders in $\alpha_s$ and we state a new explicit analytic formula which includes terms up to ${\cal O}\left(\alpha_s^3\right)$. Numerically the charm quark contribution to $a_\mu$ is found to be $a_\mu^c = (14.5 \pm 0.2)\times 10^{-10}$ and the bottom contribution is $a_\mu^b = (0.302 \pm 0.002) \times 10^{-10}$. Our uncertainty estimates include both parametric uncertainties, arising from $\hat{m}_q(\hat{m}_q)$ and $\alpha_s(\hat{m}_q)$, and theoretical uncertainties in the perturbative expansion. Comparison is then made between these results and those from alternative approaches such as, lattice QCD, or based on a dispersion relation and cross-section data.

What is your topic? Anomalous Magnetic Moment of the muon

### Primary authors

Hubert Spiesberger (Mainz University) Philip David Kennedy (Johannes Gutenberg Universitaet Mainz (DE))