Muon magnetic anomaly: experimental status and prospects

TL;DR

This paper reviews recent experimental and theoretical developments in the muon magnetic anomaly, highlighting tensions between measurements and the Standard Model, and discusses future prospects including the MUonE experiment at CERN.

Contribution

It provides a comprehensive overview of the current status and future prospects for understanding the muon g-2 anomaly, emphasizing the potential of the MUonE experiment.

Findings

Significant tension between experimental and SM values of a_mu.

Discrepancies between lattice QCD calculations and experimental results.

Potential for new measurements to resolve existing uncertainties.

Abstract

The past five years have brought significant new results on the muon magnetic anomaly, $a_\mu = (g_\mu - 2)/2$, and on the hadronic vacuum polarization (HVP) contribution dominating the uncertainty $\Delta a_\mu$. Serious tension has emerged between the experimental and standard model(SM) values for $a_\mu$, as well as between the SM and the first precise lattice QCD values. We review the current experimental and theoretical status of $a_\mu$, along with the prospects for new results,focusing on MUonE,a new experiment at CERN, aiming to evaluate the leading order contribution to a(HVP) in a direct measurement of muonic Bhabha scattering.