Feasibility of Low-Energy True Muonium Photoproduction

TL;DR

This study assesses the feasibility of producing true muonium, a bound state of muons, using low-energy photoproduction at CERN's Gamma Factory, highlighting potential for experimental observation and physics measurements.

Contribution

It demonstrates that the Gamma Factory could generate sufficient photon flux for true muonium production and outlines strategies to detect and study this exotic atom.

Findings

Gamma Factory can provide the necessary photon energies and rates.

Cut-based selection methods can suppress background signals.

Feasibility of observing true muonium at CERN is supported.

Abstract

True muonium, the bound state of a muon and an antimuon, is a theoretically well-understood but experimentally unobserved exotic atom. Its purely leptonic nature makes it a sensitive probe for bound-state quantum electrodynamics and possible physics beyond the Standard Model. We present a feasibility study of low-energy true muonium production via near-threshold photoproduction on a fixed target. The study includes simulations of the signal and dominant background processes, estimates of the required photon fluxes, and an overview of possible gamma sources. We show that the proposed Gamma Factory at CERN could provide the necessary photon energies and rates for the production of true muonium. Furthermore, cut-based selections are shown to suppress the background below the expected signal level. Finally, we discuss possible physics opportunities beyond the first observation, including measurements of its lifetime, hyperfine splitting, and Lamb shift.