Probing ALPs at the CERN Gamma Factory

TL;DR

This paper explores the CERN Gamma Factory's potential to detect axion-like particles (ALPs) by leveraging its high photon flux, proposing various production and detection methods to extend the search for new physics beyond the Standard Model.

Contribution

It introduces the use of the CERN Gamma Factory for ALP searches, analyzing different production scenarios and demonstrating improved sensitivity over previous experiments.

Findings

Gamma Factory can probe ALPs with masses up to ~100 MeV.

It can detect ALPs with decay constants >10^7 GeV.

Enhanced discovery potential compared to past beam dump experiments.

Abstract

The aim of the proposed CERN Gamma Factory is to produce $\sim 10^{17}$ photons per second with energies up to 400 MeV. The photon beam intensity is expected to be a factor of $\mathcal{O}(10^7)$ larger than that of the presently available photon beams in the MeV energy range. In this work, we explore its potential to probe physics beyond the Standard Model. In particular, we discuss searches for axion like particles (ALPs) with dominant couplings to photons and consider various production scenarios - fixed target, photon-photon collision, and conversion by a magnetic field and detection schemes - via decay to photons or back-conversion. We find that the Gamma Factory in a fixed target mode can probe ALPs with mass $m_a \lesssim \mathcal{O}(100\,\mathrm{MeV})$ and decay constants larger than $10^7$ GeV, improving by an order of magnitude the discovery potential of previous beam dump experiments.