The PADME beam line Monte Carlo simulation

TL;DR

This paper presents a detailed Geant4-based Monte Carlo simulation of the PADME experiment's beam line, enabling accurate background prediction crucial for detecting invisible dark sector particles.

Contribution

It introduces a comprehensive simulation framework that models the entire beam line and detector, improving background understanding for the PADME experiment.

Findings

Enhanced background prediction accuracy

Full particle interaction modeling during transport and detection

Improved sensitivity for dark sector particle searches

Abstract

The PADME experiment at the DA$\Phi$NE Beam-Test Facility (BTF) of the INFN Laboratory of Frascati is designed to search for invisible decays of dark sector particles produced in electron-positron annihilation events with a positron beam and a thin fixed target, by measuring the missing mass of single-photon final states. The presence of backgrounds originating from beam halo particles can significantly reduce the sensitivity of the experiment. To thoroughly understand the origin of the beam background contribution, a detailed Geant4-based Monte Carlo simulation has been developed, containing a full description of the detector together with the beam line and its optical elements. This simulation allows the full interactions of each particle to be described, both during beam line transport and during detection, a possibility which represents an innovative way to obtain reliable background predictions