Underground Production of Electromagnetic Dark States by MeV-scale Electron Beams and Detection with CCDs

TL;DR

This paper investigates the underground production and detection of hypothetical light fermionic particles with millicharge or electromagnetic form factors using MeV-scale electron beams and CCD sensors, aiming to explore new physics beyond current constraints.

Contribution

It analytically evaluates production mechanisms and cross sections for millicharged fermions and dipole moments, proposing a novel experimental setup for probing untested parameter space.

Findings

Potential to probe unconstrained millicharged fermions with electron beams.

Feasibility of detecting fermion dipole moments with increased beam energy or time.

Analytical and numerical calculation of production cross sections.

Abstract

In this work we explore the possibility of new light fermionic particles with millicharge or electromagnetic form factor interactions and their underground production via an electron beam in the 100 MeV range and their subsequent detection using a CCD-sensor. We evaluate the S-matrix elements and the phase spaces for production analytically, and then calculate the corresponding cross sections numerically. For millicharged fermions this set-up could be able to probe a window in parameter space, yet unconstrained by direct detection experiments. The electric or magnetic dipole moment of a light fermion could feasibly be probed with enough beam time or an increased beam energy.