Measuring Electron Energy in Muon-to-Electron Conversion using Holographic Synchrotron Radiation Emission Spectroscopy

TL;DR

This paper proposes a novel holographic track reconstruction method using synchrotron radiation to improve electron energy measurement in muon-to-electron conversion experiments, potentially overcoming detector limitations.

Contribution

It introduces a holographic detection technique based on synchrotron radiation emission for enhanced electron energy resolution in muon-to-electron conversion studies.

Findings

Conceptual feasibility of holographic tracker demonstrated

Potential for improved energy resolution over traditional detectors

Addresses limitations of electron scattering and energy loss

Abstract

The coherent conversion of a muon to an electron in a nuclear field has been one of the most powerful methods for searching for charged lepton flavor violation. Recent advancements have significantly enhanced the sensitivity of $\mu \rightarrow e$ searches, primarily driven by advancements in muon beamline design and low-mass tracking detectors, which afford exceptional momentum resolution. Nevertheless, the performance of these detectors is inherently limited by electron scattering and energy loss within detector materials. We propose a {\em holographic} track reconstruction method that leverages synchrotron radiation emitted by electrons to overcome these inevitable limitations. Similar to cyclotron radiation emission spectroscopy, which has demonstrated outstanding energy resolutions for low-energy electrons, our technique relies on a precision measurement of cyclotron frequency, but in a regime where photons are emitted stochastically and are projected onto a 2-dimensional inner surface of a solenoidal magnet. We outline the concept of such a massless holographic tracker and the feasibility of employing this innovative detection strategy for $\mu \rightarrow e$ conversion. We also address pertinent limitations and challenges inherent to the method.