The MEG Spectrometer at PSI

TL;DR

The paper describes the design, implementation, and performance of the MEG spectrometer used in the 2008 physics run to search for the lepton flavor violating decay $ o e^+$, utilizing advanced detectors for precise measurements.

Contribution

It presents the detailed design and performance evaluation of the MEG spectrometer components used in the 2008 physics run.

Findings

High-resolution liquid xenon calorimeter achieved precise energy measurements.

Ultra-light drift chambers provided accurate momentum measurements.

Timing counter enabled precise positron timing detection.

Abstract

The MEG experiment is designed to search the Lepton Flavor Violating process $\mu \to e^+\gamma$ \cite{mori-1999,meg2007-baldini}. This search requires a high intensity muon beam stopping in a thin target with the maximum rate compatible with the background from combinatorial events. The events are analyzed by a high resolution and fast liquid xenon calorimeter and by a spectrometer composed by an array of ultra-light drift chambers (DCH) for momentum measurement and a double layered timing counter (TC) for measuring the $e^+$ time. The design parameters and performance of the spectrometer during the 2008 physics run are described.