Electromagnetic Shower Properties in a Lead-Scintillator Sampling Calorimeter

TL;DR

This paper presents a detailed Geant4 simulation and parameterization of electromagnetic shower responses in the CDF electromagnetic calorimeter, aiding precise measurements like the W boson mass.

Contribution

It provides a detailed Geant4-based model and parameterization of the CDF electromagnetic calorimeter response to electrons and photons, improving simulation accuracy.

Findings

Accurate modeling of energy leakage and sampling fractions.

Parameterization of energy response and resolution.

Enhanced simulation for W boson mass measurement.

Abstract

The Collider Detector at Fermilab (CDF) is a general-purpose experimental apparatus with an inner tracking detector for measuring charged particles, surrounded by a calorimeter for measurements of electromagnetic and hadronic showers. We describe a {\sc geant4} simulation and parameterization of the response of the CDF central electromagnetic calorimeter (CEM) to incident electrons and photons. The detector model consists of a detailed description of the CEM geometry and material in the direction of the incident particle's trajectory, and of the passive material between the tracker and the CEM. We use {\sc geant4} to calculate the distributions of: the energy that leaks from the back of the CEM, the energy fraction sampled by the scintillators, and the energy dependence of the response. We parameterize these distributions to accurately model electron and photon response and resolution in a custom simulation for the measurement of the $W$ boson mass.