Extracting longitudinal shower development information from crystal calorimetry plus tracking

TL;DR

This paper introduces a method to extract longitudinal shower development data from unsegmented crystal calorimetry using tracking information, enhancing particle identification in the BABAR detector.

Contribution

The novel algorithm leverages BABAR's tracking resolution to infer longitudinal shower details, improving low-momentum particle separation and validating electromagnetic shower models.

Findings

Improved pion-electron-muon separation at low momentum.

Consistent electromagnetic shower development with standard models.

Enhanced particle identification accuracy.

Abstract

We propose an approach to derive longitudinal shower development information from the longitudinally unsegmented BABAR electromagnetic calorimeter by using tracking information. Our algorithm takes advantage of the good three-dimensional tracking resolution of BABAR, which provides an independent geometric constraint on the shower as measured in the BABAR crystal calorimeter. We show that adding the derived longitudinal shower development information to standard particle identification algorithms significantly improves the low-momentum separation of pions from electrons and muons. We also verify that the energy dependence of the electromagnetic shower development we measure is consistent with the prediction of a standard electromagnetic shower model.