# Photon reconstruction using the Hough transform in imaging calorimeters

## TL;DR

This paper introduces a novel photon reconstruction method using the Hough transform focused on energy-core structures in calorimeters, significantly improving efficiency in high-density particle physics environments.

## Contribution

The paper extends the Hough transform application to energy-core structures for photon reconstruction, demonstrating near-perfect efficiency in simulations.

## Key findings

- Reconstruction efficiency exceeds 99% for photons >2 GeV
- Separation efficiency approaches 100% for two 5 GeV photons at calorimeter granularity limit
- Method enhances photon measurement in complex, high-multiplicity events

## Abstract

Photon reconstruction in calorimeters represents a crucial challenge in particle physics experiments, especially in high-density environments where shower overlapping probabilities become significant. We present an energy-core-based photon reconstruction method. It is achieved through extending the application of the Hough transform to exploit the energy-core structure of photon showers. The method, validated through simulations of the CEPC crystal electromagnetic calorimeter, achieves a reconstruction efficiency of nearly 100% for photons with energies exceeding 2 GeV and a separation efficiency approaching 100% for two 5 GeV photons, when the distance between them reaches the granularity limit of the calorimeter. This energy-core-based photon reconstruction method, integrated with an energy splitting technique, enhances the performance of photon measurement and provides a promising tool for imaging calorimeters, particularly those requiring high precision in photon detection in complex event topologies with high multiplicity.