# Studies of granularity of a hadronic calorimeter for tens-of-TeV jets at a 100 TeV $pp$ collider

## TL;DR

This study investigates how the granularity of a hadronic calorimeter affects jet substructure reconstruction for high-energy jets at a 100 TeV collider, showing smaller cells improve performance.

## Contribution

It provides a detailed simulation-based analysis of calorimeter cell size impact on jet substructure at very high energies, guiding detector design for future colliders.

## Key findings

- Smaller calorimeter cells significantly enhance jet substructure resolution.
- Performance improves when reducing cell size from 0.087×0.087 to 0.022×0.022.
- Results support finer granularity for better jet analysis at 100 TeV.

## Abstract

Jet substructure variables for hadronic jets with transverse momenta in the range from 2.5 TeV to 20 TeV were studied using several designs for the spatial size of calorimeter cells. The studies used the full Geant4 simulation of calorimeter response combined with realistic reconstruction of calorimeter clusters. In most cases, the results indicate that the performance of jet-substructure reconstruction improves with reducing cell size of a hadronic calorimeter from $\Delta \eta \times \Delta \phi = 0.087\times0.087$, which are similar to the cell sizes of the calorimeters of LHC experiments, by a factor of four, to $0.022\times0.022$.