Challenges of Particle Flow reconstruction in the CMS High-Granularity Calorimeter at the High-Luminosity LHC

Frank Chlebana

doi:10.1088/1742-6596/928/1/012027

Abstract

The challenges of the High-Luminosity LHC (HL-LHC) are driven by the large number of overlapping proton-proton collisions (pileup) in each bunch-crossing and the extreme radiation dose to detectors at high pseudorapidity. To overcome this challenge CMS is developing an endcap electromagnetic+hadronic sampling calorimeter employing silicon sensors in the electromagnetic and front hadronic sections, comprising over 6 million channels, and highly-segmented plastic scintillators in the rear part of the hadronic section. This High- Granularity Calorimeter (HGCAL) will be the first of its kind used in a colliding beam experiment. Clustering deposits of energy over many cells and layers is a complex and challenging computational task, particularly in the high-pileup environment of HL-LHC. Baseline detector performance results are presented for electromagnetic and hadronic objects, and studies demonstrating the advantages of fine longitudinal and transverse segmentation are explored.

Highlights

The Large Hadron Collider (LHC) is exptected to be upgraded to the High Luminosity LHC (HL-LHC) starting in 2024, resulting in an average of 140-200 interactions per crossing, and is projected to deliver an integrated luminosity of 3000 fb−1 over a ten year running period
The highly granular sampling calorimeter (HGCal) consists of a electromagnetic section (EE) of 28 sampling layers of silicon, followed by the front hadronic section (FH) consisting of 12 sampling layers of silicon, and the back hadronic section (BH) consisting of 12 sampling layers of scintillator
Summary The preliminary studies for the Compact Muon Solinoid (CMS) phase 2 technical proposal indicate that the HGCal will be able to maintain the necessary physics performance in the high pileup environment of the HLLHC

Summary

Introduction

The Large Hadron Collider (LHC) is exptected to be upgraded to the High Luminosity LHC (HL-LHC) starting in 2024, resulting in an average of 140-200 interactions per crossing (pileup), and is projected to deliver an integrated luminosity of 3000 fb−1 over a ten year running period. Challenges of Particle Flow reconstruction in the CMS High-Granularity Calorimeter at the Clustering deposits of energy over many cells and layers is a complex and challenging computational task, in the high-pileup environment of HL-LHC.

Results

Conclusion