Pulse Shape Particle Identification by a Single Large Hemispherical Photo-Multiplier Tube

TL;DR

This paper demonstrates that pulse shape analysis with a single large hemispherical PMT can distinguish between different particle types at low energies, offering a new method for particle identification in neutrino detectors.

Contribution

It introduces a pulse shape PID technique using a single hemispherical PMT, enabling particle discrimination with minimal hit information in neutrino experiments.

Findings

Pulse shape PID can distinguish 2 GeV electrons from 8 GeV pions.

Statistical separation achieved with ~20 PE charge deposition.

Applicable to future low-energy neutrino telescopes like IceCube-Upgrade.

Abstract

In neutrino experiments, hemispherical photomultiplier tubes (PMTs) are often used to cover large surfaces or volumes to maximize the photocathode coverage with a minimum number of channels. Instrumentation is often coarse, and neutrino event reconstruction and particle identification (PID) is usually done through the morphology of PMT hits. In future neutrino experiments, it may be desirable to perform PID from a few hits, or even a single hit, by utilizing pulse shape information. In this report, we study the principle of pulse shape PID using a single 10-inch hemispherical PMT in a spherical glass housing for future neutrino telescopes. We use the Fermilab Test Beam Facility (FTBF) MTest beamline to demonstrate that with pulse shape PID, statistical separation is possible to distinguish 2 GeV electrons from 8 GeV pions, where the total charge deposition is ~20 PE in our setup. Such techniques can be applied to future neutrino telescopes focusing on low energy physics, including the IceCube-Upgrade.