# Hadron energy estimation from Atmospheric neutrino events

## TL;DR

This paper investigates how to estimate hadron energy in atmospheric neutrino events at ICAL by analyzing hadron hits, revealing the dominance of baryons at energies below 5 GeV, and proposing a new estimation method.

## Contribution

It introduces a novel approach to estimate hadron energy from detector hits, enhancing neutrino oscillation analysis capabilities.

## Key findings

- Most hadron energy below 5 GeV is carried by baryons.
- A correlation between hadron hits and hadron energy is established.
- A procedure for hadron energy estimation from hits is formulated.

## Abstract

The ICAL at INO is designed to mainly observe the muons produced in the charged current interactions of atmospheric muon neutrinos and anti-neutrinos. The track of the muon is reconstructed using the hits they produce in the detector. From this track, the charge, the energy and the direction of the muon are estimated, which are used to do oscillation physics analysis. In a large fraction of events, a number of hadrons are also produced in addition to the muons. The charged hadrons also leave hits in the detector which can be utilized to estimate the hadron energy. In this work, we study the relation between hadron hits, defined to be the difference between the total number of hits and the muon track hits, and the hadron energy. We find that a non-negligible number of baryons are produced in atmospheric neutrino interactions. For E(had) < 5 GeV, almost all the hadron energy is carried by these baryons. Finally, we formulate a procedure by which the hadron energy can be estimated from the number of hadron hits.