Study of the Neutral-Current interactions with production of neutral pions in the T2K off-axis near detector

TL;DR

This paper analyzes neutral-current neutrino interactions producing neutral pions in the T2K near detector to improve background understanding for electron neutrino appearance measurements.

Contribution

It presents a new selection method and fitting approach to measure the inclusive NC${ m oldsymbol{ ext{ extpi}}^0}$ interaction rate in T2K data, enhancing background modeling.

Findings

Improved selection criteria for NC${ m oldsymbol{ ext{ extpi}}^0}$ interactions.

Use of a fitting method to refine interaction rate measurement.

Comparison of data with different neutrino interaction models.

Abstract

This analysis aims to study inclusive neutrino-induced Neutral Current (NC) interactions that produce at least one neutral pion (${\pi}^0$) in the final state (incNC${\pi}^0$ ) in the T2K off-axis near detector ND280. The motivation for this study is to better understand/eliminate the background to electron neutrino appearance analyzed at the far detector Super-Kamiokande. As ${\pi}^0$ decays are background to the appearance search, a good knowledge of both inclusive and exclusive neutrino interaction cross sections are key to improving associated systematic uncertainties in T2K oscillation analyses. Results from this study can be compared to a number of Monte Carlo samples produced using different neutrino interaction generators. This could yield information about models of neutrino-nucleon interactions. Further comparisons can be made with the incCC${\pi}^0$ sample already obtained from a T2K near detector analysis. In this poster, the selection criteria used to collect inclusive neutral current neutrino interactions on plastic scintillator (CH) with at least one ${\pi}^0$ in the final state will be presented, including a discussion of how selection criteria were improved. I will also discuss the changes in the selections, including use of a fitting method to improve measurement of the incNC${\pi}^0$ interaction rate.