Measurements of $\pi^{\pm}$, $K^{\pm}$ and proton yields from the surface of the T2K replica target for incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS

TL;DR

This paper reports precise measurements of pion, kaon, and proton yields from a T2K replica target using the NA61/SHINE spectrometer, aiming to improve neutrino flux predictions for the T2K experiment.

Contribution

First-time measurements of $K^{ ext{±}}$ and proton yields from the T2K replica target, with improved pion yield precision and a new method to handle beam profile dependence.

Findings

Enhanced precision in $ ext{π}^{ ext{±}}$ yield measurements.

First measurements of $K^{ ext{±}}$ and proton yields from the target surface.

A strategy to account for incoming beam profile effects.

Abstract

Measurements of the $\pi^{\pm}$, $K^{\pm}$, and proton double differential yields emitted from the surface of the 90-cm-long carbon target (T2K replica) were performed for the incoming 31 GeV/c protons with the NA61/SHINE spectrometer at the CERN SPS using data collected during 2010 run. The double differential $\pi^{\pm}$ yields were measured with increased precision compared to the previously published NA61/SHINE results, while the $K^{\pm}$ and proton yields were obtained for the first time. A strategy for dealing with the dependence of the results on the incoming proton beam profile is proposed. The purpose of these measurements is to reduce significantly the (anti)neutrino flux uncertainty in the T2K long-baseline neutrino experiment by constraining the production of (anti)neutrino ancestors coming from the T2K target.