On the possibility of discrimination between $\pi^0, \eta, \omega, K^0_s$ mesons and a photon based on the calorimeter information in the CMS detector

TL;DR

This paper investigates the ability of the CMS calorimeter to distinguish between direct photons and background mesons like $ ho^0$, $ ho^ ext{0}$, $ ho^+$, and $K^0_s$, across different energies and pseudorapidity regions.

Contribution

It provides a detailed analysis of meson rejection factors using calorimeter data, considering various meson decay channels and energy ranges, enhancing photon identification techniques.

Findings

Rejection factors vary with meson type and energy.

Calorimeter information alone can achieve significant background suppression.

Performance depends on pseudorapidity regions and decay modes.

Abstract

The possibility of separating the $\pi^0, \eta, \omega$ and $K^0_s$ meson background from the signal photons produced directly in $pp$ collisions is analyzed. The rejection factors for two pseudorapidity regions 0.4<\eta<1.0$ and 1.6<\eta<2.0$ and six Et values, 20, 40, 60, 80, 100 and 200 GeV, are calculated for a case when only the calorimeter information is used. The cases of $\eta, \omega$ and $K^0_s$ mesons decaying through the neutral and charged channels are considered separately.