Separation of \gamma/\pi^0 showers at high energies

TL;DR

This study introduces a two-layer Shower Maximum Detector diagonally offset (SMD-dos) that significantly improves the separation of b0/b0^0 showers at high energies, enhancing particle identification in collider experiments.

Contribution

The paper presents the design and simulation results of a novel SMD-dos that outperforms conventional detectors in b0/b0^0 separation efficiency at energies 30-150 GeV.

Findings

SMD-dos achieves b0 rejection efficiencies of 92b1 4%, 87b1 4%, and 32b1 2% at 30, 50, and 150 GeV.

SMD-dos is approximately 1.5 times more effective than conventional single-layer or multi-layer detectors.

Adding SMD-dos to LHC detectors could significantly reduce background in b3b3 decay detection.

Abstract

We have designed and carried out simulation studies of a two layer Shower Maximum Detector diagonally off-set (SMD-dos) optimized for the separation of \pi^0 showers from \gamma showers in the 30 to 150 GeV energy range. For 90% \gamma acceptance the SMD-dos yields \pi^0 rejection efficiency of 92+-4%, 87+-4% and 32+-2%, respectively, for 30, 50 and 150 GeV incident energies. We find that the SMD-dos is superior to a conventional geometry single-layer or mutiple-layer shower maximum detector (SMD), of equal granularity, by an average factor of ~1.5 over the 50 to 150 GeV energy range. We also find that the SMD-dos gives better \pi^0 rejection, for the same number of channels, than a SMD. At hadron - hadron colliders the signature of choice for the detection of the Higgs particle, in the mass range of 120 to 160 GeV, is via the decay H-->\gamma\gamma. The addition of a SMD-dos to the planned detectors at the LHC would significantly reduce the background to the \gamma-signal coming from prolific \pi^0 production.