Towards the Observation of Signal over Background in Future Experiments

TL;DR

This paper introduces a new significance measure for future high energy physics experiments to better estimate the probability of discovering new physics, accounting for statistical and systematic uncertainties.

Contribution

It proposes a novel significance formula for large event counts and a method to incorporate systematic errors in background and signal estimates.

Findings

New significance measure S_{12} improves discovery probability estimates.

Method to include systematic uncertainties enhances analysis accuracy.

Applicable to supersymmetry searches at LHC.

Abstract

We propose a method to estimate the probability of new physics discovery in future high energy physics experiments. Physics simulation gives both the average numbers $<N_b>$ of background and $<N_s>$ of signal events. We find that the proper definition of the significance for $<N_b>, <N_s> \gg 1$ is $S_{12} = \sqrt{<N_s>+<N_b>} - \sqrt{<N_b>}$ in comparison with often used significances $S_1 = <N_s>/\sqrt{<N_b>}$ and $S_2 = <N_s>/\sqrt{<N_s> + <N_b>}$. We also propose a method for taking into account the systematical errors related to nonexact knowledge of background and signal cross sections. An account of such systematics is very essential in the search for supersymmetry at LHC.