General Search for New Phenomena in ep Scattering at HERA

TL;DR

This paper conducts a comprehensive, model-independent search for deviations from the Standard Model in ep scattering at HERA, analyzing various event topologies and introducing a new algorithm to identify significant anomalies.

Contribution

It presents a novel, model-independent method with a new algorithm to detect deviations in high-energy collision data, confirming previous anomalies with statistical significance.

Findings

Most event classes agree with the Standard Model.

A notable deviation was observed in muon, missing transverse momentum, and jet topologies.

Approximately 2% of simulated experiments show more significant deviations than observed.

Abstract

A model-independent search for deviations from the Standard Model prediction has been performed in e+p and e-p collisions at HERA using H1 data. All experimentally measurable event topologies involving isolated electrons, photons, muons, neutrinos and jets with high transverse momenta have been investigated. A good agreement with the Standard Model prediction is found in most of the event classes. A new algorithm has been developed to look for regions with large deviations from the Standard Model in the invariant mass and sum of transverse momenta distributions and to quantify the significance of the fluctuations observed. The largest deviation is found in topologies with an isolated muon, missing transverse momentum and a jet which confirms previous observations. About 2% of hypothetical Monte Carlo experiments would produce deviations more significant than the one observed in the corresponding distribution of sum of transverse momenta.