Implications of the Measurement of Ultra-Massive Boosted Jets at CDF

TL;DR

This paper analyzes the CDF measurement of ultra-massive boosted jets, exploring implications for new physics, including a light gluino model, and discusses deviations from QCD predictions.

Contribution

It provides a detailed interpretation of the CDF boosted jet data and examines potential new physics explanations, such as a light gluino with R-parity violation.

Findings

Deviation from QCD predictions at high planarity

Possible consistency of light gluino model with data

Tension between large top pair cross section and observed events

Abstract

The CDF collaboration recently reported an upper limit on boosted top pair production and noted a significant excess above the estimated background of events with two ultra-massive boosted jets. We discuss the interpretation of the measurement and its fundamental implications. In case new physics is involved, the most naive contribution is from a new particle produced with a cross section that is a few times higher than that of the top quark and a sizable hadronic branching ratio. We quantify the resulting tension of a possible larger top pair cross section with the absence of excess found in events with one massive boosted jet and missing energy. The measured planar flow distribution shows deviation from CDF's Pythia QCD prediction at high planarity, while we find a somewhat smaller deviation when comparing with other Monte Carlo tools. As a simple toy model, we analyze the case of a light gluino with R-parity violation and show that it can be made consistent with the data.