Limits on Quark Compositeness from High Energy Jets in PbarP Collisions at 1.8 TeV

TL;DR

This paper uses high-energy jet events from proton-antiproton collisions at 1.8 TeV to establish lower bounds on the energy scale of quark substructure, finding no deviation from standard QCD predictions.

Contribution

It provides the first experimental lower limit of 2.0 TeV on quark compositeness scale using jet data at Tevatron energies.

Findings

Data are consistent with next-to-leading order QCD.

Set a 95% confidence lower limit of 2.0 TeV on Lambda_LL.

Limits are insensitive to interference sign.

Abstract

Events in PbarP collisions at sqrt(s)=1.8 TeV with total transverse energy exceeding 500 GeV are used to set limits on quark substructure. The data are consistent with next-to-leading order QCD calculations. We set a lower limit of 2.0 TeV at 95% confidence on the energy scale Lambda_LL for compositeness in quarks, assuming a model with a left-left isoscalar contact interaction term. The limits on Lambda_LL are found to be insensitive to the sign of the interference term in the Lagrangian.