Constraining the Intrinsic Structure of Top-Quarks

TL;DR

This paper investigates the fundamental structure of top-quarks by setting experimental limits on their intrinsic properties, such as radius and magnetic moment, using collider data from Tevatron and LHC, and proposes future measurement strategies.

Contribution

It provides the first experimental constraints on top-quark intrinsic structure parameters and suggests improved future limits using boosted top and $t\bar{t}+jet$ analyses.

Findings

Upper limits on top-quark radius and magnetic dipole moment derived from Tevatron and LHC data.

Predicted improved limits for future LHC analyses, especially with boosted top states.

Proposed methods for measuring intrinsic parameters using $t\bar{t}+jet$ final states.

Abstract

The basic structure of top-quarks as spin-1/2 particles is characterized by the radius $R_t$ and the intrinsic magnetic dipole moment $\kappa_t$, both individually associated with gauge interactions. They are predicted to be zero in pointlike theories as the Standard Model. We derive upper limits of these parameters in the color sector from cross sections measured at Tevatron and LHC in top-pair production $p{\bar{p}}/pp \to t{\bar{t}}$, and we predict improved limits expected from LHC in the future, especially for analyses exploiting boosted top final states. An additional method for measuring the intrinsic parameters is based on $t \bar{t} + jet$ final states.