Using associated top quark production to probe for new physics within the framework of effective field theory

TL;DR

This paper uses top quark production events at the LHC to constrain new physics effects modeled by an effective field theory, analyzing data to set limits on 16 Wilson coefficients.

Contribution

It introduces a novel parameterization of 16 dimension-six EFT operators and performs a simultaneous fit to LHC data to extract confidence intervals for their Wilson coefficients.

Findings

Most Wilson coefficient intervals include the Standard Model value zero.

No statistically significant deviation from the Standard Model was observed.

The method constrains new physics effects in top quark production.

Abstract

Signs of new physics are probed in the context of an Effective Field Theory using events containing one or more top quarks in association with additional leptons. Data consisting of proton-proton collisions at a center-of-mass energy of $\sqrt{s}=$13 TeV was collected at the LHC by the CMS experiment in 2017. We apply a novel technique to parameterize 16 dimension-six EFT operators in terms of the respective Wilson coefficients (WCs). A simultaneous fit is performed to the data in order to extract the two standard deviation confidence intervals (CIs) of the 16 WCs. The Standard Model value of zero is completely contained in most CIs, and is not excluded by a statistically significant amount in any interval.