# Search for new physics in top quark production in dilepton final states in proton-proton collisions at $\sqrt{s} =$ 13 TeV

## TL;DR

This study searches for signs of new physics in top quark production at 13 TeV using CMS data, focusing on dilepton final states, and sets constraints on effective couplings without observing deviations from the standard model.

## Contribution

It introduces a novel analysis separating tW from top pair events and uses effective field theory to constrain new physics couplings.

## Key findings

- No significant deviation from the standard model observed.
- Constraints set on effective couplings in top quark production.
- Distinct analysis of tW process enhances sensitivity to new physics.

## Abstract

A search for new physics in top quark production is performed in proton-proton collisions at 13 TeV. The data set corresponds to an integrated luminosity of 35.9 fb$^{-1}$ collected in 2016 with the CMS detector. Events with two opposite-sign isolated leptons (electrons or muons), and b quark jets in the final state are selected. The search is sensitive to new physics in top quark pair production and in single top quark production in association with a W boson. No significant deviation from the standard model expectation is observed. Results are interpreted in the framework of effective field theory and constraints on the relevant effective couplings are set, one at a time, using a dedicated multivariate analysis. This analysis differs from previous searches for new physics in the top quark sector by explicitly separating tW from $\mathrm{t}\bar{\mathrm{t}}$ events and exploiting the specific sensitivity of the tW process to new physics.