Measurement of the W$\gamma$ production cross section in proton-proton collisions at $\sqrt{s} =$ 13 TeV and constraints on effective field theory coefficients

TL;DR

This paper measures the Wγ production cross section at 13 TeV using CMS data, compares it with theoretical predictions, and sets limits on anomalous gauge couplings within an effective field theory framework.

Contribution

It provides the first measurement of Wγ production cross section at 13 TeV and constrains new physics via effective field theory coefficients.

Findings

Measured Wγ cross section consistent with NLO QCD predictions.

Set 95% CL limits on anomalous triple-gauge couplings.

Used 137 fb$^{-1}$ of CMS data for analysis.

Abstract

A fiducial cross section for W$\gamma$ production in proton-proton collisions is measured at a center-of-mass energy of 13 TeV in 137 fb$^{-1}$ of data collected using the CMS detector at the LHC. The W $\to$ e$\nu$ and $\mu\nu$ decay modes are used in a maximum-likelihood fit to the lepton-photon invariant mass distribution to extract the combined cross section. The measured cross section is compared with theoretical expectations at next-to-leading order in quantum chromodynamics. In addition, 95% confidence level intervals are reported for anomalous triple-gauge couplings within the framework of effective field theory.