Measurement of the electroweak production of W$\gamma$ in association with two jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV

TL;DR

This paper reports a precise measurement of electroweak Wγ production with two jets at 13 TeV, confirming Standard Model predictions and setting new limits on anomalous gauge couplings.

Contribution

First measurement of electroweak Wγjj production at 13 TeV with detailed differential cross sections and stringent constraints on anomalous quartic gauge couplings.

Findings

Electroweak Wγjj cross section measured as 23.5 fb.

Total Wγjj production cross section is 113 fb.

Most stringent limits to date on certain anomalous gauge couplings.

Abstract

A measurement is presented for the electroweak production of a W boson, a photon ($\gamma$), and two jets (j) in proton-proton collisions. The leptonic decay of the W boson is selected by requiring one identified electron or muon and large missing transverse momentum. The two jets are required to have large invariant dijet mass and large separation in pseudorapidity. The measurement is performed with the data collected by the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. The cross section for the electroweak W$\gamma$jj production is 23.5 $^{+4.9}_{-4.7}$ fb, whereas the total cross section for W$\gamma$jj production is 113 $\pm$ 13 fb. Differential cross sections are also measured with the distributions unfolded to the particle level. All results are in agreement with the standard model expectations. Constraints are placed on anomalous quartic gauge couplings (aQGCs) in terms of dimension-8 effective field theory operators. These are the most stringent limits to date on the aQGCs parameters $f_\mathrm{M,2-5}$ $/$ $\Lambda^4$ and $f_\mathrm{T,6-7}$ $/$ $\Lambda^4$.