# Studies of $Z\gamma$ production in association with a high-mass dijet system in $pp$ collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector

## TL;DR

This paper measures Zγ production with high-mass dijets at 8 TeV, analyzing electroweak processes and setting limits on anomalous couplings, with no deviations from the Standard Model observed.

## Contribution

First measurement of Zγ production with high-mass dijets at 8 TeV, including electroweak cross-sections and constraints on anomalous couplings using ATLAS data.

## Key findings

- Electroweak and total Zγ + dijet cross-sections measured.
- No deviations from Standard Model predictions found.
- Constraints placed on anomalous vector boson couplings.

## Abstract

The production of a $Z$ boson and a photon in association with a high-mass dijet system is studied using 20.2fb$^{-1}$ of proton-proton collision data at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV recorded with the ATLAS detector in 2012 at the Large Hadron Collider. Final states with a photon and a Z boson decaying into a pair of either electrons, muons, or neutrinos are analysed. Electroweak and total $pp \to Z\gamma j j$ cross-sections are extracted in two fiducial regions with different sensitivities to electroweak production processes. Quartic couplings of vector bosons are studied in regions of phase space with an enhanced contribution from pure electroweak production, sensitive to vector-boson scattering processes $VV \to Z\gamma$. No deviations from Standard Model predictions are observed and constraints are placed on anomalous couplings parameterized by higher-dimensional operators using effective field theory.