Speaker
Description
The study present the measurement of the contribution, purity, of $Z + \gamma$ and $Z+$ jet background events in the search for high-mass $Z\gamma$ resonances. The study uses events were the $Z$ boson decays into a pairs of oppositely charged electrons or muons. The events used consist of 139 fb${}^{-1}$ of proton-proton, $pp$, collisions data at $\sqrt{s} = 13$ TeV, recorded by the ATLAS detector at the CERN Large Hadron Collider.
The measured purity of $Z+\gamma$ background events depends on the parameter $R$ that gives the correlation between the isolation and identification criteria for jets faking photons in $Z+$ jet events. A data-driven method that uses $\gamma\gamma$ events collected in the same detector conditions as the $Z\gamma$ events is used to determine $R$ in various bins of the photon transverse momentum or the invariant mass bins. The results are compared against results that are obtained using the $R$ computed using a $Z+$jet Monte Carlo sample and a data-driven method that uses $Z+\gamma$ events to estimate $R$.
Apply to be considered for a student ; award (Yes / No)?
Yes
Level for award;(Hons, MSc, PhD, N/A)?
PhD
