English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

A search for singly produced vector-like $T/Y$ quark is performed inproton-proton collision data at a centre-of-mass energy of $13$ TeVcorresponding to an integrated luminosity of $139.1 fb^{-1}$, recorded with theATLAS detector at the LHC from 2015-18. The analysis focused on the hadronicchannel of $T/Y \rightarrow Wb$ decay mode. The hadronic channel is not a cleanchannel, unlike the leptonic channel, because of the contribution coming fromthe QCD processes, which accounts for a significant background. The modellingof QCD processes is challenging due to their theoretical prediction andexperimental challenges. Due to this, it is observed that the Monte Carlosimulation of the QCD multijet is mismodelled in this analysis. In this thesis,a data-driven method called the ABCD method is presented to estimate the QCDmultijet background. The method uses the background events from all the controlregions to estimate the multijets in the signal region. However, a correlationamong different control regions is observed, which is further accounted byintroducing a correlation factor. The correlation factor is calculated byperforming likelihood fit to the MC simulated backgrounds. Some additionalstudies, including uncertainty estimation on the method and the performance ofthe method with different jet collections and taggers, are also performed.

Background estimation in the search for single production of vector-like  quarks decaying into $Wb$ in $pp$ collisions using a data-driven method at  $\sqrt{s} = 13$ TeV with the ATLAS detector