Search for anomalous tq$\gamma$ FCNC Couplings in direct single top quark production at the LHC

TL;DR

This paper investigates the potential of using direct single top quark production at the LHC to probe flavor-changing neutral current interactions involving the top quark and photons, setting new bounds on their decay probabilities.

Contribution

It reinterprets existing 8 TeV ATLAS data to establish upper limits on FCNC top decays and estimates future sensitivity at 13 TeV with different luminosities.

Findings

Upper bounds on ${ m B}(t o u\gamma)$ and ${ m B}(t o c\gamma)$ are set.

Reinterpretation of 8 TeV data constrains FCNC interactions.

Sensitivity projections for 13 TeV are provided.

Abstract

In this paper we propose and study direct single top quark production channel for probing the tq$\gamma$ flavor-changing neutral current (FCNC) interactions at the LHC. We reinterpret the experimental results of a search for direct single top quark production performed by ATLAS collaboration at 8 TeV to set upper bounds on the FCNC top quark decay branching fractions through the proposed channel, resulting in ${\cal B}$(t$\rightarrow$ u$\gamma$) $<$ 0.05\% and ${\cal B}$(t$\rightarrow$ c$\gamma$) $<$ 0.14\%. Finally, the expected sensitivity at 13 TeV for various integrated luminosity scenarios is estimated.