Constraints on top quark flavor changing neutral currents using diphoton events at the LHC

Abstract

In this paper we show that the diphoton mass spectrum in proton-proton collisions at the LHC is sensitive to the top quark flavor changing neutral current in the vertices of $tu\gamma$ and $tc\gamma$. The diphoton mass spectrum measured by the CMS experiment at the LHC at a center-of-mass energy of 8 TeV and an integrated luminosity of 19.5 fb${}^{-1}$ is used as an example to set limits on these FCNC couplings. It is also shown that the angular distribution of the diphotons is sensitive to anomalous $tu\gamma$ and $tc\gamma$ couplings and it is a powerful tool to probe any value of the branching fraction of top quark rare decay to an up-type quark plus a photon down to the order of $10^{-4}$. We also show that the $tu\gamma$ FCNC coupling has a significant contribution to the neutron electric dipole moment (EDM) and the upper bound on neutron EDM can be used to constrain the $tu\gamma$ FCNC coupling.

17 pages, 7 figures, an EDM analysis included in addition to the published version

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Cited by in corpus (16)

• Rare Top Decays in Minimal and Non-minimal Universal Extra Dimension
• Probing top quark FCNC couplings in the triple-top signal at the high energy LHC and future circular collider
• Constraining top quark flavor violation and dipole moments through three and four top quark productions at the LHC
• Photon initiated single top quark production via flavor-changing neutral currents at the LHC
• $t\to cg$ and $t\to cZ$ in Universal Extra Dimensional Models
• SM Higgs boson and $t\to cZ$ decays in the 2HDM type III with CP violation
• Top quark anomalous FCNC production via $tqg$ couplings at FCC-hh
• Probing anomalous $tq\gamma$ and $tqg$ couplings via single top production in association with photon at FCC-hh
• Probing the anomalous $tq\gamma$ couplings through single top production at the future lepton-hadron colliders
• Same-sign top pair plus $W$ production in flavor changing vector and scalar models
• Top Rare Decays t-> cV in the Mirror Twin Higgs Models
• Probing FCNC couplings in single top quark production associated with a neutral gauge boson at future lepton colliders
• Probing the anomalous tqgamma couplings in photon-proton collisions
• Top-philic Machine Learning
• Sensitivity analysis for the anomalous $tq\gamma$ couplings via $\gamma q\to t\gamma$ subprocess in photon-proton collisions at the FCC-$\mu$p
• Investigation of the FCNC couplings between the top quark and the photon in $\gamma \gamma$ and ${\gamma }^{\ast }{\gamma }^{\ast }$ collisions at the CLIC