Search for New Physics in Rare Top Decays: $t \bar t$ Spin Correlations and Other Observables

Understand

In this paper we study new-physics contributions to the top-quark decay $t \to b \bar b c$.

• We search for ways of detecting such new physics via measurements at the LHC.
• As top quarks are mainly produced at the LHC in $t \bar t$ production via gluon fusion, we analyze the process $gg \to t \bar t \to (b \bar b c) (\bar b \ell \bar \nu)$.
• We find six observables that can be used to reveal the presence of new physics in $t \to b \bar b c$.