Double Flavor Violating Top Quark Decays in Effective Theories

TL;DR

This paper investigates the potential for observing rare double flavor violating top quark decays mediated by the Higgs boson, using effective theories and current experimental constraints, suggesting possible detectable signals at the LHC.

Contribution

It provides a model-independent analysis of double flavor violating top decays and estimates their branching ratios within current experimental limits.

Findings

Standard Model predicts extremely small branching ratios (~10^{-13} to 10^{-14})

Higgs-mediated decays could have branching ratios of 10^{-3} to 10^{-4}

Potential detectability at the CERN LHC for certain Higgs mass ranges

Abstract

The possibility of detecting double flavor violating top quark transitions $t \to u_i\tau \mu$ ($u_i=u,c$) is explored in a model--independent manner, using the effective Lagrangian approach. Low--energy data, on high precision measurements, and current experimental limits are used to constraint the $tu_iH$ and $H\tau \mu$ vertices and then to calculate the branching ratio BR$(t \to u_i\tau \mu)$. If in the Standard Model BR$(t \to u_i\tau \mu)$ is of the order of $10^{-13}$$-10^{-14}$, higgs--mediated double flavor violating top quark decays can occur with branching ratios ranging from $10^{-3}$ to $10^{-4}$ for 114.4 GeV$/c^2$ $< m_H<$ $2m_W$, that is at the reach of the CERN Large Hadron Collider.