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

Abstract

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 $t\to b\bar{b}c$. Three are invariant mass-squared distributions involving two of the final-state particles in the top decay, and three are angular correlations between the final-state quarks coming from the $t$ decay and the ${\ell }^{-}$ coming from the $\bar{t}$ decay. The angular correlations are related to the $t\bar{t}$ spin correlation.

Published version

References in corpus (10)

• FeynRules 2.0 - A complete toolbox for tree-level phenomenology
• FeynRules - Feynman rules made easy
• Theoretical status and prospects for top-quark pair production at hadron colliders
• Top pair invariant mass distribution: a window on new physics
• Spin Correlation Effects in Top Quark Pair Production at the LHC
• Measurements of t t-bar spin correlations and top-quark polarization using dilepton final states in pp collisions at sqrt(s) = 7 TeV
• Measurement of ttbar Spin Correlation in ppbar Collisions Using the CDF II Detector at the Tevatron
• Top quark spin correlations in the Randall-Sundrum model at the CERN Large Hadron Collider
• T-odd correlations from CP violating anomalous top-quark couplings revisited
• Detecting New Physics in Rare Top Decays at the LHC

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• On two-body and three-body spin correlations in leptonic $t\bar{t}Z$ production and anomalous couplings at the LHC
• Measuring CP-Violating Observables in Rare Top Decays at the LHC
• Detecting New Physics in Rare Top Decays at the LHC
• Single-top production and rare top interactions