Collider signals of maximal flavor violation: Same-sign leptons from same-sign top quarks at the Fermilab Tevatron

Abstract

In models of maximal flavor violation (MxFV) suggested in [S. Bar-Shalom and A. Rajaraman, Phys. Rev. D 77, 095011 (2008).] there is at least one new scalar ${\ensuremath{\Phi}}_{\mathrm{FV}}$ which couples to the quarks via ${\ensuremath{\Phi}}_{\mathrm{FV}}{q}_{i}{q}_{j}\ensuremath{\propto}{\ensuremath{\xi}}_{ij}$ where ${\ensuremath{\xi}}_{i3},{\ensuremath{\xi}}_{3i}\ensuremath{\sim}{V}_{tb}$ for $i=1$, 2 and ${\ensuremath{\xi}}_{33}\ensuremath{\sim}{V}_{td}$ and $V$ is the CKM matrix. In this article, we explore the potential phenomenological implications of MxFV for collider experiments. We study MxFV signals of same-sign leptons from same-sign top-quark pair production at the Tevatron and at the LHC. We show that the current Tevatron data set has strong sensitivity to this signature, for which there are no current limits. For example, if ${m}_{{\ensuremath{\Phi}}_{\mathrm{FV}}}\ensuremath{\sim}200\text{ }\text{ }\mathrm{GeV}$ and the MxFV coupling $\ensuremath{\xi}$ has a natural value of $\ensuremath{\sim}1$, we expect $\ensuremath{\sim}12$ MxFV events to survive a selection requiring a pair of same-sign leptons, a tagged $b$-jet and missing transverse energy, over a background of approximately 4--5 events.