Searching for the toponium ${\eta}_{t}$ with the ${\eta}_{t}$ ${\to}$ $W^{+}W^{-}$ decay

TL;DR

This paper estimates decay branching ratios of the ${ m exteta}_t$ meson, focusing on the ${ m exteta}_t o W^+W^-$ channel, to guide future experimental searches at the HL-LHC.

Contribution

It provides the first rough estimates of ${ m exteta}_t$ decay modes and event rates, aiding experimental efforts to detect the ${ m exteta}_t$ meson.

Findings

Tens of dilepton events expected from ${ m exteta}_t o W^+W^-$ decay.

Hundreds of events from ${ m exteta}_t o Z^0H$ decay with single $Z^0$ tagging.

Estimates serve as a reference for future experimental searches.

Abstract

Inspired by the observation of the ${\eta}_{t}$ meson at the LHC and the promising prospect of the ${\eta}_{t}$ meson available at the approaching HL-LHC, branching ratios for the ${\eta}_{t}$ ${\to}$ $f\bar{f}$, $gg$, ${\gamma}{\gamma}$, $W^{+}W^{-}$, $Z^{0}Z^{0}$, $Z^{0}{\gamma}$ and $Z^{0}H$ decays are roughly estimated. It is found that tens of opposite-charge dilepton events from the ${\eta}_{t}$ ${\to}$ $W^{+}W^{-}$ decay and hundreds of events from the ${\eta}_{t}$ ${\to}$ $Z^{0}H$ ${\to}$ ${\ell}^{+}{\ell}^{-}H$ decay using the single $Z^{0}$ boson tagging method are expected to be accessible. This estimation provides a reference for future experimental study on the ${\eta}_{t}$ meson.