Description
We study the discovery potential of LHC experiments for resonantly produced vectorlike quarks ($\chi$), when the s-channel resonance is an ultraheavy diquark scalar particle ($S_{uu}$) of mass in the $7-8.5$ TeV range. Given that the $S_{uu}$ resonance can be reconstructed when both $W^+$ bosons decay hadronically, we focus on the 6-jet final state arising from the $pp \rightarrow S_{uu} \rightarrow\chi\chi\rightarrow (W^+b)(W^+b)$ process. The signal selection study is done by employing Machine Learning algorithms to construct a multidimensional signal-from-background discriminator. Our results indicate that ATLAS or CMS searches in the above 6-jet final state with a luminosity of $3000 \ \text{fb}^{-1}$ may discover or rule out a diquark scalar of mass near 8 TeV even when its yukawa coupling to up quarks is as small as $y_{uu} \approx 0.2$. We also discuss preliminary results on the 4-jet final state of $pp \rightarrow S_{uu} \rightarrow u \chi\rightarrow u (W^+b)$.
