arXiv subjects

Matei S. Filip

Publications and source records attributed to Matei S. Filip.

2 recordsLinked to original sources

arXiv2026

Observability of an ultraheavy diquark decaying into vectorlike quarks at the LHC

We present a comprehensive analysis of the discovery reach and exclusion limits for an ultraheavy diquark scalar (7-9.5 TeV) decaying into a pair of vectorlike quarks (1.5-2 TeV) at the HL-LHC. Building on an improved signal selection efficiency achieved using Machine Learning techniques, we extend our previous six-jet final-state study by providing a complete likelihood-based statistical treatment of this search topology. The analysis incorporates theoretical and systematic uncertainties through nuisance parameters within the likelihood framework, enabling a consistent statistical interpretation. The mass regions of interest were determined through scans of the local $p$-values, $CL_s$, and the upper limits on the model-dependent signal strength $μ$. The results indicate a promising sensitivity to ultraheavy diquark scalars within the explored mass range, suggesting that the HL-LHC could either discover or set stringent exclusion limits on such particles.

hep-ph↗

arXiv2026

HL-LHC sensitivity to an ultraheavy $S_{uu}$ diquark in the $uχ$ channel

We study the HL-LHC sensitivity to an ultraheavy diquark $S_{uu}$ produced in up-quark fusion and decaying as $S_{uu}\to uχ$, $χ\to Wb, Zt, h^0t$. For fully hadronic decays of the W, Z and top quark, this gives rise to multijet final states. Within the same model framework used previously for the $S_{uu}\toχχ$ six-jet channel, we consider $S_{uu}$ masses in the multi-TeV range and vectorlike quark masses of order a few TeV, and simulate proton-proton collisions at $\sqrt s = 13.6$ TeV with integrated luminosities up to the HL-LHC target. The analysis strategy employs a machine-learning-based discriminant adapted from the six-jet study to the new four-jet topology, which we use to derive the corresponding discovery reaches and exclusion limits. We find that this topology improves the overall sensitivity to $S_{uu}$ in regions where the branching ratio $B(S_{uu}\to uχ)$ is sizable and provides a complementary signature for studying ultraheavy diquarks at the HL-LHC.

hep-ph↗