Post‑Doctoral Research Associate

Czech Technical University in Prague

October 2024 – September 2025 · Prague (CZ)

The top quark, the heaviest known elementary particle, provides a unique probe of the initial state in heavy-ion collisions. In \(\mathrm{Pb}+\mathrm{Pb}\) collisions at the LHC, top quarks decay before the quark–gluon plasma forms, offering an unmodified view of high-energy QCD dynamics. In Phys. Rev. Lett. 134, 142301 (2025), we reported the first 5.0σ observation of top–antitop production in heavy-ion collisions. Key contributions included optimising signal regions, implementing a profile-likelihood multi-fit strategy across various models, and maximising sensitivity in the dilepton final state with high-purity $t\bar{t}$ reconstruction. I leveraged cross-collision expertise from $pp$, $p+\mathrm{Pb}$, and \(\mathrm{Pb}+\mathrm{Pb}\) datasets to refine selection and systematics, ensuring analysis reproducibility through HEPData submissions and promoting transparency and reusability for the global theory community.

Other responsibilities included:

• Contributed to ATLAS software validation efforts, focusing on $b$-tagging performance in high-occupancy environments
• Acted as the ATLAS bJet/ID/MinBias signatures expert-on-call and online coordinator during active data-taking periods
• Initiated Run 3 heavy-ion analysis efforts on \(\mathrm{Pb}+\mathrm{Pb}\) collisions, including early event selection and workflow development
• Led and participated in outreach activities, including public talks, student workshops, and science communication campaigns

Doctoral Researcher

Silesian University in Opava & Czech Technical University in Prague

September 2017 – October 2024 · Prague (CZ)

I completed my Ph.D. as part of the ATLAS Collaboration, focusing on Higgs boson measurements in proton-proton collisions, specifically the $t\bar{t}W$ production channel with multilepton final states, and on top-quark studies in proton-lead ($p+\mathrm{Pb}$) and high-multiplicity proton-proton ($pp$) collisions. My research covered the full data analysis pipeline—from developing statistical and simulation frameworks to presenting results at international conferences and publishing in peer-reviewed journals.

Key contributions during my doctoral research include:

Top-Quark Pair Production in $p+\mathrm{Pb}$ Collisions
Led the first observation of top-quark pair production in a heavy-ion environment at $\sqrt{s_{NN}} = 8.16\ \mathrm{TeV}$ with significance exceeding $5\sigma$. The cross-section was measured with a relative uncertainty of $9\%$, making this the most precise $t\bar{t}$ cross-section determination in nuclear collisions to date. I designed the profile-likelihood framework, managed systematic uncertainties, optimised fit variables, and contributed to pseudo-top reconstruction. This framework was subsequently adapted for \(\mathrm{Pb}+\mathrm{Pb}\) analyses. Results were presented at ICHEP 2024 and Diffraction & Low-x 2024, and published in JHEP 11 (2024) 101.

$t\bar{t}H$ and $t\bar{t}W$ Production in Multilepton Final States
Contributed to measurements using $80\ \mathrm{fb}^{-1}$ of proton-proton collision data at $\sqrt{s_{NN}} = 13\ \mathrm{TeV}$, focusing on the same-sign dilepton plus hadronic tau ($\tau$) channel. Led data-driven background estimation employing a fake-factor (ABCD) method, optimised multivariate discriminants, and supported framework and Monte Carlo (MC) production development. Results were presented at ICHEP 2020.

Flavour-Tagging Calibration for LHC Run 2
Developed and maintained pseudo‑continuous b‑tagging calibration tools using \(139\ \mathrm{fb}^{-1}\) of proton‑proton collision data at $\sqrt{s_{NN}} = 13\ \mathrm{TeV}$. Built validation and visualisation utilities based on CDI files, enhancing consistency across ATLAS releases and analysis readiness. The results published in Eur. Phys. J. C 83, 681 (2023).