arXiv subjects

J. Smiesko

Publications and source records attributed to J. Smiesko.

4 recordsLinked to original sources

arXiv2025

tZ FCNC Case study: LLM Application in signal/Background discrimination analyses in Particle Physics

We present a case study exploring the potential of OpenAI's o3 model as a process-agnostic tool (within fixed topology) for predicting optimized selection cuts in high-energy physics analyses. Specifically, we investigate the effectiveness of the model in separating signal from relevant Standard Model backgrounds in the context of Flavour-Changing Neutral Current (FCNC) top-quark couplings, focusing on the rare decay process t \rightarrow uZ. The study is performed at the Future Circular Collider in hadron-hadron mode (FCC-hh) setup. We prompt the o3 model on detector level data for signal and background processes to predict selection cuts that enhance Signal-to-Background (S/B) discrimination. A comparative analysis is then carried out between the efficiencies resulting from o3-predicted cuts, TMVA BDT separation and those derived from traditional manually designed strategies used by a control group; all utilizing the same parameters for the sake of the integrity of the study. Our results demonstrate that the o3 model performs a degree better than the control group, suggesting its promise as a fast and generalizable tool for new physics searches. Meanwhile, BDT results were considerably higher than both the o3 and the traditional cut-based methods. Furthermore, in order to test its limitations, o3 cuts were applied to data generated via the approved High-Luminosity Large Hadron Collider (HL-LHC) and the proposed High-Energy LHC (HE-LHC) setup in order to examine its effectiveness at different energy scales when provided with data at FCC energies.

hep-ph↗

arXiv2020

Novel Heavy-Quark Physics Phenomena

We review the current understanding of heavy quark parton distributions in nucleons and their impact on deep inelastic scattering, collider physics, and other processes at high energies. The determination of the heavy-quark parton distribution functions is particularly significant for the analysis of hard processes at LHC energies, including the forward rapidity high $x_\mathrm{F}$ domain. The contribution of "intrinsic" heavy quarks, which are multiply connected to the valence quarks of nucleons, is reviewed within non-perturbative physics which provides new information on the fundamental structure of hadrons in QCD. A new prediction for the non-perturbative intrinsic charm-anticharm asymmetry of the proton eigenstate has recently been obtained from a QCD lattice gauge theory calculation of the proton's $G_\mathrm{E}^p(Q^2)$ form factor. This form factor only arises from non-valence quarks and anti-quarks if they have different contributions in the proton's eigenstate. This result, together with the exclusive and inclusive connection and analytic constraints on the form of hadronic structure functions from Light-Front Holographic QCD (LFHQCD) predicts a significant non-perturbative $c(x,Q) - \bar{c}(x,Q)$ asymmetry in the proton structure function at high $x$, consistent with the dynamics predicted by intrinsic charm models. Recent ATLAS data on the associated production of prompt photons and charm-quark jets in $pp$ collisions at $\sqrt{s} = 8$ TeV has provided new constraints on non-perturbative intrinsic charm and tests of the LGTH predictions. We also focus on other experimental observables which have high sensitivity to the intrinsic heavy contributions to PDFs.

hep-ph↗

arXiv2018

Constraints on the intrinsic charm content of the proton from recent ATLAS data

Constraints on the intrinsic charm probability $\wccm = P_{{\mathrm{c}\bar \mathrm{c}} / \mathrm{p}}$ in the proton are obtained for the first time from LHC measurements. The ATLAS Collaboration data for the production of prompt photons, accompanied by a charm-quark jet in pp collisions at $\sqrt s = 8 $ TeV, are used. The upper limit \mbox{$\wccm < 1.93$~\%} is obtained at the 68~\% confidence level. This constraint is primarily determined from the theoretical scale and systematical experimental uncertainties. Suggestions for reducing these uncertainties are discussed. The implications of intrinsic heavy quarks in the proton for future studies at the LHC are also discussed.

hep-ph↗

arXiv2016

The Physics of Heavy Quark Distributions in Hadrons: Collider Tests

We present a review of the current understanding of the heavy quark distributions in the nucleon and their impact on collider physics. The origin of strange, charm and bottom quark pairs at high light-front (LF) momentum fractions in hadron wave functions---the "intrinsic" quarks, is reviewed. The determination of heavy-quark parton distribution functions (PDFs) is particularly significant for the analysis of hard processes at LHC energies. We show that a careful study of the inclusive production of open charm and the production of $γ$/$Z$/$W$ particles, accompanied by the heavy jets at large transverse momenta can give essential information on the intrinsic heavy quark (IQ) distributions. We also focus on the theoretical predictions concerning other observables which are very sensitive to the intrinsic charm contribution to PDFs including Higgs production at high xf and novel fixed target measurements which can be tested at the LHC.

hep-ph↗