We offer the possibility to present posters during the event.
The abstracts can be sent to sfof2026@us.edu.pl till 15 October.
Posters
1. Grzegorz Ziarko, “Gluon saturation in dijet and trijet production at LHμC”.
Abstract:
This poster presents the latest predictions for dijet and trijet production at the proposed Large Hadron-Muon Collider (LHμC). The study evaluates collisions of 1 TeV muons with 2.76 TeV and 7 TeV protons at the HL-LHC, corresponding to centre-of-mass energies of √sμp = 3.3 TeV or 5.3 TeV - significantly higher than at the proposed FCC-eh. To investigate gluon saturation effects, collisions of muons with lead nuclei are also considered.
2. Sergio Arbiol, “Search for diffractive photon+jet production with the ATLAS Forward Proton detectors at √s = 13.6 TeV”.
Abstract:
Photon+jet production is one of the main Standard Model processes studied at the LHC and gives direct sensitivity to the quark and gluon structure of the proton. In diffractive events, photon+jet production probes the Pomeron instead. Because the dominant production mechanism involves quarks, it is sensitive to the Pomeron's quark component and can test the flavour-symmetric assumption u = d = s used in HERA-based diffractive PDFs. The characteristic signature of a diffractive event is an intact proton that loses a fraction of its energy, is deflected from the beam and can be detected in dedicated forward detectors. This poster presents a search for diffractive photon+jet production with the ATLAS detector and the ATLAS Forward Proton (AFP) system, using a dedicated low-pile-up data set recorded in 2022 (ATLAS run 428770, 29.65 nb⁻¹ at √s = 13.6 TeV). Low pile-up is needed to suppress the combinatorial background, in which an unrelated proton from another proton–proton interaction in the same bunch crossing is accidentally tagged in AFP. Each low-pile-up run has its own detector configuration, so the performance studies were done specifically for this data set: AFP pixel defect maps, tracking efficiency and alignment, jet and AFP trigger efficiencies, and photon identification and isolation. Events are selected by requiring an isolated photon, a good-quality jet in a back-to-back topology, a single reconstructed vertex and a proton reconstructed in AFP. We measure a visible cross-section for non-diffractive photon+jet production and identify candidate single-diffractive and double-Pomeron-exchange events. After accounting for backgrounds from photon misidentification and accidental proton tags, we set 95% confidence-level upper limits on the visible cross-sections of the single-diffractive channels.
3. Maria Dudek, “Search for H+→τν with the ATLAS detector”.
Abstract:
Charged Higgs bosons provide a direct probe of extended Higgs sectors and are predicted by a variety of theories beyond the Standard Model. This poster presents the ATLAS Run 2 results of searches for charged Higgs bosons decaying to a tau lepton and a neutrino, using 140fb-1 of proton-proton collision data recorded at √s = 13 TeV, as well as the strategy of the ongoing analysis targeting data from Run 2 and 3. Depending on the charged Higgs boson mass, the signal is searched for in two production regimes: through top-quark decays and in association with a top quark. Both analyses target final states with a hadronically decaying tau lepton and either jets or a light lepton from an associated W or Z boson, corresponding to the +jets and +lepton channels. No significant excess above the Standard Model background expectation is observed in the completed Run 2 analysis.
4. Grzegorz Jędrzejowski, “CMS upgrade fo HL-LHC” (Polish CMS group Faculty of Physics University of Warsaw).
Abstract:
The upgrade to the High-Luminosity Large Hadron Collider (HL-LHC) introduces an unprecedented increase in the luminosity and complexity of recorded events. This poster presents how the Compact Muon Solenoid (CMS) experiment answers these demanding conditions by undergoing comprehensive changes, including upgrading the muon Level-1 Trigger (L1T) system to feature an enhanced Global Muon Trigger (GMT). By incorporating state-of-the-art detection technologies and integrating advanced computational algorithms, the upgraded GMT is expected to deliver significant performance improvements and new operational capabilities. These technical advancements are essential for maintaining high triggering efficiency in extreme pileup environments, ultimately expanding the CMS experiment's sensitivity to novel physics processes involving muons and deepening our understanding of fundamental particle interactions.
5. Nikodem Witkowski, “The Δ(1232) resonance as a probe of thermal freeze-out”.
Abstract:
The Δ(1232) resonance provides a direct link between the hadronic density of states and the thermodynamic conditions at freeze-out. We study its four charge states in the 10% most central Au–Au collisions at √sNN = 2.42 GeV using a thermal model with spherical and spheroidal flow fields, broad resonance mass distributions, and covariant two-body decays. We distinguish the P33 phase-shift density of states used in thermal production from effective line shapes describing reconstructed pπ pairs. The pair spectra favour the Cugnon and effective phase-shift parametrizations, whereas the charge-resolved Δ yields favour the high-temperature freeze-out branch. The absolute comparison remains sensitive to the invariant-mass integration window, with proton and pion observables providing an independent consistency test.
6. Karol Sowa, “Recent Progress in CKM Angle γ Measurements at LHCb”.
Abstract:
Over the years, the LHCb experiment has played a leading role in precision measurements of the Cabibbo-Kobayashi-Maskawa (CKM) matrix and the study of CP violation in the Standard Model. In particular, LHCb has made a major contribution to the world-average precision on the CKM angle γ. This poster presents the latest results from the LHCb collaboration, including the first measurement of γ with the upgraded LHCb detector, as well as the most recent combination of measurements from the charm sector. It will be complemented by the discussion of γ measurements in the beauty sector, with particular emphasis on the ongoing Bs0→ DsK* analysis.
7. Hubert Paszkiewicz, “Search for the rare decay Bs0→ μ⁺μ⁻γ at the CMS experiment”.
Abstract:
This poster presents the search for the rare decay Bs0→ μ⁺μ⁻γ at the CMS experiment. The related decay Bs0 → μ⁺μ⁻ has already been observed, whereas its radiative counterpart, with an additional photon in the final state, has not yet been observed experimentally. As a flavour-changing neutral-current (FCNC) process, this decay is strongly suppressed in the Standard Model, making its detection challenging. The poster gives a brief overview of the CMS detector and its trigger system, and summarises the CMS results for Bs0 → μ⁺μ⁻. It then introduces the search strategy for Bs0 → μ⁺μ⁻γ and discusses prospects for its observation. Particular attention is paid to trigger efficiency, detector acceptance, and the reconstruction of primary and secondary vertices, which determine how effectively signal events can be selected and identified.
8. Jan Ferdyan, “Drell-Yan structure functions in Z-boson production within the kT-factorization framework”.
Abstract:
The Drell-Yan structure functions in Z-boson production are studied within the kT-factorization framework, with particular emphasis on the Lam-Tung combination. The role of initial partons' transverse momenta is investigated by considering two dominant tree-level partonic channels: the scattering of two off-shell gluons and the scattering of a valence quark with an off-shell gluon. Predictions obtained using several gluon transverse momentum distribution (TMD) models are compared with ATLAS measurements. The results demonstrate that the structure functions are sensitive to the choice of gluon TMD model, while a reasonably good description of the Lam–Tung combination is obtained with some of the considered models.
9. Igor Di Tota, “Amplitude model for 5-body b → sℓ−ℓ+ decays”.
Abstract:
The purpose of this work is to study the B+ → K+π+π−ℓ−ℓ + decay and provide the theoretical model for a full amplitude analysis of the differential decay rate. The quark-level transition that induces the process is a b → sℓ−ℓ+ Flavour-Changing Neutral Current (FCNC) transition. In the Standard Model (SM), this can only occur through one-loop electroweak diagrams, rendering it extremely suppressed, with a branching ratio of 10−6 or less. FCNC transitions such as b → sℓ−ℓ+, are highly valuable probes where SM and New Physics effects are comparable, making the recent anomalies observed by LHCb in these decay channels particularly intriguing. For this reason, the theoretical model for studying this transition in a five-body decay is provided. In fact, it is the first time such a high multiplicity b → sℓ−ℓ+ decay is studied in an inclusive amplitude analysis. The rich spectroscopy of the final hadronic state, which arises from direct production or intermediate resonances, enables classification of the decay channels into three resonant topologies and one non-resonant topology. After computing the five-body phase space, the main effective theories necessary for describing the FCNC transition have been introduced. The parameterization for the matrix elements of the hadronic transition is provided, both in the full theory and in the Heavy-Quark and Large-Energy limits. At the level of the mesons involved, the B → K(∗)Jℓ−ℓ+ transition is described using helicity amplitudes, which allow the decay amplitude to be constructed in the helicity formalism. The differential decay rate for the B+ → K+π+π−ℓ−ℓ+ decay is presented in terms of angular variables and invariant masses, so as to directly connect the theoretical predictions with experimental distributions, thus paving the way for future full amplitude analysis of the decay on real data collected by the LHCb experiment.
10. Roman Hladun, “Annihilators for the Maximal Cut of Feynman Integrals in the Baikov Representation”.
Abstract:
We present an algorithm based on Griffiths–Dwork reduction for determining annihilators of dimensionally regularized Feynman integrals in the Baikov representation. For Feynman integrals on the maximal cut, we apply the method to determine the annihilating ideal, investigate its properties, such as the holonomic rank and singular locus, and construct the associated Picard–Fuchs operator. Among other examples, we study integrals for the NNLO Bhabha scattering.
11. Manuel López, “Towards NNLO QCD corrections to polarized W+ Z production with semileptonic decay”.
Abstract:
In the absence of fundamental discoveries beyond the Standard Model, precision predictions for electroweak processes remain essential for probing windows to new physics, such as the mechanism of electroweak symmetry breaking (EWSB), within reach of future colliders. Among the tools for testing the standard realization of EWSB we have the polarized production of gauge bosons, which at high energies are connected to Higgs mechanics through the Goldstone boson equivalence theorem, making them particularly relevant observables in searches for potential new physics. As the LHC moves towards its high-luminosity phase and future high-energy colliders are envisioned, improving the theoretical accuracy of these predictions becomes increasingly important. In this work, we present our ongoing calculation of QCD corrections to polarized W+ Z production with semileptonic decay, targeting NNLO accuracy. We discuss the theoretical and computational challenges of obtaining fully differential predictions, including the treatment of infrared singularities and the generalized analytic evaluation of scalar triangle and a class of box integrals within the Passarino–Veltman framework. We describe our approach to infrared subtraction using the Catani–Seymour dipole formalism and the analytical methods developed to evaluate the relevant loop integrals. We validate the calculation against existing NLO results and present selected differential distributions at NLO, together with preliminary results and prospects for NNLO accuracy.
12. Marek Michalczyk, “Phenomenology and Numerical Analysis of Neutrino Mass Matrix Textures in Extended Flavor Symmetry Models”.
Abstract:
We investigate neutrino mass and mixing patterns shaped by discrete flavor symmetries and specific mass matrix textures. We perform numerical simulations in Mathematica to test the viability of these texture configurations across various theoretical frameworks: 3-flavor Majorana, Hermitian Dirac, non-Hermitian Dirac extensions, as well as 3+1 active-sterile Majorana schemes. By scanning the parameter space, we evaluate the compatibility of these texture models with current global neutrino oscillation data and cosmological bounds.
13. Tomasz Mróz, “Semi-exclusive yy->ll with forward proton tagging at the LHC”.
Abstract:
Studies of semi-exclusive photon-induced dilepton production, γγ → l+ + l−, using forward proton tagging provide an opportunity to explore photon-photon interactions at the Large Hadron Collider (LHC). The ATLAS Forward Proton (AFP) detectors extend the physics capabilities of the ATLAS experiment by detecting protons scattered at small angles and providing complementary kinematic information about the interaction. The poster presents the AFP detector system and the physics motivation for studying dilepton production in events with forward proton tags. An alignment method based on γγ→l+ + l− events is shown. The prospects for measuring semi-exclusive γγ→l+ + l− production with forward proton tagging using LHC Run 3 data are discussed.
14. Nikhil Krishna, “Study of proton charge radius sensitivity in photon-induced dilepton production”.
Abstract:
I plan to present a study of exclusive dilepton production in proton–proton collisions as a probe of the proton charge-radius scale. Using a dipole parametrization of the proton electromagnetic form factor, I will discuss comparisons between the conventional choice of Λ2 parameter (0.71 GeV^2) and benchmark scenarios corresponding to proton charge radii of rp = 0.8751 ± 0.0061, fm and rp = 0.84087 ± 0.00039 fm, representative of the larger CODATA radius and the smaller value obtained from muonic-hydrogen measurements, respectively. I will discuss how the sensitivity to the proton charge radius varies with the dilepton invariant mass and rapidity, with the largest effects observed at high invariant masses
and forward or backward rapidities. I will also present fits to available ATLAS and CMS data, which yield Λ2 = 0.465±0.056,GeV^2, corresponding to an effective proton charge radius of rp = 1.002 ± 0.038 fm within the adopted model. Finally, I will discuss the implications of these results for probing the proton electromagnetic form factor at the LHC and their relevance to the proton-radius puzzle, emphasizing the model dependence of the extracted radius.
15. Paulina Majchrzak, “Top Quarks as Novel Probes of the Quark-Gluon Plasma in ATLAS”.
Abstract:
Measurements of top-quark pair (tt) production in heavy-ion collisions provide a powerful probe of nuclear parton distribution functions and offer unique insights into the properties and temporal evolution of the quark–gluon plasma (QGP). Due to its large mass and extremely short lifetime, the top quark decays before hadronisation, allowing its decay products to traverse and interact with the hot and dense medium. In this work, we review the ATLAS measurements of tt production in Pb+Pb collisions at sNN=5.02 TeV, demonstrating the feasibility of reconstructing top-quark pairs in heavy-ion collisions. In addition, we present a dedicated Monte Carlo study of tt production in Pb+Pb collisions at sNN=5.36 TeV, corresponding to Run 3 conditions, with projections towards the High-Luminosity LHC (HL-LHC). The study considers both dilepton and lepton+jets final states and evaluates the prospects for future measurements of tt production in heavy-ion collisions. These studies highlight the potential of top-quark production as a probe of nuclear effects and demonstrate the prospects for using tt events to investigate the temporal evolution of the QGP, including the possibility of performing a time scan of the medium.