9. miniworkshop difrakce, korelací a ultraperiferních srážek

14 Sept 2026, 12:00 → 16 Sept 2026, 15:00 Europe/Prague

ČVUT Děčín

The workshop addresses topics in phenomenology and data analysis techniques used in diffractive processes as well as ultra-peripheral collisions. It will have a colloquial character with emphasis on discussing various tools and approaches used in the field. The majority of talks will be covered by students.

Monday 14 September

16:00 → 17:00 Registration in the hotel

17:00 → 18:30 UPC

Convener: Marek Matas (České vysoké učení technické v Praze)

17:00 Welcome and news

Speaker: Štěpán Mayer

17:20 Some historical remarks on photon-induced interactions for QCD (1/2)

I give a brief overview of the historical evolution of using photons to study the structure of hadrons.
The story starts with the discovery of nuclei, protons and neutrons that lead to the need of a new force.
The touch follows the parallel development of accelerators and the quest to understand the inner most structure of matter.
It discusses at length results from HERA and the development of models to understand those measurments.
It closes with a description of the first results achieved in modern heavy-ion facilities.

Speaker: Jesus Guillermo Contreras

19:00 → 21:00 Dinner

Tuesday 15 September

08:30 → 09:30 Breakfast

09:50 → 12:10 Dark matter and Phenomenology

Convener: Timea Szöllősová

09:50 Dark Matter and how do we know it's there

The nature of dark matter is one of the long-standing problems of modern physics. It is commonly believed that it is formed by a new particle species not yet in the Standard Model. But how can we claim such a specific statement without a direct observation? This will be answered in my talk on the topic.

Speaker: Marek Matas (České vysoké učení technické v Praze)

10:10 The influence of gravitional slingshot on the velocity distribution of dark matter

Dark matter remains one of the greatest mysteries in modern physics. This presentation explores how gravitational manoeuvres with different stellar objects can reshape the dark matter velocity distribution function (VDF). By incorporating realistic VDFs and working in the center-of-mass frame, the simulations uncover new pathways for studying this effect. The talk concludes with implications for direct detection on Earth, offering a fresh perspective on current experimental limits.

Speaker: Adam Červenka

10:30 Introduction to generalized PDFs

A very short introduction to generalizaed parton distributions will be given and it will be shown how it comes together with Balitsky-Kovchegov equation.

Speaker: Jan Čepila (CTU FNSPE)

10:50 Study of hadron structure using angular-dependent Balitsky-Kovchegov equation

While quantum chromodynamics (QCD) allows us to calculate processes governed by the strong nuclear interaction, applying the theory on complex systems, like nucleons, becomes problematic. In order to probe the inner structure of nucleons we use evolution equations. One such equation is the Balitsky-Kovchegov (BK) equation, which describes the evolution of gluon densities with decreasing values of Bjorken$-x$. The BK equation allows us to calculate the scattering amplitude in the high-energy limit of QCD, which can be used to make further predictions about the structure of hadrons at such energies. Although obtaining the full solution to the BK equation is a numerically difficult task, even a partial solution provides accurate predictions about observable quantities, like the $F _2$ structure function.

Speaker: Štěpán Mayer

11:10 Quantum Sensing: What is all the fuss about

Quantum sensing is a rising field in physics. Its applications can have immense consequences for beyond-standard model discoveries as well as for our day-to-day life. This talk will introduce the concept, some of its most impactful consequences, and lay the foundation for the next talk, which will describe the individual devices and discoveries.

Speaker: Marek Matas (České vysoké učení technické v Praze)

11:30 Balitsky-Kovchegov equation at the NLO

The Balitsky-Kovchegov equation at the NLO has been recently solved including the impact parameter dependence. This new results will be presented, explaining the method stabilising the numerical solution and pointing to a potentially problematic part of the evolution kernel.

Speaker: Matěj Vaculčiak (CTU FNSPE)

12:10 → 14:00 Lunch

14:00 → 16:30 Detectors

Convener: Štěpán Mayer

14:00 Quantum Imaging Techniques

This talk will provide an overview of the principles of ghost imaging and quantum radar. These techniques allow detection in harsh environments and through turbulent media thanks to the entangled photon pairs. With this, it is possible to recreate an image with photons which never interacted with the observed object. Recent developments in this area promise revolutionary impacts not only in defence systems, but also in medical imaging and other applications.

Speaker: Timea Szöllősová

14:20 The MuonID project

ALICE 3 is a new detector proposed to operate during the LHC Run 5 and 6. The Muon IDentifier (MID) detector is one of the ALICE 3 subsystems; it is optimized to detect muons down to momenta below 1.5 GeV/c for rapidities |y|<1.3. These muons will be used for the reconstruction of J/ψ vector mesons down to zero transverse momentum at midrapidity. The ALICE 3 tracker large-acceptance will offer access to rare charmonium and exotic states that decay to Jpsi, pions and photons.
The MID detector will be installed outside the superconducting magnet and includes a magnetic steel absorber with variable thickness (70 cm to 38 cm). Given that the particle flux will be of the order of a few Hz/cm^2, plastic scintillator, multi-wire proportional chambers (MWPC), and resistive proportional chambers (RPC) technologies are being considered for the construction of MID.

This talk presents an overview of the detector and its physics goals. Emphasis is made on recent results from a beam test with plastic scintillators and MWPC, the status of the MID simulation, and the plans for the R&D of the MID detector.

Speaker: Solangel Rojas Torres

14:50 Construction of a Forward Diffractive Detector prototype with new light readout

During long shutdown 2, new detectors were installed in ALICE to
achieve better performance in data measurement. Among these detectors was the Fast Interaction Trigger (FIT), which fulfills many roles among other ALICE detectors, such as centrality, luminosity, or vertex determination, to mention a few. Part of this detector is the Forward Diffractive Detector (FDD), a scintillator detector that helps determine key vertex and centrality of collisions.

During Run 4, we expect an increase in the interaction rate provided by the LHC in ALICE. These new conditions motivate the research for improved timing properties of the FDD.
In this thesis, a different approach was investigated with regard to upgrading the detector.

Based on the geometry modification of the scintillator and its materials and replacing key components such as light guides or PMTs, this thesis accomplishes building and testing a new detector prototype to compare with its predecessor.

Speaker: Matěj Tonka

15:10 Adaptive Signal Processing in the LHC Abort Gap Monitor

The Abort Gap Monitor is one of the unseen guardians of the LHC, ensuring that stray protons don’t put the machine at risk. In this talk, I will show how a new adaptive algorithm dynamically controls the detector settings to keep signals stable and safe. I will share what we learned from commissioning and measurements, how the system compares to the legacy monitor, and what challenges remain before it becomes the fully operational standard.

Speaker: Karla Žertová

15:30 Hands on

Can a smartphone camera be used as a radiation detector?
Now a days we all have a smartphone in our pockets, which most of them have a high-quality camera sensor that could be sensitive to radiation. There is one app available that has been seriously tested to turn a your phone in to a geiger counter, lets try out!

http://www.hotray-info.de/html/radioactivity.html
https://www.nature.com/articles/s41598-021-92195-y

Speaker: Solangel Rojas Torres

16:30 → 16:50 Coffee break

16:50 → 18:40 ALICE

Convener: Karla Žertová

16:50 Hadronic interaction studies at the LHC to understand Neutron Stars

Neutron stars are among the most compact and dense objects in the Universe. Their central densities can exceed nuclear density by several times. Under such extreme conditions, hyperons (i.e., baryons containing strange quarks) are expected to be produced for energetic reasons. According to state-of-the-art stellar models, however, the presence of hyperons should significantly reduce the maximum mass of stable neutron stars to values that are incompatible with astronomical observations. This discrepancy is known as the hyperon puzzle. These models, however, rely heavily on our scarce and limited knowledge of the strong interaction between hyperons and nucleons. In this contribution, I will show how data collected by ALICE at the LHC, analyzed using the femtoscopy method, can shed light on hadronic interactions and improve our understanding of neutron star composition.

Speaker: Raffaele Del Grande (Czech Technical University)

17:10 Flow of heavy flavor hadrons in Run 3 data

Collectivity in small systems can be summarized by a simple question : how can a collision that produces on average only a dozen of particles be described so well by hydrodynamics?

In this contribution, we explore this question by the studies of the flow of heavy-flavor hadrons through two-particle long-range correlations using ALICE experiment's forward detectors.

A focus will be done on the specificities of using forward detectors and particularly the Muon Forward Tracker (MFT) in the implementation of this analysis.

Speaker: Alexian Marc Lejeune (Czech Technical University)

17:30 Study of quantum interference using $\rho^0$ photoproduction

The presented study investigates exclusive $\rho^0$ photoproduction in ultraperipheral collisions. Emphasis is placed on quantum interference effects arising from the indistinguishability of the photon source in symmetric heavy-ion collisions. Together with the linear polarisation of the quasi-real photons facilitating the interaction, they produce observable modifications in the transverse momentum spectrum of the vector mesons and azimuthal angle distributions of their decay products. These effects are studied in Pb–Pb collision data at $\sqrt{s_\mathrm{NN}}=5.36$ TeV recorded by the ALICE detector in 2023.

Speaker: Jakub Juračka (FNSPE CTU)

17:50 Incoherent J/ψ production

In quantum chromodynamics, hadrons at high energies reach a dynamic balance between gluon splitting and recombination, a regime referred to as saturation. Diffractive photonuclear production of J/ψ vector mesons offers a powerful probe of the gluon distribution inside hadrons. The Mandelstam variable t, which represents the momentum transfer, provides access to the hadron structure in the impact-parameter plane, with different t ranges sensitive to gluon field dynamics at distinct spatial scales. In this talk, I present a measurement of the energy dependence of incoherent photonuclear J/ψ production off lead ions across several t intervals, measured with ALICE, enabling unprecedented tests of gluon saturation models.

Speakers: Vendulka Fílová (CTU FNSPE), Vendulka Humlová

18:10 Pushing the limits with $\gamma\gamma \to \tau^+ \tau^-$ reactions: one way to search for Beyond Standard Model physics experimentally

The anomalous magnetic moment of the tau lepton ($a_{\tau}$) is a sensitive probe for the search for deviations from the Standard Model predictions and thus for new physics. This study investigates the feasibility of measuring $a_{\tau}$ using ultra-peripheral collisions (UPCs) at the LHC, where photon-photon interactions ($\gamma\gamma \to \tau^+ \tau^-$) produce tau lepton pairs. In this talk, we review the results from the LHC experiments and possible future developments.

Speaker: Roman Lavicka

19:30 → 21:30 Dinner

Wednesday 16 September

08:30 → 09:30 Breakfast

10:00 → 12:00 From the past to the future

Convener: Roman Lavicka

10:00 Some historical remarks on photon-induced interactions for QCD (2/2)

I give a brief overview of the historical evolution of using photons to study the structure of hadrons.
The story starts with the discovery of nuclei, protons and neutrons that lead to the need of a new force.
The touch follows the parallel development of accelerators and the quest to understand the inner most structure of matter.
It discusses at length results from HERA and the development of models to understand those measurments.
It closes with a description of the first results achieved in modern heavy-ion facilities.

Speaker: Jesus Guillermo Contreras

11:00 Quantum Sensing: Where the wild meets the practical

Quantum sensing is a rising field in physics. Its applications can have immense consequences for beyond-standard model discoveries as well as for our day-to-day life. In this talk, we will unravel what all this fuss is about.

Speaker: Marek Matas (České vysoké učení technické v Praze)

12:00 → 14:00 Lunch