The precise reconstruction of properties of photons and electrons in modern high energy physics detectors, such as the CMS or ATLAS experiments, plays a crucial role in numerous physics results. Conventional geometrical algorithms are used to reconstruct the energy and position of these particles from the showers they induce in the electromagnetic calorimeter. Despite their accuracy and efficiency, these methods still suffer from several limitations, such as low-energy background and limited capacity to reconstruct close-by particles. This paper introduces an innovative machine-learning technique to measure the energy and position of photons and electrons based on convolutional and graph neural networks, taking the geometry of the CMS electromagnetic calorimeter as an example. The developed network demonstrates a significant improvement in resolution both for photon energy and position predictions compared to the algorithm used in CMS. Notably, one of the main advantages of this new approach is its ability to better distinguish between multiple close-by electromagnetic showers.

France

Polina Simkina

Fabrice Couderc

Julie Malclès

Mehmet Sahin

Reconstruction of electromagnetic showers in calorimeters using Deep Learning

Data-driven methods are widely used to overcome shortcomings of Monte Carlo simulations (lack of statistics, mismodeling of processes, etc.) in experimental high energy physics. A precise description of background processes is crucial to reach the optimal sensitivity for a measurement. However, the selection of the control region used to describe the background process in a region of interest biases the distribution of some physics observables, rendering the use of such observables impossible in a physics analysis. Rather than discarding these events and/or observables, we propose a novel method to generate physics objects compatible with the region of interest and properly describing the correlations with the rest of the event properties. We use a generative adversarial network (GAN) for this task, as GANs are among the best generator models for various applications. We illustrate the method by generating a new misidentified photon for the  $$\gamma + \textrm{jets}$$  <math> <mrow> <mi>γ</mi> <mo>+</mo> <mtext>jets</mtext> </mrow> </math>   background of the  $$\textrm{H}\rightarrow \gamma \gamma $$  <math> <mrow> <mtext>H</mtext> <mo>→</mo> <mi>γ</mi> <mi>γ</mi> </mrow> </math>   analysis at the CERN LHC, and demonstrate that this GAN generator is able to produce a coherent object correlated with the different properties of the rest of the event.

Victor Lohezic

Julie Malcles

Data driven background estimation in HEP using generative adversarial networks

Recently proposed Future Circular Collider-based muon–proton colliders will allow for investigating lepton–hadron interactions at the highest center-of-mass energy. In this study, we investigate the potential of these colliders for a four-fermion contact interactions search. Regarding the constructive and destructive interferences of contact interactions, we estimated discovery, observation, and exclusion limits on the compositeness scale for the left–left, right–right, left–right, and right–left helicity structures. In this regard, we obtained compositeness scales for the left–left helicity structure at $\sqrt {s} = 63.2$ TeV FCC-based $\mu p$ collider with the 100 fb$^{-1}$ integrated luminosity as $225.7\pm 1.9$% TeV (discovery), $269.0\pm 2.0$% TeV (observation), and $311.3\pm 2.1$% TeV (exclusion). This study’s findings show that the FCC-based $\mu p$ colliders have great potential for investigating four-fermion contact interactions.

Türkiye

Gural Aydin

Yusuf Oguzhan Günaydin

Mehmet Türker Tarakcioglu

Saleh Sultansoy

Contact Interactions at Future Circular Collider Based Muon–Proton Colliders

Resonant production of excited <math id="M4"><mrow><mi>u</mi></mrow></math> and <math id="M5"><mrow><mi>d</mi></mrow></math> quarks at the Future Circular Collider and Super Proton-Proton Collider has been researched. Dominant jet-jet decay mode has been considered. It is shown that FCC and SppC have great potential for discovery of excited <math id="M6"><mrow><mi>u</mi></mrow></math> (<math id="M7"><mrow><mi>d</mi></mrow></math>) quark: up to 44.1 (36.3) and 58.4 (47.8) TeV masses, respectively. For degenerate case (<math id="M8"><mrow><msub><mrow><mi>M</mi></mrow><mrow><msup><mrow><mi>u</mi></mrow><mrow><mo>⋆</mo></mrow></msup></mrow></msub></mrow></math> = <math id="M9"><mrow><msub><mrow><mi>M</mi></mrow><mrow><msup><mrow><mi>d</mi></mrow><mrow><mo>⋆</mo></mrow></msup></mrow></msub></mrow></math>), these values are 45.9 and 60.9 TeV, respectively. This discovery will also afford an opportunity to determine the compositeness scale up to multi-PeV level.

Ahmet Nuri Akay

Azerbaijan

Search for Excited And Quarks in Dijet Final States at Future Colliders

Several Beyond the Standard Model theories proposed that fermions might have composite substructure. The existence of excited quarks is going to be the noticeable proof for the compositeness of Standard Model fermions. For this reason, excited quarks have been investigated by phenomenological and experimental high-energy physicists at various collider options for the last few decades. The Future Circular Collider (FCC) has been recently planned as particle accelerator to be established at CERN. Beside the $\sqrt{s}=100$~TeV proton--proton collisions, the FCC includes electron--positron and electron--proton collision options. Construction of linear $e^- e^+$ colliders (or dedicated e-linac) tangential to the FCC will afford an opportunity to handle multi-TeV $ep$ and $\gamma p$ collisions. In this respect, we executed a simulation of the resonance production of the excited $u$ quark at the FCC-based $\gamma p$ colliders with choosing both the polarized and unpolarized photon beams. The findings revealed that the chirality structure of the $q^*$--$q$--$\gamma$ vertex can be determined by the photon beam polarization. The attainable mass limits of the excited $u$ quark reached the highest values when the polarized photon beam was chosen. In addition, the ultimate compositeness scale values can be handled by appropriate choice of the photon beam polarization.