arXiv subjects

Kalina Dimitrova

Publications and source records attributed to Kalina Dimitrova.

7 recordsLinked to original sources

arXiv2026

Searching for the Dark Photon with PADME

The PADME Experiment at Laboratori Nationali di Frascati is designed to search for the Dark Photon, a hypothetical gauge boson responsible for the interaction between the visible and the hidden sector. PADME explores the process of annihilation of beam positrons with the electrons in a fixed target, employing the missing mass technique: in case the annihilation results in the associate production of one visible and one Dark photon, the first can be registered by the experiment's electromagnetic calorimeter and the Dark Photon mass can be reconstructed knowing the beam energy. This paper presents the analysis techniques that are being employed for the PADME data, as well as the background composition and rejection procedure.

hep-ex↗

arXiv2025

Cluster Reconstruction in Electromagnetic Calorimeters Using Machine Learning Methods

Machine-learning-based methods can be developed for the reconstruction of clusters in segmented detectors for high energy physics experiments. Convolutional neural networks with autoencoder architecture trained on labeled data from a simulated dataset reconstruct events by providing information about the hit point and energy of each particle that has entered the detector. The correct reconstruction of the positionand the energy of the incident particles is crucial for the accurate events reconstruction. The presented method shows the ability to reconstruct the impact point within the same segment as the true position and determines the particle energy with good precision. It can be applied in a wide range of cases of event reconstruction where the good separation of overlapping signals plays a key role in the data analysis.

physics.ins-det↗

arXiv2025

Development and Explainability of Models for Machine-Learning-Based Reconstruction of Signals in Particle Detectors

Machine learning methods are being introduced at all stages of data reconstruction and analysis in various high-energy physics experiments. We present the development and application of convolutional neural networks with modified autoencoder architecture for the reconstruction of the pulse arrival time and amplitude in individual scintillating crystals in electromagnetic calorimeters and other detectors. The network performance is discussed as well as the application of xAI methods for further investigation of the algorithm and improvement of the output accuracy.

physics.ins-det↗

arXiv2025

Applicability Evaluation of Selected xAI Methods for Machine Learning Algorithms for Signal Parameters Extraction

Machine learning methods find growing application in the reconstruction and analysis of data in high energy physics experiments. A modified convolutional autoencoder model was employed to identify and reconstruct the pulses from scintillating crystals. The model was further investigated using four xAI methods for deeper understanding of the underlying reconstruction mechanism. The results are discussed in detail, underlining the importance of xAI for knowledge gain and further improvement of the algorithms.

physics.comp-ph↗

arXiv2025

Blind unblinding procedure for the PADME X17 data sample

The PADME experiment at the Frascati DA$\Phi$NE LINAC has performed a search for the hypothetical X17 particle, with a mass of around 17 MeV, by scanning the energy of a positron beam striking a fixed target. The X17 should be produced from the resulting $e^+e^-$ annihilation. Since the expected mass of this particle is only roughly known, data sidebands cannot be clearly defined. Furthermore, the need to keep the analysis blind to potentially sizable signal contributions prevents a clear assessment even of the quality of the data sample in this search. In light of these challenges, this paper presents an innovative strategy adopted by the PADME Collaboration to perform data quality checks without disclosing the X17 sample. Moreover, the procedure designed to eventually unblind the data is described, together with the statistical approach adopted to extract the limits on the coupling between the X17 and the Standard Model.

hep-ex↗

arXiv2023

Status and Prospects of PADME

The Positron Annihilation to Dark Matter Experiment (PADME) was designed and constructed to search for dark photons ($A'$) in the process $e^+e^-\rightarrow\gamma A'$, using the positron beam at the Beam Test Facility (BTF) at the National Laboratories of Frascati (LNF). Since the observation of an anomalous spectra in internal pair creation decays of nuclei seen by the collaboration at the ATOMKI institute, the PADME detector has been modified and a new data-taking run has been undertaken to probe the existance of the so-called ``X17" particle

hep-ex↗

arXiv2022

Using Artificial Intelligence in the Reconstruction of Signals from the PADME Electromagnetic Calorimeter

The PADME apparatus was built at the Frascati National Laboratory of INFN to search for a dark photon ($A'$) produced via the process $e^+ e^- \rightarrow A' \gamma$. The central component of the PADME detector is an electromagnetic calorimeter composed of 616 BGO crystals dedicated to the measurement of the energy and position of the final state photons. The high beam particle multiplicity over a short bunch duration requires reliable identification and measurement of overlapping signals. A regression machine-learning-based algorithm has been developed to disentangle with high efficiency close-in-time events and precisely reconstruct the amplitude of the hits and the time with sub-nanosecond resolution. The performance of the algorithm and the sequence of improvements leading to the achieved results are presented and discussed.

hep-ex↗