arXiv subjects

Michal Silarski

Publications and source records attributed to Michal Silarski.

9 recordsLinked to original sources

arXiv2026

Kaonic Copper and Fluorine Absolute Yields Measurement with a CZT-based Detection System at DA$Φ$NE

\noindent In this work, new measurements of absolute X-ray yields for several transitions in kaonic copper and, for the first time, in kaonic fluorine are reported. The data were collected by the SIDDHARTA-2 collaboration at the DA$Φ$NE collider using a novel room-temperature Cadmium Zinc Telluride (CZT) detection system. Detection efficiencies were evaluated through a dedicated Geant4 Monte Carlo simulation of the full experimental setup, enabling the extraction of absolute yields per stopped kaon. \noindent The measured yields exhibit a systematic dependence on the principal quantum number, reflecting the interplay between radiative transitions, Auger de-excitation, and strong-interaction-induced nuclear capture. In kaonic fluorine, a suppression of the 4$\to$3 transition yield relative to higher-n transitions is observed, providing evidence for the onset of strong-interaction effects already at the $n=4$ level. From this behaviour, a conservative lower limit on the corresponding strong-interaction width is derived. \noindent These results provide new quantitative constraints for cascade models of exotic atoms and extend experimental access to intermediate atomic levels where strong-interaction effects are not directly observable via level shifts and widths. They also establish CZT-based detection as a powerful and versatile approach for high-resolution X-ray spectroscopy of kaonic atoms in collider environments.

nucl-ex↗

arXiv2026

CZT Detectors for kaonic atoms spectroscopy

Cadmium zinc telluride (CZT) detectors offer excellent room-temperature energy resolution, making them well suited for X- and $γ$-ray spectroscopy in challenging environments. Within the SIDDHARTA-2 program at the DA$Φ$NE collider, a new CZT-based detection system has been developed to enable precision measurements of kaonic atom transitions in the intermediate mass range. In this work, we report the results of a calibration campaign performed with the collider operating, aimed at assessing the detector performance. A dedicated setup, including an array of quasi-hemispherical CZT sensors and a $^{152}$Eu source, was used to characterize the spectral response. The reconstructed emission lines were fitted with a model accounting for Gaussian response and incomplete charge recollection tails, and the detector linearity was evaluated by comparing the measured peak positions with their nominal energies. The results demonstrate that the CZT detector exhibits excellent linearity and stable operation with the collider on, confirming its suitability for future kaonic-atom spectroscopy at DA$Φ$NE.

physics.ins-det↗

arXiv2025

Time-based Selection of Kaonic Atom X-ray Events with Quasi-Hemispherical CZT Detectors at the DAFNE collider

This work presents the results of a time-based event selection for searching X-ray signals from kaonic atom X-ray transition using a single quasi-hemispherical Cadmium-Zinc-Telluride (CZT) detector at the DA$Φ$NE collider. To mitigate the high background level in the measured X-ray spectrum, a dedicated event selection strategy was developed, exploiting the precise timing correlation between e+e- collisions and detector signals. This approach enabled, for the first time, the observation of two characteristic X-ray transitions from kaonic aluminum atoms using a CZT detector: for the 5-4 transition at 50~keV, 362~$\pm$~41~(stat.)~$\pm$~20~(sys.) signal events over 1698~$\pm$~197~(stat.)~$\pm$~25~(sys.) background events in 5$σ$ were observed, with a resolution of 9.2\%~FWHM; for the 4-3 transition at 106~keV, 295~$\pm$~50~(stat.)~$\pm$~20~(sys.) signal events over 2939~$\pm$~500~(stat.)~$\pm$~16~(sys.) background events in 5$σ$ were measured, with a resolution of 6.6 ~FWHM. A strong background suppression of approximately 95\% of the triggered data was achieved through this time-based selection. The demonstrated timing capability of the CZT detector proved highly effective in isolating time-correlated events within an 80 ns window, setting an important benchmark for the application of these semiconductors in timing-based X-ray spectroscopy. These results highlight the potential of CZT-based detection systems for future precision measurements in high-radiation environments, paving the way for compact, room-temperature X-ray and $γ$-ray spectrometers in fundamental physics and beyond.

physics.ins-det↗

arXiv2024

Intermediate Mass Kaonic Atoms at DA$Φ$NE

The SIDDHARTA-2 collaboration aims to measure for the first time the shift and width induced on the $1s$ level of kaonic deuterium by the strong interaction. In the preliminary phase to the experiment, a test run using a Helium-4 target was performed to optimize the performance of the full experimental apparatus. This preliminary study highlighted the possibility to measure transition lines coming from intermediate mass kaonic atoms, such as kaonic carbon and kaonic aluminum. In order to measure transitions where strong interaction is manifesting at higher energies, out of the energy range of the SIDDHARTA-2 apparatus, the collaboration is testing a new detector system which exploits a novel compound semiconductor, the Cadmium Zinc Telluride. Tests are now running at DA$Φ$NE to study the performance of this detector, exploring the possibility to build a dedicated setup.

nucl-ex↗

arXiv2024

First Linearity and Stability Characterization for CZT Detection System in a e$^+$e$^-$ Collider Environment

The SIDDHARTA-2 collaboration built a new cadmium-zinc-telluride (CZT, CdZnTe)-based X-ray detection system, used for the first time in the DA$Φ$NE electron-positron collider at INFN-LNF. The aim of this work is to show that these detectors present optimal long- and short-term linearity and stability to perform precise spectroscopic measurements in a collider environment. The spectra used as references for calibration are reported, and the results about the linearity and stability studies are presented. It is also discussed and showed what is the proper function to describe all the effects that alter the Gaussian shape in semiconductors, particularly evident in the CZT case. Good residuals and resolutions were obtained for all the calibrations. In a test run with the source and the collider beam on, it was demonstrated that the calibrations made with beam off are optimal also when the beam is on, and the actual systematics in a physics run were estimated. These promising results show the potentialities of this detector in the high rate environment of a particle collider, and pave the way for the use of CZT detectors in kaonic atoms researches and in accelerators, with applications for particle and nuclear physics.

physics.ins-det↗

arXiv2018

Latest studies on the reaction e+ e- --> K + K- gamma

Recent theoretical studies of the e+ e- --> K + K- gamma process are described. Three main reaction mechanisms are considered: the initial state radiation, the final state radiation and the strong interaction between the outgoing K+ K- mesons. The K+ K- effective mass distributions are derived for three different models which in past have been used for a description of the e+ e- --> pi+ pi- gamma data. Also the numerical results for the angular photon and kaon distributions are presented. A new model of the e+ e- --> M_1 M_2 gamma reactions is outlined which can serve for multichannel analyses of the radiative processes with a production of two pseudoscalar mesons M_1 and M_2.

hep-ph↗

arXiv2018

Theoretical studies of the reaction e+ e- --> K+ K- gamma

We present studies of the e+ e- --> K+ K- gamma reaction for the e+e- center-of-mass energies close to the phi(1020) meson mass. Different mechanisms leading to the final state are considered. The strong interaction amplitudes of the K+K- pairs in the S-wave are taken into account. In addition, the photon emission in the initial state, the final state radiation effects and all the possible interference terms are included in the transition matrix elements. The K+K- effective mass distributions and the angular dependence of the reaction cross-section are calculated.

hep-ph↗

arXiv2009

Study of the Low Energy Dynamics in the ppK+K- System with the Cosy-11 Magnetic Spectrometer

The near threshold production of K+K- pairs in proton-proton collisions has been investigated at the cooler synchrotron COSY below and above the threshold for the ϕmeson production. The experimental excitation function determined for the pp-->ppK+K- reaction differs from theoretical expectations including proton-proton final state interaction. The discrepancy may be assigned to the influence of K+K- or pK interaction. In this article we present distributions of the cross section for the pp-->ppK+K- reaction as a function of the invariant masses of two and three particle subsystems at excess energies of Q=10 MeV and 28 MeV.

hep-ph↗

arXiv2008

Analysis of the differential cross sections for the reaction pp --> ppK+K- in view of the K+K- interaction

Measurements of the pp-->ppK+K- reaction, performed with the experiment COSY-11 at the Cooler Synchrotron COSY, show a significant difference between the obtained excitation function and theoretical expectations including pp-FSI >. The discrepancy may be assigned to the influence of K+K- or K-p interaction. This interaction should manifest itself in the distributions of the differential cross section. This thesis presents an analysis of event distributions as a function of the invariant masses of two particle subsystems. In particular in the analysis two generalizations of the Dalitz plot proposed by Goldhaber and Nyborg are used. The present Investigations are based on the experimental data determined by the COSY-11 collaboration from two measurements at excess energies of Q = 10 MeV and 28 MeV. The experimental distributions are compared to results of Monte Carlo simulations generated with various parameters of the K+K- and K-p interaction. The values of the K+K- scattering length, extracted from two data sets for Q = 10 MeV and 28 MeV amount to: a_K+K- = (11 +- 8) + i(0 +- 6) fm for Q = 10 MeV, and a_K+K- = (0.2 +-0.2) + i(0.0 +- 0.5) fm for Q = 28 MeV, Due to the low statistics, the extracted values have large uncertainties and are consistent with very low values of the real and imaginary part of the scattering length.

hep-ex↗