Strange exotic atoms, in which a kaon (or a Sigma minus) replaces an
electron in orbit, offer a precision window into low-energy QCD,
high-precision QED and possible new physics studies.
Recent advances at DAΦNE (SIDDHARTA-2) and J-PARC are enabling
high-accuracy X-ray spectroscopy of kaonic atoms, such as hydrogen,
deuterium, and of many other light-to-heavy exotic atoms.
Proposals...
In the last two decades, great efforts have been made in the development of new-generation X-ray and gamma ray detection systems based on room temperature semiconductor detectors (RTSDs), allowing direct radiation detection and superb room temperature performance. Among RTSDs, cadmium zinc telluride (CdZnTe or CZT) represents the leading detector material: the combination of high atomic number...
Compton cameras (CCs) have gained renewed interest in different areas, including medical applications, such as hadron therapy treatment monitoring [1] or molecular imaging in nuclear medicine [2]. Over the years, CCs have improved in diverse domains [3] and offer advantages due to their high sensitivity, large field of view, compatibility with high-energy radiotracers, lower attenuation, and...
Compton cameras are gamma imaging systems utilized for many applications, from homeland security and environmental radiation activity assessment, to medical imaging. The Compton camera presented in this study consists of segmented scintillators that are read-out by silicon photomultipliers (SiPMs) from two sides. The 4 x 4 x 4 cubical assembly of 3 mm x 3 mm x 3 mm Gadolinium Aluminum Gallium...
We present the experimental validation and performance of a compact single-plane Compton camera that simplifies conventional multi-layer architectures by optically coupling the scatterer and absorber through a light guide, enabling one-sided SiPM readout. A prototype consisting of two 8×8 arrays of GAGG:Ce scintillators (3×3×3 mm³) coupled by 20 mm light guides was constructed and read out...
The measurement of gamma-photons originating in ortho-positronium decay allows for testing of several key concepts in fundamental physics at a scale of table-top experiments. Fundamental discrete symmetries and their combinations can be tested by measuring their angular distributions with respect to the spin direction of the ortho-positronium. Azimuthal correlations of Compton scattered...
Independent dosimetry audits contribute to quality improvement in radiotherapy (RT) practices and enhance consistency of dosimetry between audit participating institutions. Audits can be a valuable tool in detecting systematic errors and determining adequacy of established dosimetry practices. They have an important role in effective reaching of cancer treatment goals and in the safe and...
Increasing healthcare demands and the need for earlier diagnosis are driving the development of PET systems that are both more affordable and more flexible. We present a modular time-of-flight (TOF) PET concept that utilises fast scintillators, state-of-the-art SiPMs, and efficient high-speed readout electronics to achieve high timing precision. Accurate TOF information improves event...
The Dalitz plot for the three-body decay of positronium has so far been only scarcely investigated. Recent advances in precision studies of positronium decays have been enabled by the Jagiellonian Positron Emission Tomograph (J-PET), which utilizes plastic scintillator strips. In this talk, the first experimental Dalitz plot for the ortho-positronium (o-Ps) annihilation into three photons,...
The last twenty years represent the modern era of light kaonic atoms experiments, the precision era. Important progress has been achieved in the modern era, which contributed to a better understanding of the strong interaction in systems containing strangeness at low energies.
Precision spectroscopy of exotic atoms demands the continuous development of cutting-edge radiation detectors, aiming at wide energy range detection capability, ultra-high energy resolution and room temperature operation.
Among these technologies, CZT based detectors and crystal spectrometers represent two excellent possibilities to meet these criteria and have already shown promising...
Surface gamma spectrometry laboratories for environmental radioactivity measurements face challenges in measurements of low-level activities due to the background induced by cosmic radiation, mostly from muons. At the Laboratory for Radioecology of the Ruđer Bošković Institute, a modular home-built cosmic veto system with digital electronics was designed and implemented around an existing high...
Environmental radioactivity laboratories use HPGe detectors enclosed in lead shielding to reduce background radiation and improve the detection of low-intensity peaks. However, once samples are introduced in the measurement setup, the Compton continuum from higher energy peaks can obscure weaker peaks at lower energies.
Traditionally, the detector is surrounded with a large scintillator...
The annihilation of positronium (Ps), a hydrogen-like, unstable atom composed of an electron (e-) and a positron (e+), has been successfully used in basic research to assess the nanostructure properties of organic and inorganic matter, metals, porous materials, and others. In the near future, it may also support oncology diagnostics.
The triplet bound state of positronium (o-Ps) can be...
Conventional Positron Emission Tomography (PET) imaging is based on measurement of energy and coincidence time of back-to-back photons from positron annihilation. The annihilation quanta posses yet another correlation - the orthogonality of their initial polarizations. We developed a demonstrator based on single-layer Compton polarimeters to study the potential of this additional information...
A joint Compton scattering of two maximally entangled photons from an electron-positron annihilation is described by the famous Pryce-Ward statistics. Due to the nature of the entangled state, this statistics is physically (but not mathematically) incompatible with the Klein-Nishina statistics for single photons. We show that these two statistics can be artificially reconciled for purposes of...
Kaonic atoms provide a unique window into studying the strong interaction at threshold, offering key constraints on low-energy QCD in the strangeness sector. In this talk, I will present the latest results from the SIDDHARTA-2 experiment at the DAΦNE collider, which employs high-performance spectroscopic Silicon Drift Detectors (SDDs) to carry out precision X-ray spectroscopy of kaonic atoms....
Kaonic atom spectroscopy provides key observables for investigating low-energy strong interactions in strange systems. In this presentation, I present an overview of the SIDDHARTA-2 collaboration’s activities in the field of kaonic atoms, with a particular focus on the development of a new Cadmium-Zinc-Telluride (CZT) detector system for the study of intermediate-mass kaonic atoms.
This...
