abstract

PET imaging is a key diagnostic tool used clinically to follow and treat disease. While static FDG scans are routine in the clinic, dynamic imaging of disease-specific tracers is important to provide a more precise measure of treatment response. Commercial scanners have limited axial field-of-view and, therefore, we are building a 70 cm long axial FOV TOF PET/CT scanner to enable whole-body dynamic imaging with very high sensitivity. Our scanner is based on detectors with digital SiPMs to provide 300 ps, or better, timing resolution. In this paper, we describe the design and expected performance of this system that will be used for clinical and translational research at the University of Pennsylvania.

abstract

The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET built from plastic scintillators. J-PET prototype consists of 192 detection modules arranged axially in three layers forming a cylindrical diagnostic chamber with the inner diameter of 85 cm and the axial field-of-view of 50 cm. An axial arrangement of long strips of plastic scintillators, their small light attenuation, superior timing properties, and relative ease of the increase of the axial field-of-view opens promising perspectives for the cost effective construction of the whole-body PET scanner, as well as construction of MR and CT compatible PET inserts. Present status of the development of the J-PET tomograph will be presented and discussed.

abstract

The idea of applying the ratio of \(3\gamma \) and \(2\gamma \) positron annihilation rate as a diagnostic indicator in the PET imaging is proposed. It is based on the fact that the \(3\gamma \) annihilation is related to the decay rate of triplet state of positronium atoms produced inside the human body during the PET imaging, and it reflects the size and the concentration of free volumes present in the investigated tissues. The tissues deformation related to the cancerous changes are expected to influence the local value of the \(3\gamma \) fraction.

abstract

Positronium (Ps), the unstable bound state of electron and positron, is a valuable system for neutral antimatter spectroscopic studies and for antihydrogen production. Forming a pulsed beam cold antihydrogen using charge-exchange with the Rydberg Ps is the goal of the AEgIS Collaboration, which aims to measure gravity on neutral antimatter. Recent results achieved in producing, manipulating and studying Ps are summarized. Ps has been first produced with mesoporous silica targets in a reflection geometry. Spectroscopy of Ps \(n=3\) state has been conducted, yielding as a byproduct an independent estimate of the produced Ps temperature. Efficient laser excitation to the Rydberg levels was then achieved, validating the proof-of-concept of AEgIS. Subsequently, production of Ps from a new class of transmission targets was also achieved, opening the possibility for future experiments.

abstract

Results of positron annihilation lifetime measurements of three organic liquids: benzene (C\(_6\)H\(_6\)), cyclohexane (C\(_6\)H\(_{12}\)) and methanol (CH\(_3\)OH) are reported. The lifetime spectra are acquired at several temperatures for non-degassed, degassed and oxygen-saturated samples. The influence of oxygen on each lifetime and intensity component is discussed. Comparison of lifetime components with experiments in gas phase is done.

abstract

Measurements of electron–positron annihilation rays have found applications in both a medical diagnosis and in solid state physics. A similar equipment, located either close to or far from an investigated object, allows to study some quantities either in the real or momentum space — medical or physical investigations, respectively. In the paper, various mathematical methods of computed tomography and their applications to objects having the cubic and hexagonal symmetry are presented, showing some examples of electron–positron momentum densities, which visualize the Bloch states of the electron wave function.

abstract

In this paper, we extend the state-of-the-art filtered backprojection (FBP) method with application of the concept of Total Variation regularization. We compare the performance of the new algorithm with the most common form of regularizing in the FBP image reconstruction via apodizing functions. The methods are validated in terms of cross-correlation coefficient between reconstructed and real image of radioactive tracer distribution using the standard Derenzo-type phantom. We demonstrate that the proposed approach results in higher cross-correlation values with respect to the standard FBP method.

abstract

The use of dual energy computed tomography (DECT) is increasingly considered in particle therapy (PT) to reduce the range of uncertainties attributed to the conversion of X-ray linear attenuation coefficients into relative stopping power (RSP). DECT scanners equipped with clinically available image conversion software can now be found in PT centers. In this work, RSP calculated on the basis of clinical DECT scanner software (syngo.via) was compared to a validated published procedure (Hudobivnik) for calibration and pediatric head phantoms. Based on material inserts, the average difference between RSP values calculated using syngo.via (Hudobivnik) against reference values were 1.0% (0.7%). This difference excludes the lung inserts as the syngo.via method does not provide \(Z_{\rm eff}\) values for CT numbers \(\lt -500\) HU. An analysis of the head phantom showed overall a good agreement with all RSP differences within 1% between the syngo.via and Hudobivnik methods. The use of clinically available syngo.via provides equivalent accuracy as a validated RSP calculation method.

abstract

Proton therapy has rapidly grown in the past thirty years and it has become a superior alternative to conventional radiotherapy for certain clinical indications. Proton therapy offers high dose selectivity due to the protons’ distinct depth dose profile which potentially allows to deliver high dose to the tumor while sparing healthy surrounding tissue. Monte Carlo (MC) simulations, which take explicitly into account all the details in the interaction of particles with human tissues, are considered to be the most reliable tool to reproduce the complexity of mixed-field irradiation in a non-homogeneous environment. The advent of general-purpose programming GPU cards prompted the development of trimmed-down MC-based dose engines, which can significantly reduce the plan recalculation time with respect to standard MC codes on CPU hardware. In this contribution, the GPU-accelerated MC treatment planning system (TPS) Fred developed by the University of Rome is presented (Schiavi et al. , Phys. Med. Biol. (2017)). The current status of the implementation in Fred of the experimentally measured physical beam model data used for treatment planning at the Cyclotron Center Bronowice (CCB) Kraków proton beam therapy centre is reported. Three-dimensional dose distributions of proton pencil beams in a water phantom, i.e. lateral profiles and depth dose distributions, are compared for different beam configurations.

abstract

We present experimental investigation of cross sections for processes crucial in view of prompt-gamma imaging. The prompt-gamma rays were produced from an interaction of a proton beam with different phantom materials composed of carbon, oxygen and hydrogen. The used target setup allowed precise selection of the investigated depth in the phantom. We studied details of the dependence of prompt-gamma yields on beam energy, detection angle and elemental composition of irradiated phantom. The analysis was focused on the discrete transitions with the largest cross sections: 4.44 MeV in \(^{12}\)C and 6.13 MeV in \(^{16}\)O. The results are presented in form of profiles of the prompt-gamma yield as a function of depth. They are compared to calculations including different cross-section models. Obtained results are in agreement with the model exploiting cross-section data collected from the literature, but the comparison with the TALYS model shows discrepancies. In the latest experiment, special attention was paid to the shape of the distal fall-off. The width of that fall-off is directly linked to the resolution of prompt-gamma based methods of range verification. Preliminary results on the beam-energy dependence of this quantity are presented.

abstract

Single Photon Emission Computed Tomography (SPECT) is at present one of the major techniques for non-invasive diagnostics in nuclear medicine. Almost the whole clinical routine is based on collimated cameras, originally proposed by Anger. The presence of mechanical collimation limits detection efficiency and energy acceptance. The application of Compton cameras for SPECT could allow to overcome these limitations. In this study, we propose to compare our Compton camera prototype to a commercial Anger device, the GE Healthcare Infinia system, through Monte Carlo simulations (GATE v7.1 and Geant4 v9.6 respectively). Given the possible introduction of new radioemitters at higher energies allowed by the Compton camera detection principle, the detectors are exposed to point-like sources at increasing gamma energies. The detector performances are studied in terms of radial event distribution, detection efficiency and final image, obtained by gamma transmission analysis for the Anger system, and with an iterative LM-MLEM algorithm for the Compton reconstruction. Preliminary results show for the Compton camera a detection efficiency increased of a factor greater than an order of magnitude, associated with an enhanced spatial resolution for high energies. We then discuss the proven advantages of the Compton camera application with particular focus on dose delivered to the patient, examination time and spatial uncertainties.

abstract

Various biological systems are characterized with different radiation sensitivity to different damaging factors. The basic idea justified in theoretical and experimental models confirms “the target theory”. The principle of a target theory assumes that radiation sensitivity correlates with chemical and morphological characteristics, the size and type of the sensitive structure. The target of enzymes was shown to be the entire molecule, for viruses or bacteria, the total deoxy- or ribonucleic acids (DNA or RNA) strands, in the higher Eukaryotic cells, the specific of arrangements of DNA within chromosomes and epigenetic modifications reinforce the system in the target complexity. In this paper, we would like to introduce the new theoretical and experimental framework for understanding the complexity of biological systems and what we currently know about the genetic and epigenetic mechanisms regulating metabolic and genetic response to radiation on the cellular level, highlighting the differences between a normal and a cancer cell.

abstract

NanOx, a new biophysical model developed to predict cell survival probability in the context of hadrontherapy, will be presented in the following. The model takes into account the fully stochastic nature of ionizing radiation by considering dose fluctuations both at nanometric and micrometric scales, and introduces the concept of chemical specific energy. The latter represents the induction of cell death by “non-local” events as the accumulation of cellular oxidative stress or sub-lethal lesions induced by reactive chemical species. Such “non-local” events are complementary to “local” events, which take place at a very localized scale and are considered as lethal since they can singly cause cell death. NanOx predictions for V79, CHO-K1 and HSG cell lines irradiated by carbon ions are in a good agreement with the experimental data. The model is able to describe the effectiveness of ions, including the overkill effect at high LET values via the fit of a limited set of parameters. Moreover, the typical shoulder in cell survival curves is reproduced owing to the introduction of the chemical specific energy which varies with LET.

abstract

The development of a liquid xenon Compton camera called XEMIS2 (XEnon Medical Imaging System) is a step forward to a new type of medical imaging based on the use of \(^{44}\)Sc radionuclide emitting two annihilation \(\gamma \) rays and a third high energy \(\gamma \) ray simultaneously. The single phase TPC (Time Projection Chamber) under construction, containing nearly 200 kg of xenon, is designed to measure most of the Compton interactions in the active area with a sub-millimetre position resolution and a good energy resolution of 4% on 511 keV photopeak. The intersection of the Compton cone surface from the third \(\gamma \) ray with the line of response from the two annihilation \(\gamma \) rays allows to localize the radionuclide with a precision (FWHM) of about 1 cm along this line. The large field of view of such a liquid xenon camera combined with the 3\(\gamma \) imaging technique will provide a good quality image while keeping the injected activity at a very low level. XEMIS2 will be installed in the Nantes University Hospital in order to demonstrate its capability to image small animals injected with a low activity of only 20 kBq in 20 mn acquisition time. To achieve this goal, a precise measurement of the ionization signal is provided by a pixelized anode, shielded by a Frisch Grid and read out by a low noise front-end electronics. In addition, new cryogenic and purification subsystems have been tested, allowing safe recovery of xenon in liquid phase at flow rates of about 1 ton per hour.

abstract

The neutron activation technique is utilized to determine activation cross-section values for neutron-induced reactions on Lu, Tb, Dy, Er and Yb isotopes with application of in-home designed and manufactured neutron generator NG-300 and AMANDE facility within 3.5\(\div \)14.7 MeV energy range of incident neutrons. Observation of the dineutron in the output channel of nuclear reaction on Tb is discussed. The cross-section estimate for the reaction with a dineutron escape for 6.85 MeV equals 75 \(\pm \) 30 mb and is presented for the first time.

abstract

The Neutron Activation Analysis (NAA) plays an exceptional role in the modern nuclear engineering, especially in detection of hazardous substances. However, in the aquatic environment, there are still many problems to be solved for effective usage of this technique. We present the status of SABAT (Stoichiometry Analysis By Activation Techniques), one of the projects aiming at construction of an underwater device for non-invasive threat detection based on the NAA.

abstract

Nowadays, the current threat of international terrorism is set to a severe level, demanding worldwide enhanced security. Radioactive materials that could be fashioned into a radiation dispersal device typically emit gamma rays, while fissile materials such as uranium and plutonium emit both neutrons and gamma rays via spontaneous or induced fission. Therefore, the detection and identification of hazardous materials has become increasingly important. We present the results of Geant4 Monte Carlo simulation of an active neutron interrogation system based on highly segmented neutron/gamma-ray detector and pulsed neutron generator. This system is capable of detecting and imaging radioactive and special nuclear materials, explosives and drugs. The segmented scintillation detector works as a scatter camera, allowing selection of a gamma-ray events that undergo multiple interaction in detector blocks for radioactive source localization. The detector consists of blocks made of plastic scintillator which provide scattering and blocks of CsI, used as an absorber, which has to be efficient to detect the characteristic gamma radiation for the identification. Because of this imaging capability, background events can be significantly rejected, decreasing the number of events required for high-confidence detection and thereby greatly improving its sensitivity. A scatter imager for the detection of shielded radioactive materials has been conceptualized, simulated, and refined to maximize sensitivity while minimizing cost.

abstract

The possibility of obtaining thermal/epithermal neutron beams using external protons from cyclotron C18/18 is studied based on Geant4 simulations. The design and optimization characteristic of the Beam Shaping Assembly (BSA) for neutron flux from thick \(^9\)Be target was studied with Geant4 program. To obtain the thermal/epithermal neutron beam, appropriate materials for moderator and reflector with optimal thicknesses were determined. In this model of the Geant4 simulation, two programs for physics lists were used. These are one of the most important parts of the creation the correct model, which will be as close as possible to the future experiment. The formed neutron beam will be used not only in fundamental research, but also for practical purposes, in particular, to explore the possibility of applying it in the Boron Neutron Capture Therapy (BNCT).

abstract

The KLOE-2 experiment is presently running at the \(e^+e^-\) DA\(\Phi \)NE \({\mit \Phi }\)-factory of the INFN Laboratori Nazionali di Frascati (LNF) exploiting GEM technology with a cylindrical geometry for the first time in high-energy physics. This novel idea was developed at LNF exploiting kapton properties to build a light and compact tracking system with four concentric cylindrical triple-GEM detectors, inserted around the interaction region and before the inner wall of the pre-existing KLOE Drift Chamber to improve vertex reconstruction capabilities near the interaction region. Single-mask GEM etching, multi-layer XV patterned readout circuit, GASTONE front–end board a custom 64-channel ASIC with digital output, and the Global Interface Board with a configurable FPGA architecture and Gigabit Ethernet, are some of the state-of-the-art solutions of this project. Detector operation, alignment and calibration, never done before for a cylindrical GEM detector, and performance will be reported together with first results from the integrated tracking and vertexing obtained with \(\phi \to \pi ^+\pi ^-\pi ^0\) and \(K_{\rm S} \to \pi ^+\pi ^-\) decays.

abstract

Radiation damage is nowadays the most serious problem in silicon particle detectors placed in the very harsh radiation environment. This problem will be even more pronounced after the LHC Upgrade because of extremely strong particle fluences never encountered before. In this review, a few aspects of radiation damage in silicon trackers are presented. Among them, the change in the silicon lattice and its influence on the detector performance are discussed. Currently applied solutions and the new ideas for future experiments will be also shown. Most of the results presented in this summary were obtained within the RD50 Collaboration

abstract

The VOXES project’s goal is to realize the first prototype of a high-resolution and high-precision X-ray spectrometer for diffused sources, using Highly Annealed Pyrolitic Graphite (HAPG) crystals combined with precision position detectors. The aim is to deliver a cost-effective and easy to handle system having an energy resolution at the level of few eV for X-ray energies from about 2 keV up to tens of keV. There are many applications of the proposed spectrometer, going from fundamental physics (precision measurements of exotic atoms at DA\(\Phi \)NE collider and J-PARC, precision measurement of the \(K^-\) mass solving the existing puzzle, quantum mechanics tests) to synchrotron radiation and applications (X-FEL), astronomy, medicine and industry. Here, the basic concept of such a spectrometer and the first results from a measurement of the characteristic Cu \(K_{\alpha 1}\) and \(K_{\alpha 2}\) X-ray lines are presented.

abstract

We have assembled and tested a system of 2 detector modules containing Lutetium Fine Silicate scintillator pixels in \(4\times 4\) matrix, read out by multi-pixel photon counter arrays with the matching element size. The amplified signals were acquired using fast digitizers and stored for offline analysis. Using two different approaches, we have determined the single crystal relative energy resolution at 511 keV to be 14% and 12%. The coincidence time resolution has been tested using the digital constant fraction triggering and the leading edge method, and the resulting resolutions are 1.6 ns and 0.5 ns, respectively.

abstract

In this paper, we present an elegant and low-invasive method for bio-imaging proteins activity on the molecular level in living cells. Using specially designed genetically encoded CFP-YFP FRET biosensors, proteins activation can be tracked by investigating probes FRET efficiency factor. This system allows to investigate cell physiology on the molecular level in studies of cell migration response to different stimuli, such as electric field.

abstract

Review of papers dealing with muscle functional magnetic resonance imaging (mfMRI) is reported. Advantages of mfMRI and its application in physiotherapy are introduced on the example of the craniocervical region. This noninvasive, relatively new technique allows to study muscle activity on the basis of the MRI signal intensity changes due to increases in the relaxation time (T2) of tissue water (T2 is determined at rest and then in a short time after chosen exercises).

abstract

Samples of uterine leiomyomatis and normal tissues taken from patients after surgery were investigated using the Positron Annihilation Lifetime Spectroscopy (PALS). Significant differences in all PALS parameters between normal and diseased tissues were observed. For all studied patients, it was found that the values of the free annihilation and ortho-positronium lifetime are larger for the tumorous tissues than for the healthy ones. For most of the patients, the intensity of the free annihilation and ortho-positronium annihilation was smaller for the tumorous than for the healthy tissues. For the first time, in this kind of studies, the \(3\gamma \) fraction of positron annihilation was determined to describe changes in the tissue porosity during morphologic alteration.

abstract

One of crucial steps in radiotherapy planning is patient positioning. Cancer radiotherapy requires high precision and specificity throughout whole therapeutic sessions. Due to the various parameter changes, implementing an appropriate treatment plan faces obstacles. While implementing the radiotherapy plan, targeting precisely and intensively areas of cancerous activity at a desired degree of tumor penetration, therefore, sparing underlying tissues from radiation exposure is of very important. The study aims to quantitatively determine the magnitudes of error in anteroposterior, mediolateral and craniocaudal directions, and determine the margin between clinical target volume to planning target volume based on systematic and random errors. Performing patient positioning control routinely before each therapeutic session allows obtaining a comparison of planned geometry and their early correction. Acquiring optimal results requires cooperation between medical personnel and patient. In this paper, the experience in determining margins added to the clinical target volume in different anatomical tumor geometries is presented.

abstract

We present a method and preliminary results of the image reconstruction in the Jagiellonian PET tomograph. Using GATE (Geant4 Application for Tomographic Emission), interactions of the 511 keV photons with a cylindrical detector were generated. Pairs of such photons, flying back-to-back, originate from \(e^+e^-\) annihilations inside a 1 mm spherical source. Spatial and temporal coordinates of hits were smeared using experimental resolutions of the detector. We incorporated the algorithm of the 3D Filtered Back Projection, implemented in the STIR and TomoPy software packages, which differ in approximation methods. Consistent results for the Point Spread Functions of \(\sim 5\div 7\) mm and \(\sim 9\div 20\) mm were obtained, using STIR, for transverse and longitudinal directions, respectively, with no time-of-flight information included.

abstract

Dibaryons are thought to be six-quark objects, potentially constituting a new state of matter. A short review is given about the long-standing search for such objects, from the early days until present, when the first non-trivial dibaryon resonance has been established. Starting from the fifties, the dibaryon search experienced many ups and downs, the dibaryon rush era followed by periods of big frustration and renewed start-ups. The recent first firm observation of a narrow dibaryon resonance gives new impact to this field. Having found one such species raises immediately the question, are there possibly more? Also whether the new state represents a molecule-like object or rather a compact hexaquark system, will be discussed.

abstract

Models based on chiral symmetry predict pentaquarks that have relatively low masses. We briefly review both theoretical and experimental status of exotica in the light sector. Next, we shall show how to extend chiral models to baryons with one heavy quark and show that one expects exotica also in this case. Finally, we interpret recently discovered by the LHCb Collaboration five \({\mit \Omega }^*_c\) resonances in terms of regular and exotic excitations of the ground state \({\mit \Omega }_c\).

abstract

Recent \(\eta \) few-nucleon stochastic variational method calculations that study the onset of \(\eta \)–nuclear binding are reviewed. The energy dependence of the \(\eta N\) subthreshold interaction is treated self-consistently. These calculations suggest that a minimum value Re\(\,a_{\eta N} \approx 1\) fm is needed to bind \(\eta \,^3\)He, whereas \(\eta \,^4\)He binding requires a minimum value Re\(\,a_{\eta N}\approx 0.7\) fm.

abstract

We have developed a theoretical model to evaluate the formation rate of the \(\eta \)-mesic nucleus in the \(d + d\) fusion reaction and show the calculated results. We have compared our results with existing data of the \(d + d \rightarrow \eta + \alpha \).

abstract

We analyze the data on cross sections and asymmetries for the \(pd (dp) \to \eta \,^3\)He reaction close to threshold and look for bound states of the \(\eta \,^3\)He system. Fitting these data in terms of an \(\eta \,^3\)He optical potential, we find a local Breit–Wigner form of the \(\eta \,^3\)He amplitude \(T\) below threshold with a clear peak in \(|T|^2\), which corresponds to an \(\eta \,^3\)He binding of about 0.3 MeV and a width of about 3 MeV. However, this corresponds to a pole in the complex plane above threshold. We also discuss a state found for \(B \bar B^* \rho \) with \(J=3\).

abstract

Among the two-body dynamics of the meson–nucleon systems, the attractive interaction between the eta meson and nucleon is not well-known. A new photoproduction experiment is planned for the determination of the low-energy scattering parameters between the eta meson and nucleon at the Research Center for Electron Photon Science, Tohoku University. The emitted proton is measured at \(0^\circ \) for eta photoproduction on the deuteron at the incident energy of 0.94 GeV, which gives small relative momentum between the eta meson and neutron in the final state to increase rescattering probability. The kinematics is found to have a good resolving power of the scattering length and effective range. In this contribution, the current status of the new experiment is presented.

abstract

We briefly report on the search for \(\eta \)-mesic helium nuclei with WASA-at-COSY detection setup. The description of the experimental method as well as the status of the data analysis of the proton–deuteron reactions are presented.

abstract

We performed a missing-mass spectroscopy experiment of the \(^{12}\)C(\(p,d\)) reaction in order to search for \(\eta ^\prime \)-mesic nuclei. Excitation spectrum of \(^{11}\)C around the \(\eta ^\prime \)-meson production threshold was successfully obtained with a high-statistical sensitivity and sufficiently good energy resolution. Since no peak structure associated with the formation of \(\eta ^\prime \)-mesic nuclei was observed, we set constraints on the formation cross sections of \(\eta ^\prime \)-mesic states and on the \(\eta ^\prime \)–nucleus interaction.

abstract

An experiment for \(\eta '\)-meson photoproduction has been conducted at SPring-8 by utilizing a 2.4 GeV laser-electron photon beam at the LEPS2 beamline. This is an attempt to measure the spectral function of \(\eta '\) mesons propagating in the nuclear medium. For this purpose, an electromagnetic calorimeter, BGOegg, is employed to detect \(\eta '\) decaying into \(\gamma \gamma \) in a nucleus. BGOegg consisting of 1320 BGO crystals exhibits excellent calorimeter performance both in the energy and mass resolutions.

abstract

Tunneling is one of the most bizarre phenomena in quantum mechanics. An attempt to understand it led to the next natural question of how long does a particle need to tunnel a barrier. The latter gave rise to several definitions such as the phase, dwell, Larmor and traversal times among others. A short review of the evolution of these time concepts, followed by an account of experiments involving field-induced tunnel ionization and electron tunneling in a solid state junction is presented here. Whereas the former experiments use sophisticated techniques involving femtosecond laser pulses and determine the tunneling time by mapping the angle of rotation of the field vector to time, like the hands of a watch, the latter provides a simpler method through the measurement of current-voltage characteristics of the junction.

abstract

After reviewing the description of an unstable state in the framework of Lee Hamiltonians (valid both for Quantum Mechanics (QM) and Quantum Field Theory (QFT)), we consider some theoretical aspects of non-exponential decays: the case of two decay channels, the broadening of the energy spectrum at short times, the effect of an imperfect measurement, the link to QFT, and the decay of an unstable moving particle with definite momentum. All the presented effects were not confirmed in experiments, hence they are at the present stage predictions.

abstract

We present a summary of our recent publication concerning the derivation of the extended Casimir–Polder (C–P) dispersive interaction between two neutrons. Dynamical polarizations of the neutrons, recently derived within Chiral Effective Theory, are used for the purpose. An account of the higher frequency/energy behavior of these entities related to the opening of one-pion production channel and the excitation of the \({\mit \Delta }\) resonance are taken into consideration in our derivation of the C–P interaction. The neutron–neutron system in free space is treated in details so are the neutron–wall and the wall–neutron–wall systems. The case of tetraneutron (a 4-neutron system) in a resonant state is then briefly considered. The \(4n\) C–P interaction is evaluated to assess its potential relevance to the ongoing debate concerning the nature of the tetraneutron.

abstract

We analyze properties of unstable systems at rest and in motion.

abstract

The DA\(\Phi \)NE electron–positron collider of the Laboratori Nazionali di Frascati of INFN has made available a unique quality low-energy negatively charged kaons “beam”, which is being used to study the kaon–nucleon/nuclei interactions by the SIDDHARTA-2 experiment and the AMADEUS Collaboration. The dynamics of the strong interaction processes in the non-perturbative regime is approached by lattice calculations and effective field theories (ChPT) which are still lacking experimental results in the low-energy regime, fundamental for their good understanding. The studies of kaonic atoms and of the kaonic nuclear processes performed by SIDDHARTA-2 and AMADEUS play in this context a key-role.

abstract

Both the FINUDA and AMADEUS experiments evidenced a low \({\mit \Sigma }^+\) momentum component when investigating \({\mit \Sigma }^+ \pi ^-\) pairs produced in \(K^-\) nuclear capture. This component is interpreted as a consequence of the Gamov state formation, with the hyperon trapped in the Coulomb field of the residual nucleus. Description of such states and their participation in the capture reaction is presented. Some consequences are indicated.

abstract

Recently, a peak structure was observed near the \(K^{-} p p\) threshold in the in-flight \({}^{3} {\rm He} (K^{-}, \, {\mit \Lambda } p) n\) reaction of the E15 experiment at J-PARC, which could be a signal of a \(\bar {K} N N\) bound state. In order to investigate what is the origin of this peak, we calculate the cross section of this reaction, in particular based on the scenario that the \(\bar {K} N N\) bound state is indeed generated and decays into \({\mit \Lambda } p\). We find that the numerical result of the \({\mit \Lambda } p\) invariant-mass spectrum in the \(\bar {K} N N\) bound scenario is consistent with the J-PARC E15 data.

abstract

The AMADEUS experiment deals with the investigation of the low-energy kaon–nuclei hadronic interaction at the DA\(\Phi \)NE collider at LNF-INFN, which is fundamental to solve longstanding questions in the non-perturbative strangeness QCD sector. AMADEUS step 0 consisted in the reanalysis of the 2004/2005 KLOE data, exploiting \(K^-\) absorptions in H, \({}^4\)He, \({}^9\)Be and \({}^{12}\)C, leading to the first invariant mass spectroscopy study with very low-momentum (100 MeV) in-flight K\(^-\) captures. With AMADEUS step 1, a dedicated pure carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest \(K^-\) nuclear interaction. The results obtained in the analyses of the hyperon–pion correlated events, searching for the resonant shapes of \(Y\) states, will be described.

abstract

The capture of \(K^-\) mesons on nucleons bound in nuclei offers a chance to study the \({\mit \Sigma } \pi \) pairs below the kinematic threshold of the \(\bar {K}N\) systems. Various hyperon–pion charged combination are presently under investigation by AMADEUS. These data allow to test both isospin \(0\) and \(1\) amplitudes giving the possibility to detect the structure of resonant \({\mit \Lambda }(1405)\) state. Contrasted against similar electro-production data, they allow to detect changes of \({\mit \Lambda }(1405)\) in nuclear media. Expected spectra and their uncertainties are calculated.

abstract

Production of hadronic hydrogen-like atoms at high-energy collisions and method of their observation are considered. Main results of the DIRAC experiment on observation and lifetime measurement of atoms formed by pairs of charged pion–pion and pion–kaon are presented.

abstract

We give an introduction to the exciting physics of the ELENA facility at CERN.

abstract

Hadron properties and interactions are emergent from QCD. Atomic and condensed matter physics are emergent from QED. Could the local gauge symmetries of particle physics also be emergent? We give an introduction to this question and recent ideas connecting it to the stability of the Standard Model Higgs vacuum and the value of the cosmological constant.

abstract

Pairs of pseudoscalar neutral mesons from decays of vector resonances are studied as bipartite systems in the framework of density operator. Time-dependent quantum entanglement is quantified in terms of the entanglement entropy and these dependences are demonstrated on data on correlated pairs of \(K\) and \(B\) mesons, as measured by the KLOE and Belle experiments. Another interesting characteristics of such bipartite systems are moments of the CP distributions. These moments are directly measurable and they appear to be very sensitive to the initial degree of entanglement of a pair.

abstract

A direct test of the T, CP and CPT symmetries in the neutral kaon system can be performed comparing a transition process \(i \rightarrow f\) to its symmetry conjugated one. The exchange of in and out states required for genuine tests involving the time-reversal T can be performed exploiting the entanglement of the kaon pair produced at a \(\phi \)-factory. In particular, using this method, it would be possible to perform a very clean and fully robust CPT test, which might shed light on possible new CPT-violating mechanisms. It is being implemented with the KLOE-2 experiment at the DA\(\Phi \)NE facility in Frascati, where a statistical sensitivity of \(\mathcal {O}(10^{-3})\) on the newly proposed observable quantities could be reached.

abstract

An experiment to test the Time Reversal Invariance is planned at the synchrotron COSY-Jülich (TRIC). TRIC is constructed as a transmission experiment at the storage ring which will use a genuine T-odd P-even null observable available in double polarised \(pd\) scattering. The goal of the experiment is to improve the present limit on a T-odd P-even interaction by at least one order of magnitude. In this contribution, the status of the preparatory work, advantages of the experiment, and a new formalism which links beam current measurement resolution and precision of the experiment are reported.

abstract

The paper confronts two perspectives on the asymmetry of time: a philosophical and a physical one. From the philosophical perspective, time has fundamental asymmetries which together form an asymmetry of time: there seems to exist something like a distinguished Now moving toward the future; we have many traces of the past — both in our memory and in the external world — but no traces of the future; events from the past influence those from the future, but we have no evidence of backward causation; the future seems to be open and we definitely cannot change the past. Because we believe in physics as a fundamental theory describing the world, we expect that physics should explain all of these asymmetries. However, the rub lies in the fact that physics, as it is known at present, is unable to explain these asymmetries. This means that physical processes such as the entropy increase, the expansion of the Universe or those in which weak interactions are involved only form asymmetries in time, that is, they just represent some asymmetrical physical processes in time. The way out of this difficulty can be sought in two directions: either we can look for a fundamental temporally irreversible law of nature which would be able to explain the temporal asymmetries of the world or we should look for the solution of the issue at hand outside of physics, that is, in metaphysics. The paper shows the difficulties of both directions of research.

abstract

Belief in slight Lorentz symmetry violation at available energies is an imaginable part of belief in radically disparate physics near the Planck energy. As long as the effective field theory comprising new physics is formulated in flat spacetime, the description of hypothetical Lorentz symmetry violation within its formalism is consistent and tenable. If gravitation is introduced into the effective theory in the form of curved manifolds subject to Einstein field equations, the formalism of the symmetry violation encounters severe troubles. Either the dynamics of fundamental physical fields becomes inconsistent, or one is forced to accept existence of a large number of new species of fundamental matter beyond the Standard Model.

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Entanglement of the three-photon from the decay of ortho-positronium is re-analyzed. We use the full three-body phase space to write down the entangled states classified according to the spin directions of the ortho-positronium. Even in the case when the spin is perpendicular to the decay plane, we find non-negligible phases entering the entangled state. This has not been noticed before. We advocate a fixed quantization axis of the spin for the sake of generality. A brief discussion of a three-dimensional formalism for photons, including correlations, versus a two-dimensional one is given.

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The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for medical imaging of the whole human body as well as for physics studies involving detection of electron–positron annihilation into photons. J-PET has high angular and time resolution, and allows for measurement of spin of the positronium and the momenta and polarization vectors of annihilation quanta. In this article, we present the potential of the J-PET system for the background rejection in the decays of positronium atoms.

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Large value of \(\theta _{13}\) angle, one of the parameters of neutrino oscillations measured precisely by the reactor experiments, opened a possibility to probe CP-violating phase in neutrino oscillations. The review of the most recent experimental results on the CP violation search in the oscillations of the accelerator neutrinos is presented. Results from the two world-leading long-baseline experiments: T2K and NOvA are discussed. T2K reported its updated results using simultaneous fit to \(\nu _e\) appearance and \(\nu _{\mu }\) disappearance channels both for neutrino- and antineutrino-mode beam. T2K provides the 90% C.L. region for \(\delta _{\rm CP}\) phase as well as excludes the hypothesis of CP conservation (\(\delta _{\rm CP}=0,\pi \)) at 90% confidence level. The article also briefly discusses first results from the NOvA experiment related to the CP phase measurement as well as the prospects for the CP violation search in the planned accelerator neutrino experiments.

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The KLOE-2 detector records decays of quantum-entangled pairs of neutral kaons produced in decays of \(\phi \) mesons provided by the DA\(\Phi \)NE accelerator at the Laboratori Nazionali di Frascati, Italy. This system allows for a broad range of studies of fundamental discrete symmetries including tests which are only feasible with entangled neutral mesons. This work reports on the Lorentz non-invariance and CPT violation searches with the \(\phi \to K_{\rm S} K_{\rm L}\to \pi ^+\pi ^-\pi ^+\pi ^-\) process in the framework of the Standard Model Extension. Moreover, status and results of quantum coherence tests with the same process are discussed. Finally, the status of ongoing direct tests of T and CPT in neutral kaon transitions is presented. For each of the reported studies, perspectives are discussed for the KLOE-2 experiment, which is presently taking data.

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The goal of the P349 experiment is to test whether the antiproton production process can be itself a source of antiproton polarization. In this article, we present the motivation and details of the performed measurement. We report on the status of the analysis focusing mainly on calibration of the drift chambers and 3d track reconstruction.

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The LHCb is a single arm forward spectrometer designed to study heavy-flavour physics at the LHC. Its very precise tracking and excellent particle identification play currently a major role in providing the world-best measurements of the Unitary Triangle parameters. In this paper, selected results of the Cabibbo–Kobayashi–Maskawa (CKM) angle \(\gamma \) measurements, with special attention for \(B \to DK\) decays family, obtained at the LHCb, are presented.

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We study the elastic nucleon–deuteron (\(Nd\)) scattering process at the incoming nucleon laboratory energy \(E=65\) MeV working within the formalism of Faddeev equations. We employ, for the first time in the elastic \(Nd\) scattering, the OPE-Gaussian nucleon–nucleon (\(NN\)) potential and confirm its high quality by comparing our predictions for the differential cross section with results based on the AV18 potential as well as with available data. We also estimate the theoretical uncertainty of this observable originating from uncertainties of the OPE-Gaussian model parameters. We find the relative uncertainties to be smaller than 0.8% for the differential cross section. The correlations between various parameters of the OPE-Gaussian are also shown.