abstract

We have investigated phenomenological aspects of kaon photoproduction in three different extreme kinematics. The first kinematics of interest is the threshold region. At the threshold, we have investigated the convergence of kaon photoproduction amplitude by expanding the square of the amplitude in terms of the ratio \(m_K/m\), where \(m_K\) is the mass of kaon and \(m\) is the averaged mass of nucleon and \({\mit \Lambda }\) hyperon. The amplitude is calculated from the appropriate Feynman diagrams by using the pseudovector theory. The contact diagram as a consequence of the PCAC hypothesis is also taken into account in the amplitude. Our finding indicates that the convergence can only be achieved if the amplitude was expanded up to the at least \(12^{\mathrm {th}}\) order. As a consequence, applications of some theoretical calculations based on the expansion of the scattering amplitude, such as the Low Energy Theorem or Soft Kaon Approximation, cannot be easily managed in kaon photoproduction. The second kinematics is the forward region, where we could assume only \(t\)-channel contributes to the process. Here, we have investigated the effect of amplitude expansion on the extraction of the coupling constants \(g_{K^+{\mit \Lambda } p}\) and \(g^{\mathrm {V}}_{K_1^+{\mit \Lambda } p}\). The last kinematics is the backward region, where we have also assumed that only \(u\)-channel survives and we could extract the leading coupling constants \(g_{K^+{\mit \Lambda } p} \) and \(g_{K^+{\mit \Sigma }^0 p}\).

abstract

We have investigated the production potential of the spin-1/2 excited muons, predicted by preonic models, at the four SPPC (Super Proton–Proton Collider)-based muon–proton colliders in different center-of-mass energies. For the signal process \(\mu p\rightarrow \mu ^{\star }X\rightarrow \mu \gamma X\), the production cross section and the decay width values of the excited muons have been calculated. The pseudorapidity and transverse momentum distributions of muons and photons in the final state have been obtained in order to choose the kinematical cuts best suited for enhancing the statistical signal of the excited muon signature. By applying these cuts, we report the discovery, observation and exclusion mass limits of the excited muons for two compositeness scale values, which are an energy level at which new interactions are expected to occur. It is shown that the discovery limits on the excited muons in the case the compositeness scale equals 100 TeV are 2.7, 3.9, 3.1 and 6.7 TeV for center-of-mass energies of 10.3, 14.2, 14.6 and 20.2 TeV, respectively.

abstract

In this study, the angular distribution of the \(^{16}\)O\(+^{10}\)B elastic scattering was measured at \(E_{\rm lab}(^{16}{\rm O})=24\) MeV. In addition to our experimental data, this nuclear system was theoretically analyzed at different energies to study the dynamics of scattering for this system. The data were analyzed within the framework of the double-folding optical potential model. The values of the spectroscopic amplitudes (SA) for the configuration \(^{16}{\rm O}\to ^{10}\)B\(+^6\)Li were extracted at the energies at which the effect of the \(^6\)Li cluster transfer on the cross sections at backward angles is observed. The energy dependence of the reaction cross section for this system was also investigated.

abstract

Time-of-Flight methods have been rapidly developed and recently used in many experiments for determination of particle direction, identification of particles and energy resolutions. This paper describes a method of time-mark determination on the reconstruction algorithm, based on the sampled signal, used for time-of-flight measurements. This method was developed for distinguishing the signals which were received from scintillator detector with a silicon photomultiplier readout developed for a cosmic ray counter telescope by fitting to pulse shape. The method was verified using experimental data taken in the location \(40^\circ 54'52''\)N and \(38^\circ 19'26''\)E with the elevation of 30 m above the sea level. The data samples were acquired by the counters which have a scintillator with dimensions of \(20\times 20\times 1.4\) cm\(^3\), optically coupled from one side to silicon photomultiplier, then the signals read out by fast sampling digitizer board Domino Ring Sampler board version 4. The method can reconstruct each pulse even for multiple events without losing the count within the small time window. Using this method, 4.969 ns time-of-flight value was established and the rise times for scintillation counters, named Tile 1 and Tile 2, were measured to be about \(6.27 \pm 0.16\) ns and \(4.979\pm 0.165\) ns, respectively.

abstract

The experimental total production cross sections of intermediate mass fragments (isotopes of Li, Be, B, C, N, O, F, Ne, Na, and Mg) were extracted by integration of d\(^{2}\sigma \)/d\({\mit \Omega }\) d\(E\) data measured at several angles for \(p\)+Ag collisions at proton beam energy of 480 MeV. The total cross sections show typical odd–even staggering (OES) when presented as a function of the atomic number \(Z\) of ejectiles. The effect is the strongest for products with \(N=Z\) and \(N=Z+2\). Similar behaviour is observed for theoretical cross sections evaluated in the two-step model in which the first stage of the reaction is described by intranuclear cascade INCL\(++\) and the second stage by GEMINI\(++\) model or by two other models, namely ABLA07 and SMM. The OES seems to be even more pronounced for theoretical than for the experimental cross sections.

abstract

A precise description of the morphology of a material is necessary in order to establish structural and functional relationships. Tools for morphological analysis should be quantitative techniques, which would yield objective and reproducible values for any morphological structure and enable statistically defined comparisons. The combination of the stereological analysis and fractal analysis provides the researchers with such a tool. This work investigated hybrid alginate membranes filled with various amount of magnetite (Fe\(_3\)O\(_4\)) and crosslinked using four different agents, i.e. calcium chloride (AlgCa), phosphoric acid (AlgP), glutaraldehyde (AlgGA) and citric acid (AlgC). Alginate membranes can be used to dehydrate ethanol in the process of pervaporation. The morphology of studied membranes was characterized on the basis of the image analysis of the membrane cross sections obtained from a scanning electron microscope Phenom Pro-X. The quantitative analysis of the structure and morphology of the above-named materials was conducted by using a new tool: stereological–fractal analysis (the so-called SFA method). The SFA method was based on the shape descriptors (elongation factor, surface factor, irregularity parameter and bulkiness), fractal dimension, generalized fractal dimension and lacunarity. In relation to the membranes subjected to the tests, it was possible to identify the correlation between transport properties (pervaporation separation index (PSI)) and morphological parameters. The use of a comprehensive analysis made it possible to determine the morphology of the membrane with the best separation properties.