Physics of Particles and Nuclei Letters最新文献

In this work, the theoretical analysis of the yields of heavy neutron-enriched isotopes with the magic number (N = 126) obtained in the multinucleon transfer reactions (^{{132}})Sn, (^{{136, 138, 140}})Xe + (^{{198}})Pt is presented. Calculations have been carried out within the multidimensional dynamic model based on Langevin equations, which describes well enough the available experimental data on the (^{{136}})Xe + (^{{198}})Pt reaction with the stable projectile (^{{136}})Xe. The use of neutron-enriched radioactive projectiles (^{{132}})Sn, (^{{138, 140}})Xe in multinucleon transfer reactions with the (^{{198}})Pt target leads to an increase in the production cross section of neutron-enriched heavy nuclides.

Abstract

The species similarity of corneal collagen in animal grafts was studied using small-angle X-ray scattering and Raman spectroscopy. Detailed analysis of the Raman spectra in the range of 1500–1700 cm^–1 for human, porcine, and horse grafts demonstrated that bands associated with proteins and amino acids do not exhibit obvious differences in the structure of corneal grafts. Parameters of the internal structure of collagen obtained from scattering spectra also indicate the species similarity of corneal collagen in grafts. Satisfactory results of layer-by-layer intralamellar implantation of porcine and horse grafts “Corneoplast” are presented.

In this paper we study the signal-to-background ratios for the (J{text{/}}psi )-meson associated and direct photon main production processes at the energies of SPD NICA experiment using the Monte Carlo generator PYTHIA8. We extract the set of kinematic constraints allowing to improve signal-to-background ratios. We compare the results of our simulation for the direct photon spectra in different intervals of ({{p}_{T}}) and ({{x}_{F}}) with the experimental data and present the predictions for signal-to-background ratios in direct photon production at the NICA energy of (sqrt s = 27) GeV.

The main objective of the Baikal-GVD neutrino telescope is to detect high-energy neutrinos from astrophysical sources, thus contributing to the advancement of modern understanding of the high-energy universe. In the present work, we estimate the total neutrino detection rate from several hypothetical and tentatively established neutrino sources including TXS 0506+056, NGC 1068, and the Galactic Center assuming the hadronic emission scenario. The neutrino rate is calculated using a pre-computed detector effective area for track-like events. The daily source movement across the sky and the detector’s registration efficiency as a function of the energy and zenith angle are taken into account. The attenuation of the neutrino flux in the Earth is modeled using the (nu FATE) package and is also incorporated into the neutrino detection rate calculations. We conclude that a 20-cluster version of Baikal-GVD is able to detect up to 10 neutrinos in 5 years on average at the trigger level for some sources. Taking into account the event reconstruction efficiency, the number of expected events with the current reconstruction mechanism is of the order of one event in every couple of years for the brightest sources.

Correlation femtoscopy allows one to estimate the spatial and temporal characteristics of the particle-emitting region formed in the relativistic heavy-ion collisions. Azimuthally-differential analysis is used to study shape and orientation of the source. In this work, collisions of isobaric nuclei Ru + Ru and Zr + Zr at (sqrt {{{s}_{{NN}}}} = 200) GeV are calculated using the UrQMD (Ultrarelativistic Quantum Molecular Dynamics) model and the azimuthally-differential two-pion femtoscopy relative to the second- and third-order event plane are performed. The extracted characteristics of the emission source are presented as a function of the pair transverse momentum, ({{k}_{T}}), collision centrality and the pair emission angle. In the future, the obtained results can be compared with the STAR experimental data.

Lindblad master equation (LME) for the density operator is applied to examine electron transport through a molecular junction with a ring component having two pathways for an electron propagation. Here the concept of quantum interference is addressed to check whether this phenomenon may influence the electric current in a far-from-equilibrium regime. The existence of two modes of electric current flow with and without the occurrence of a circular current in the benzene ring is shown, depending on the value of coupling (hopping parameter (J)) between the molecule and electrodes. LME is solved with the use of the open-source program code LindbladMPO that simulate elements of quantum algorithm on a classical computer.

Simulation of neutrino telescopes like IceCube, Baikal-GVD, KM3NET/ARCA is a long multi-stage process. NTSim is a framework efficiently chaining different stages of the simulation. Full Monte Carlo modeling of electromagnetic and hadron cascades usually consumes a lot of computational resources. In this contribution we present an efficient cascade parametrization of NTSim which allows to significantly reduce computation time and validate it against the full cascade modeling.

A new methodology for calculation of technical characteristics of electrostatic transducers has been developed, particularly, for capacitive micromachined ultrasound transducers (CMUT). It is based on a representation of the transducer as a flat capacitor with isotropic monolayer movable plate. Its displacement profile is calculated throughout superposition of its eigenmode responses to an applied voltage. The calculated displacement is used for determination of acoustic pressure in far-filed of an array of the similar transducers, vibrating in phase. Such a methodology makes it possible to calculate the frequency response and the radiation pattern even for a huge array of cells. It shows good accuracy in comparison to the finite element method (FEM), but is faster by an order of two.

The MPD Time-Projection Chamber (TPC) is the main tracking detector of the MPD experiment. Tracks coordinates are obtained by measurement of drift time of electrons from track position to readout chamber. The drift velocity of electrons can vary due to pressure, temperature, space charge effects, so it must be measured online. To solve this problem the laser calibration system is foreseen for this. The article presents an algorithm that provide drift velocity measurements and based on processing signal-in-time distributions.

The custom Application Specific Integrated Circuits (ASIC) Turin Integrated Gem Electronics for Readout (TIGER) has been developed at INFN-Torino and is capable of simultaneous precise measurements of both the charge and time characteristics of signals in micropattern gaseous detectors. Its flexibility makes it attractive as a front-end electronics solution for a wide range of applications, including readout systems of Straw Trackers in future High Energy and Neutrino Physics experiments. We present first performance measurements done with straw drift tubes operated with TIGER readout. Preliminary results obtained with the SPS muon beam at CERN are compared to the prediction of simulation studies done with GARFIEDL++ and LTSpice packages.