Physics of Particles and Nuclei Letters最新文献

Trimaximal mixing pattern (TM₁) of the neutrino mixing matrix is consistent with current neutrino oscillation data. In this work, we have investigated the phenomenology of inverse neutrino mass matrix ((m_{nu }^{{ - 1}})) with one-zero textures considering neutrino mixing matrix to be of TM₁ type. There are six possible patterns of (m_{nu }^{{ - 1}}) with one-zero. We have obtained the predictions for the least known neutrino sector parameters such as octant of atmospheric mixing angle, ({{theta }_{{23}}}), Dirac-type CP violating phase, δ, and effective Majorana neutrino mass, ({{m}_{{ee}}}). One of the generic feature of this class of model is the existence of necessary CP violation, i.e., Dirac CP phase δ is non-zero. For maximal value of ({{theta }_{{23}}} = 45^circ ), the model predicts maximal CP violation. The (0nu beta beta ) decay experiments have imperative consequences for viability of one-zero texture in (m_{nu }^{{ - 1}}). It will either refute a model completely or have distinguishing implications for neutrino mass ordering in a model. We have also proposed two possible scenarios in which such phenomenological conjecture may be realized using non-Abelian discrete flavor symmetry group ({{A}_{4}}) and cyclic group ({{Z}_{3}}).

Physical processes occurring during the propagation of a beam of accelerated electrons in the air are analyzed. The dynamics of particles in the air in the presence of an accompanying electromagnetic field is examined. The possibility of transporting electrons over long distances without a significant loss of beam intensity in the accompanying electromagnetic field was tested.

A prototype of the 325-MHz niobium half-wave coaxial resonator ((beta = 0.21)) is developed, built, and tested at low microwave field amplitudes. Electromagnetic properties of the prototype in the superconducting state are investigated in the continuous wave regime and the damping regime using a highly stable radio-frequency (RF) generator and power detectors. The experimental data on the resonator’s response in the superconducting state are used to calculate its most important characteristics—the intrinsic Q value and the accelerating field. The experimentally measured Q value of the prototype is ({{Q}_{0}} = (3.5 pm 0.1) times {{10}^{8}}) at input powers of up to +20 dBm.

The paper is devoted to the analysis of π^– meson production in (p + p), (n + p), (p + C), and ({{pi }^{ - }} + C) reactions at different projectile energies. The description of these processes is important in understanding of the structure of nuclear matter. A method based on a relativistically invariant variable introduced by us is applied. This method allows one to observe a regularity in π^– meson production for a wide set of reactions at different energies in terms of the relativistically invariant target mass variable. This gives grounds to assume that this representation has a predictive power and can be used in analysis of existing experimental data and planning experiments at the NICA accelerator complex.

This paper presents a design of a calibration system for the Light Readout System of the prototype modular Liquid Argon Time-Projection Chamber (LArTPC) of the Near Detector of the Deep Underground Neutrino Experiment (DUNE). The calibration system and its components have been tested at the Joint Institute for Nuclear Research (JINR) and during the prototype LArTPC trials conducted at the University of Bern, Switzerland. The results demonstrate that the system fulfills its intended functionality, allowing for the calibration of the photodetectors in the light-readout system of the LArTPC and the study of its temporal characteristics.

The creation of accelerators for the inspection of large objects during their transportation across state borders is an important task. To obtain high-quality images of the inspected object internal composition, the accelerator must be able to do a dual switch of beam energy from pulse to pulse [1]. A number of works are devoted to solving this problem, describing methods and real facilities with dual energy switch [2–5]. The energy switch is achieved by a stepwise change in the input power of the accelerating section and/or the magnitude of the accelerated current. In order to provide the necessary energy and beam current in high and low energy modes, the accelerating section parameters must be carefully tuned. This article compares two power supply schemes of a two-section linac with energy switch due to disconnection of one of the sections using circulators and bridges.

A mechanism is proposed in quantum fission theory that describes the appearance of large values of the spins of light (({{vec {J}}_{1}})) and heavy (({{vec {J}}_{2}})) fission fragments (FFs) and large relative orbital momentum (vec {L}). An important difference between the approach proposed in this study and the widely used statistical model, which assumes heating of the FFs to temperatures of the order of 1 MeV, is the “coldness” of the fissile nucleus at all stages of its evolution, starting from the descent of the nucleus from the outer saddle point and ending with the moment of its fission into the indicated fragments. The approach proposed, which makes it possible to describe the spin distributions (SD) of binary fission fragments, both in the case of induced fission of the ({}^{{232}}{text{Th}}left( {n,f} right)) and ({}^{{238}}{text{U}}left( {n,f} right)) nuclei and spontaneous fission of the ({}^{{252}}{text{Cf}}left( {s,f} right)) nucleus is based on the joint consideration of zero-point wriggling and bending oscillations.

The Eigen (quasispecies) model describes virus evolution via a system of nonlinear differential equations (nonlinear master equation). The model describes virus evolution, the origin of life, and some other phenomena of interdisciplinary research. Recently, M. Smerlak suggested a method by which these nonlinear models can be connected to Markov (linear) models. Here, we formulate Smerlak’s version of the Eigen model and solve the dynamics exactly at the large genome limit.

The velocity-dependent optical potential used in this work leads to a local energy-dependent potential that consists of real surface terms that are proportional to the derivatives of the nuclear matter density. Such term—in other works—has been accounted for nonlocality due to the surface deformation in the light nuclei. In the present work, we have examined the ability of the velocity-dependent potential, which contains real surface-peaked terms, to account for nonlocality. This is achieved by inspecting the case of fitting the angular distribution data for the neutron that elastically scattered from a light nucleus, carbon isotopes (¹⁰C, ¹²C, and ¹⁴C) in the energy range of 12–20 MeV, by using two potential models: the modified velocity optical potential (which conations real surface-term) and the conventional optical potential. A comparison between the two models has been made. Furthermore, the total elastic cross sections and the analyzing power are calculated using both models and compared to the experimental data. The volume integrals per nucleon of the real central potential and the imaginary surface potential in the modified velocity optical potential have also been determined and the results are in good agreement with the corresponding values calculated using other models. It is shown that a significant improvement in angular distributions was observed when the velocity-dependent potential was applied, specifically in the large angle scattering region and in certain energy ranges.

One way to increase the sensitivity of the precision laser inclinometer (PLI) is to change over from the photovoltaic mode to the reverse-biased photodiode mode. This allows a broader linear range and an improved signal-to-noise ratio. Additionally, this approach enables the use of lower resolution ADCs (14–16 bit instead of 24 bit), which significantly reduces the cost of the device. A study of the Hamamatsu S12915-1010R/66R, Thorlabs FDS-100, and Hamamatsu S3204-08 photodiodes is conducted to determine their linear range of operation in the photovoltaic and photodiode modes. The noise level of the CPLI readout channels is measured using closed photodiodes, and two modes of operation of the photodiodes in the CPLI on the signal channels are investigated. The research results indicate the possibility of using this mode of operation of photodiodes in the CPLI.