Physics of Atomic Nuclei最新文献

The DEAP-3600 experiment uses a modern coordinate reconstruction algorithm that utilizes machine learning. This algorithm performed well compared to likelihood-based approaches. Here we validate our neural network based algorithm on data obtained using ({}^{241})Am–({}^{9})Be radioactive source. The results obtained confirm algorithm validity.

Double Side Silicon Detector (DSSD) based spectrometer of the DGFRS-2 setup has been applied in different heavy ion induced complete fusion nuclear reactions leading to formation of superheavy nuclei. Nuclear reactions with ({}^{48})Ca, ({}^{54})Cr, ({}^{50})Ti, ({}^{40})Ar projectiles were used. Targets of ({}^{238})U, ({}^{242})Pu, ({}^{243})Am,({}^{232})Th, ({}^{nat})Yb were used in the long term irradiations. We report about different stability tests during this long term experiment. Formation of the evaporation residue (ER) registered energy spectrum measured with DSSD focal plane detector is presented.

In the Chiral-Invariant Phase Space Model constituent quarks of hadrons are embedded in nonperturbative vacuum with a boiling temperature (T_{c}). The color-electric binding energy is proportional to the reduced energy of quarks. The mean spin products for the color-magnetic shifts are calculated according to the simplified para-statistics rules. The 61 hadron masses are fitted by 8 parameters, including (T_{c}) and 5 quark masses. Masses of the 21 hadrons including double and triple heavy baryons are predicted.

The Sarov Tritium Neutrino Experiment (SATURNE) is designed to study coherent elastic neutrino–atom scattering (CE(nu)AS) and to search for the neutrino magnetic moment. The measurements will be performed in a low-background laboratory in Sarov using a liquid He-4 detector in a superfluid state and a high-intensity tritium source of electron antineutrinos. The He-4 detector with a total volume of 1000 liters will operate at a temperature between 40 and 60 mK and will be sensitive to energy signals of the order of a few meV due to the quantum evaporation channel. The tritium source will have an activity of about at least 10 MCi and possibly up to 40 MCi. It is expected that after five years of data collection, SATURNE will be able to report the first observation of the CE(nu)AS process. By measuring this neutrino interaction channel, it will achieve sensitivity to the neutrino magnetic moment (mu_{nu}) at a level of ({sim}10^{-13},mu_{textrm{B}}), which is about an order of magnitude better than the current world-leading constraints.

The TAIGA observatory addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from 100 TeV to several EeV and astroparticle physics. The TAIGA experiment current status, recent results and development prospects are presented.

The opaque scintillator detector is a novel concept of a new generation of position-sensitive detectors. The main idea is to localize the light near the point of its scintillation using an optically scattering medium. The first published results by the LiquidO Collaboration are based on the application of an opaque liquid scintillator. Our approach suggests the usage of media based on a solid granular organic scintillator and an array of WLS fibers with SiPMs as photodetectors. The report describes new results obtained during the beam test of different configurations of scintillating and scattering media with external proportional chambers as a tracking system. The results of the media comparison and the estimation of the track reconstruction accuracy are presented.

Pion production in AA collisions in a new cumulative region of central rapidities and large transverse momenta accessible for experimental study at the SPD and MPD facilities of the NICA collider is considered. The asymptotic behavior of the inclusive cross section at high initial energies near the kinematic boundary is calculated and quark counting rules for this process are formulated. The obtained expressions give an explicit dependence of the inclusive cross section of cumulative pion production on the initial energy and cumulative number near the kinematic boundary of the AA collision.

The Super Fine-Grained neutrino Detector (SuperFGD) is a novel fully active neutrino detector and a key element of the upgraded near off-axis detector ND280 of the T2K experiment. SuperFGD is made of approximately 2000000 optically-isolated plastic scintillator 1 cm({}^{3}) cubes each one read out by three orthogonal wavelength shifting (WLS) fibers coupled to about 56000 silicon photomultipliers. The detector provides 4(pi) particle tracking with a proton detection threshold of about 300 MeV/c. A nanosecond single-channel time resolution allows to detect neutrons produced by neutrino interactions by time-of-flight. This paper presents the results of the calibration of SuperFGD readout channels using LED system and cosmic muons, as well as the detection of muon neutrinos through charged current interactions in the T2K neutrino beam. Special attention is paid to the reconstruction of muons and stopped protons in SuperFGD.

The (nd) breakup reaction at an energy of 5 MeV was studied on the RADEX neutron channel of the Institute for Nuclear Research of the Russian Academy of Sciences. As a result of comparing the experimental data with the simulation results, the energy of the virtual ({}^{1}S_{0}) (np) state (E_{np}=40pm 2) keV and the corresponding singlet (np) scattering length (a_{np}={-}30.9pm 0.8) fm were extracted. It was assumed that the obtained (a_{np}) value, together with the data of other experiments on the study of (nd) and (dd) breakup reactions at different energies, are subject to the influence of (3N) forces. The work was carried out as part of a series of studies on internucleon interactions at low energies.

The interaction of fast neutrons with the ({}^{10})B nucleus at energies from 3 to 7 MeV is studied with the aim of isolating the reaction with the production of the ({}^{8}textrm{Be}^{*}) nucleus in an excited state. This reaction stands out from the three-body reaction with the emission of triton and two (alpha) particles. Simulation of ionization losses of secondary ({}^{3})H and ({}^{4})He nuclei in solid and gas layers of position-sensitive multiwire detectors with sensitive sizes of both (100times 100) and (50times 50) mm({}^{2}) showed that events are localized in different areas in diagrams plotted from losses in two gas layers. Experimental result, with (100times 100) mm({}^{2}) detector showed the possibility of isolating a reaction with the emission of ({}^{3})H and ({}^{8}textrm{Be}^{*}) nuclei.