Modular detector for deep underwater registration of muons and muon groups

Registration and identification of muons and muon groups penetrating into the ocean depth, can be performed using a modular multilayer detector with high resolution bidimensional readout - deep underwater calorimeter (project NADIR). Laboratory testing of a prototype sensor cell with liquid scintillator in light-tight casing, testifies to the practicability of the full-scale experiment within reasonable expences

A search for J^{PC}=1^{-+} exotic mesons in the pi- pi- pi+ and pi- pi0 pi0 systems

A partial wave analysis (PWA) of the pi-pi-pi+ and pi-pi0pi0 systems produced in the reaction pi- p -> (3pi)-p at 18 GeV/c was carried out using an isobar model assumption. This analysis is based on 3.0M pi-pi0pi0 events and 2.6M pi-pi-pi+ events and shows production of the a2(1320), pi2(1670) and \pi(1800) mesons. An earlier analysis of 250K pi-pi-pi+ events from the same experiment showed possible evidence for a J^{PC}=1^{-+}$ exotic meson with a mass of 1.6 GeV/c^2 decaying into rho pi. In this analysis of a higher statistics sample of the (3pi)- system in two charged modes we find no evidence of an exotic meson.Comment: 4 pages, 5 figures, added comment about the negative reflectivity exotic wave

ВЗАИМОСВЯЗИ ВНЕШНЕГО ВОЗДЕЙСТВИЯ С АДАПТИВНОЙ СИСТЕМОЙ ШКВОРНЕВОГО УЗЛА

In a system of a railcar the node «center plate – center pad» is one of the most responsible in the bogies. One of the promising ways to solve the problem of increasing longevity, reducing a wear rate of thrust and bearing surfaces of a center plate and a center pad is to implement the principles of adaptive control in mechanical systems. Theoretical studies were carried out to find an optimal mode of node’s functioning, in which the processes of friction will occur in the lubricating layer that provides a minimum value of a coefficient of friction and wear rate. Their results are presented in this article.В системе железнодорожного вагона узел «пятник-подпятник» относится к наиболее ответственным в конструкциях ходовых тележек. Одним из перспективных способов решения проблемы повышения долговечности, снижения интенсивности износа упорной и опорной поверхностей пятника и подпятника является реализация принципов адаптивного управления в механических системах. Для поиска оптимального режима работы узла, при котором процессы трения будут происходить в смазочном слое, что обеспечит минимальное значение коэффициента трения и интенсивности износа, были проведены теоретические исследования. Их результаты представлены в публикуемой статье

FORECASTING RESIDUAL LIFE OF POWERGENERATING EQUIPMENT OF NPP

The problem of forecasting the residual life of power–generating equipment of NPP is solved in the framework of the mathematical model of the continuous Markov process of accumulating the number of defects in NPP equipment, this model is verified as well. The forecast function of the number of defects was obtained on the basis of the Fokker-Planck equations solutions and the theoretical residual resource of power–generating equipment was calculated.В рамках математической модели непрерывного марковского процесса накопления числа дефектов оборудования АЭС решается задача прогнозирования остаточного ресурса энергетического оборудования АЭС, а также проводится верификация математической модели. В работе получена функция прогноза числа дефектов на основе решения уравнения Фоккера-Планка, и рассчитан теоретический остаточный ресурс энергетического оборудования

Mathematical modeling of excitation and suppression of xenon oscillations

Within the framework of the non-linear mathematical model of a two-point reactor based on generalized experiments on actions and suppression of axial xenon oscillations.В рамках нелинейной математической модели двухточечного реактора на основе численных экспериментов решается задача возбуждения и подавления аксиальных ксеноновых колебаний

Confirmation of a pi_1^0 Exotic Meson in the \eta \pi^0 System

The exclusive reaction $\pi^- p \to \eta \pi^0 n$, $\eta \to \pi^+ \pi^- \pi^0$ at 18 GeV$/c$ has been studied with a partial wave analysis on a sample of 23~492 $\eta \pi^0 n$ events from BNL experiment E852. A mass-dependent fit is consistent with a resonant hypothesis for the $P_+$ wave, thus providing evidence for a neutral exotic meson with $J^{PC} = 1^{-+}$, a mass of $1257 \pm 20 \pm 25$ MeV$/c^2$, and a width of $354 \pm 64 \pm 60$ MeV$/c^2$. New interpretations of the meson exotics in neutral $\eta \pi^0$ system observed in E852 and Crystal Barrel experiments are discussed.Comment: p3, rewording the paragraph (at the bottom) about the phase variations. p4, rewording paragrath "The second method ..." . p4, at the bottom of paragrath "The third method ..." added consistent with the results of methods 1 and 2

Exotic Meson Production in the f1(1285)π−f_{1}(1285)\pi^{-} System observed in the Reaction π−p→ηπ+π−π−p\pi^{-} p \to \eta\pi^{+}\pi^{-}\pi^{-} p at 18 GeV/c

This letter reports results from the partial wave analysis of the $\pi^{-}\pi^{-}\pi^{+}\eta$ final state in $\pi^{-}p$ collisions at 18GeV/c. Strong evidence is observed for production of two mesons with exotic quantum numbers of spin, parity and charge conjugation, $J^{PC} = 1^{-+}$ in the decay channel $f_{1}(1285)\pi^{-}$. The mass $M = 1709 \pm 24 \pm 41$ MeV/c^2 and width $\Gamma = 403 \pm 80 \pm 115$ MeV/c^2 of the first state are consistent with the parameters of the previously observed $\pi_{1}(1600)$. The second resonance with mass $M = 2001 \pm 30 \pm 92$ MeV/c^2 and width $\Gamma = 333 \pm 52 \pm 49$ MeV/c^2 agrees very well with predictions from theoretical models. In addition, the presence of $\pi_{2}(1900)$ is confirmed with mass $M = 2003 \pm 88 \pm 148$ MeV/c^2 and width $\Gamma = 306 \pm 132 \pm 121$ MeV/c^2 and a new state, $a_{1}(2096)$, is observed with mass $M = 2096 \pm 17 \pm 121$ MeV/c^2 and width $\Gamma = 451 \pm 41 \pm 81$ MeV/c^2. The decay properties of these last two states are consistent with flux tube model predictions for hybrid mesons with non-exotic quantum numbers

Observation of Pseudoscalar and Axial Vector Resonances in pi- p -> K+ K- pi0 n at 18 GeV

A new measurement of the reaction pi- p -> K+ K- pi0 n has been made at a beam energy of 18 GeV. A partial wave analysis of the K+ K- pi0 system shows evidence for three pseudoscalar resonances, eta(1295), eta(1416), and eta(1485), as well as two axial vectors, f1(1285), and f1(1420). Their observed masses, widths and decay properties are reported. No signal was observed for C(1480), an IG J{PC} = 1+ 1{--} state previously reported in phi pi0 decay.Comment: 7 pages, 6 figs, to be submitted to Phys. Let

Observation of a New J(PC)=1(+-) Isoscalar State in the Reaction Pi- Proton -> Omega Eta Neutron at 18 GeV/c

Results are presented on a partial wave analysis of the Omega Eta final state produced in Pi- Proton interactions at 18 GeVc where Omega -> Pi+ Pi- Pi0, Pi0 -> 2 Gammas, and Eta -> 2 Gammas. We observe the previously unreported decay mode Omega(1650) -> Omega Eta and a new 1(+-) meson state h1(1595) with a mass M=1594(15)(+10)(-60) MeV/c^2 and a width Gamma=384(60)(+70)(-100) MeV/c^2. The h1(1595) state exhibits resonant-like phase motion relative to the Omega(1650).Comment: Submitted to Physics Letters B Eight total pages including 11 figures and 1 tabl