Production cross section of At radionuclides from 7^{7}Li+nat^{\textrm{nat}}Pb and 9^{9}Be+nat^{\textrm{nat}}Tl reactions

Earlier we reported theoretical studies on the probable production of astatine radionuclides from $^{6,7}$Li and $^{9}$Be-induced reactions on natural lead and thalliun targets, respectively. For the first time, in this report, production of astatine radionuclides has been investigated experimentally with two heavy ion induced reactions: $^{9}$Be+$^{\textrm{nat}}$Tl and $^{7}$Li+$^{\textrm{nat}}$Pb. Formation cross sections of the evaporation residues, $^{207,208,209,210}$At, produced in (HI, xn) channel, have been measured by the stacked-foil technique followed by the off-line $\gamma$-spectrometry at the low incident energies ($<$50 MeV). Measured excitation functions have been explained in terms of compound nuclear reaction mechanism using Weisskopf-Ewing and Hauser-Feshbach model. Absolute cross section values are lower than the respective theoretical predictions.Comment: 11 pages 6 figure

ИНДИВИДУАЛЬНОЕ ПРОГНОЗИРОВАНИЕ КАЧЕСТВА И ТЕХНИЧЕСКОГО СОСТОЯНИЯ СРЕДСТВ МЕДИЦИНСКОЙ ЭЛЕКТРОНИКИ МЕТОДОМ ПОРОГОВОЙ ЛОГИКИ

Results of working out of the program for individual forecasting of quality and technical condition of means of medical electronics by a method of threshold logic and algorithm of work with the program are resulted by working out of a solving rule for forecasting. The operator of forecasting allows to develop a software package operatively and qualitatively. It can be used both in the educational purposes, and for real individual forecasting of a technical condition concrete of means of medical electronics.Приведены результаты разработки программы для индивидуального прогнозирования качества и технического состояния средств медицинской электроники (СМЭ) методом пороговой логики и алгоритм работы с программой при разработке решающего правила для прогнозирования. Программный пакет позволяет оперативно и качественно разработать оператор прогнозирования. Он может использоваться как в учебных целях, так и для реального индивидуального прогнозирования технического состояния конкретного СМЭ

An attempt to explore the production routes of Astatine radionuclides: Theoretical approach

In order to fulfil the recent thrust of Astatine radionuclides in the field of nuclear medicine various production routes have been explored in the present work. The possible production routes of $^{209-211}$At comprise both light and heavy ion induced reactions at the bombarding energy range starting from threshold to maximum 100 MeV energy. For this purpose, we have used the nuclear reaction model codes TALYS, ALICE91 and PACE-II. Excitation functions of those radionuclides, produced through various production routes, have been calculated using nuclear reaction model codes and compared with the available measured data. Contribution of various reaction mechanisms, like, direct, preequilibrium and equilibrium reactions, to the total reaction cross section has been studied using the codes. Result shows that equilibrium reaction mechanism dominates in all cases over other reaction mechanisms

Cosmological constraints on R-parity violation from neutrino decay

If the neutrino mass is non-zero, as hinted by several experiments, then R-parity-violating supersymmetric Yukawa couplings can drive a heavy neutrino decay into lighter states. The heavy neutrino may either decay radiatively into a lighter neutrino, or it may decay into three light neutrinos through a Z-mediated penguin. For a given mass of the decaying neutrino, we calculate its lifetime for the various modes, each mode requiring certain pairs of R-parity-violating couplings be non-zero. We then check whether the calculated lifetimes fall in zones allowed or excluded by cosmological requirements. For the latter case, we derive stringent new constraints on the corresponding products of R-parity-violating couplings for given values of the decaying neutrino mass.Comment: 13 pages, Latex, uses axodraw.sty; version to appear in Physical Review

Conference of Soviet and American Jurists on the Law of the Sea and the Protection of the Marine Environment

Included in the papers for the Conference of Soviet and American Jurists on the Law of the Sea and the Protection of the Marine Environment: Introduction by Milton Katz and Richard R. Baxter, p. 1 Freedom of Scientific Research in the World Ocean by A.F. Vysotsky, p. 7 The International Law of Scientific Research in the Oceans by Richard R. Baxter, p. 27 Responsibility and Liability for Harm to the Marine Environment by Robert E. Stein, p. 41 Liability for Marine Environment Pollution Damage in Contemporary International Sea Law by A. L. Makovsky, p. 59 Protection of the Marine Environment from Pollution by Richard A. Frank, p. 73 The Freedom of Navigation and the Problem of Pollution of the Marine Environment by V. A. Kiselev, p. 93 The Freedom of Navigation Under International Law by William E. Butler, p. 107 International Fisheries Management Without Global Agreement: United States Policies and Their Impact on the Soviet Union by H. Gary Knight, p. 119 Some Biological Background for International Legal Acts on Rational Utilization of the Living Resources of the World Ocean by P. A. Moiseev, p. 143 An International Regime for the Seabed Beyond National Jurisdiction by Thomas M. Franck, p. 151 Settlement of Disputes Under the Law of Ocean Use, with Particular Reference to Environmental Protection by John Lawrence Hargrove, p. 18

Decoupling property of the supersymmetric Higgs sector with four doublets

In supersymmetric standard models with multi Higgs doublet fields, selfcoupling constants in the Higgs potential come only from the D-terms at the tree level. We investigate the decoupling property of additional two heavier Higgs doublet fields in the supersymmetric standard model with four Higgs doublets. In particular, we study how they can modify the predictions on the quantities well predicted in the minimal supersymmetric standard model (MSSM), when the extra doublet fields are rather heavy to be measured at collider experiments. The B-term mixing between these extra heavy Higgs bosons and the relatively light MSSM-like Higgs bosons can significantly change the predictions in the MSSM such as on the masses of MSSM-like Higgs bosons as well as the mixing angle for the two light CP-even scalar states. We first give formulae for deviations in the observables of the MSSM in the decoupling region for the extra two doublet fields. We then examine possible deviations in the Higgs sector numerically, and discuss their phenomenological implications.Comment: 26 pages, 24 figures, text sligtly modified,version to appear in Journal of High Energy Physic

Mass Bounds on a Very Light Neutralino

Within the Minimal Supersymmetric Standard Model (MSSM) we systematically investigate the bounds on the mass of the lightest neutralino. We allow for non-universal gaugino masses and thus even consider massless neutralinos, while assuming in general that R-parity is conserved. Our main focus are laboratory constraints. We consider collider data, precision observables, and also rare meson decays to very light neutralinos. We then discuss the astrophysical and cosmological implications. We find that a massless neutralino is allowed by all existing experimental data and astrophysical and cosmological observations.Comment: 36 pages, 13 figures, minor modification in astro-physical bounds. EPJC versio

The Hunt for New Physics in the Flavour Sector with up vector-like quarks

We analyse the possible presence of New Physics (NP) in the Flavour Sector and evaluate its potential for solving the tension between the experimental values of \AJPKs and \BTNu with respect to the Standard Model (SM) expectations. Updated model independent analyses, where NP contributions are allowed in Bd - anti-Bd and Bs - anti-Bs transitions, suggest the need of New Physics in the $bd$ sector. A detailed analysis of recent Flavour data is then presented in the framework of a simple extension of the SM, where a $Q=2/3$ vector-like isosinglet quark is added to the spectrum of the SM. Special emphasis is given to the implications of this model for correlations among various measurable quantities. We include constraints from all the relevant quark flavour sectors and give precise predictions for selected rare processes. We find important deviations from the SM in observables in the $bd$ sector like the semileptonic asymmetry \asld, $B_{d}^{0}\to \mu ^{+}\mu ^{-}$ and $A^s_{SL}-A^d_{SL}$. Other potential places where NP can show up include $A_{J/\Psi\Phi}$, $\gamma$, $K_{L}^{0}\to \pi^{0}\nu \bar{\nu}$, $t\to Zq$ and $D^{0}\to \mu ^{+}\mu ^{-}$ among others. The experimental data favours in this model the existence of an up vector-like quark with a mass below $600(1000)$ GeV at $1(2)$ $\sigma$.Comment: 36 pages, 41 figures; minor changes and references added, matches version accepted for publicatio