Leptonic and charged kaon decay modes of the phi meson measured in heavy-ion collisions at the CERN super proton synchrotron

We report on results of a measurement of meson production in central Pb-Au collisions at E(lab) = 158A GeV. For the first time in the history of high energy heavy-ion collisions, phi mesons were reconstructed both in the K+K- and the dilepton decay channels in the same experiment. This measurement yields rapidity densities near midrapidity, from the two decay channels, of 2.05 +/- 0.14(stat) +/- 0.25(syst) and 2.04 +/- 0.49(stat) +/- 0.32(syst), respectively. The shape of the measured transverse momentum spectrum is also in close agreement in both decay channels. The data rule out a possible enhancement of the phi yield in the leptonic over the hadronic decay channel of a factor 1.6 or larger at the 95% C.L. This rules out the discrepancy reported in the literature between measurements of the hadronic and dimuon decay channels by two different experiments.     

Design,synthesis and experimental validation of novel potential chemopreventive agents using random forest and support vector machine binary classifiers

Compared to the current knowledge on cancer chemotherapeutic agents, only limited information is available on the ability of organic compounds, such as drugs and/or natural products, to prevent or delay the onset of cancer. In order to evaluate chemical chemopreventive potentials and design novel chemopreventive agents with low to no toxicity, we developed predictive computational models for chemopreventive agents in this study. First, we curated a database containing over 400 organic compounds with known chemoprevention activities. Based on this database, various random forest and support vector machine binary classifiers were developed. All of the resulting models were validated by cross validation procedures. Then, the validated models were applied to virtually screen a chemical library containing around 23,000 natural products and derivatives. We selected a list of 148 novel chemopreventive compounds based on the consensus prediction of all validated models. We further analyzed the predicted active compounds by their ease of organic synthesis. Finally, 18 compounds were synthesized and experimentally validated for their chemopreventive activity. The experimental validation results paralleled the cross validation results, demonstrating the utility of the developed models. The predictive models developed in this study can be applied to virtually screen other chemical libraries to identify novel lead compounds for the chemoprevention of cancers.     

On the coexistence of corank 1 multisingularities of a stable smooth mapping of equidimensional manifolds

We study the topology of stable smooth mappings of smooth closed real manifolds of the same dimension. We calculate all universal linear relations between the Euler characteristics of the manifolds of multisingularities of mappings that have only corank 1 singularities. Published in Russian in Trudy Matematicheskogo Instituta imeni V. A. Steklova, 2007, vol. 258, pp. 201–226. Dedicated to Vladimir Igorevich Arnold on the occasion of his 70th birthday     

57Fe Mössbauer study of YBa4Cu2.95Fe0.05O8.5+y

⁵⁷Fe Mössbauer measurements were performed on the Fe-doped YBa₄Cu₃O_8.5+y compound as a function of annealing temperature in vacuum. Mössbauer spectra were analyzed using three different quadrupole split doublets. The resistance measurements showed that the compound is not superconducting. The possible identification of the Cu sites with their nearest neighbor oxygen sites in this compound is suggested. Comparison of the results with data of the presence of the superconductor YBa₂Cu₃O₇ allows us to suppose that the presence of the Cu-chain sites alone does not result in superconductivity.     

The topology of corank 1 multi-singularities of stable smooth mappings of equidimensional manifolds

We study conditions for the coexistence of singularities of a stable smooth mapping of a closed manifold into a manifold of the same dimension n. Assuming that this mapping has only singularities of corank 1, we find universal linear relations between the Euler characteristics of the manifolds of multi-singularities in the image of the considered mapping. To cite this article: V.D. Sedykh, C. R. Acad. Sci. Paris, Ser. I 340 (2005).     

Structural transitions in La 0.95 Ba 0.05 Mn 0.98 57 Fe 0.02 O 3 under heat treatment

Structural transitions in polycrystalline Ba-doped lanthanum manganite La_0.95Ba_0.05Mn_0.98Fe_0.02O_3?+?δ have been investigated under different cooling conditions after vacuum annealing (fast and slow cooling) by Mössbauer spectroscopy and X-ray diffraction (XRD) analysis. A rhombohedral structure of the synthesized La_0.95Ba_0.05Mn_0.98Fe_0.02O_3?+?δ sample transfers into a mixture of the orthorhombic PnmaI, PnmaII* and PnmaII phases (common space group Pnma) with a stoichiometric oxygen composition under vacuum annealing. The further vacuum annealing leads to fluctuations in a partial relation of the orthorhombic phases on fast cooling. This unusual behavior of the structural transitions are discussed.     

Thermometry System of NICA Booster Superconducting Magnets

Physics of Particles and Nuclei Letters - The NICA accelerator complex is developed on the JINR base in Dubna for performing physical experiments on colliding beams of heavy ions. It consists of...     

A complete system of linear relations between the Euler characteristics of manifolds of corank 1 singularities of a generic front

A compact stable front with corank 1 singularities is considered. The topological Euler characteristic of each odd-dimensional manifold of singularities of such a front is a universal linear combination of the Euler characteristics of even-dimensional singularity manifolds of higher codimensions. We prove that there are no other universal linear relations between the Euler characteristics of manifolds of singularities of such fronts.Translated from Funktsionalnyi Analiz i Ego Prilozheniya, Vol. 38, No. 4, pp. 73–78, 2004Original Russian Text Copyright © by V. D. SedykhSupported in part by RFBR grant 02-01-00655 and Support of Scientific Schools grant 1972. 2003. 1.     

Enhanced production of low-mass electron-positron pairs in 40-AGeV Pb-Au collisions at the CERN SPS

We report on first measurements of low-mass electron-positron pairs in Pb-Au collisions at the CERN SPS beam energy of 40 AGeV. The observed pair yield integrated over the range of invariant masses 0.2e(+)e(-) annihilation with a modified rho propagator. They may be linked to chiral symmetry restoration and support the notion that the in-medium modifications of the rho are more driven by baryon density than by temperature.