67 research outputs found

    B ->PV Decays in the QCD Improved Factorization Approach

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    Motivated by recent CELO measurements and the progress of the theory of B decays, we investigate BPV(P=π,K.V=K,ρ,ω)B\to P V(P=\pi,K. V= K^{*},\rho,\omega) decay modes in the framework of QCD improved factorization. We find that all the measured branching ratios are well accommodated in the reasonable parameter space and predictions for the other decay modes are well below the experimental upper limits. We also have calculated CP asymmetries in these decay modes.Comment: 24 pages, LaTex-2e, typos correcte

    The Q2Q^2 dependence of the hard diffractive photoproduction of vector meson or photon and the range of pQCD validity

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    We consider two coupled problems. We study the dependence on photon virtuality Q2Q^2 for the semihard quasi--elastic photoproduction of neutral vector mesons on a quark, gluon or real photon (at sp2,  Q2;  p2μ2(0.3s\gg p_{\bot}^2,\;Q^2; \; p_{\bot}^2\gg \mu^2 \approx (0.3 GeV)2^2). To this end we calculate the corresponding amplitudes (in an analytical form) in the lowest nontrivial approximation of perturbative QCD. It is shown that the amplitude for the production of light meson varies very rapidly with the photon virtuality near Q2=0Q^2=0. We estimate the bound of the pQCD validity region for such processes. For the real incident photon the obtained bound for the ρ\rho meson production is very high. This bound decreases fast with the increase of Q2Q^2, and we expect that the virtual photoproduction at HERA gives opportunity to test the pQCD results. The signature of this region is discussed. For the hard Compton effect the pQCD should work good at not too high pp_{\bot}, and this effect seems measurable at HERA.Comment: ReVTeX, 36 pages, 5 Postscript figures, uses epsf.st

    Excitonic Funneling in Extended Dendrimers with Non-Linear and Random Potentials

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    The mean first passage time (MFPT) for photoexcitations diffusion in a funneling potential of artificial tree-like light-harvesting antennae (phenylacetylene dendrimers with generation-dependent segment lengths) is computed. Effects of the non-linearity of the realistic funneling potential and slow random solvent fluctuations considerably slow down the center-bound diffusion beyond a temperature-dependent optimal size. Diffusion on a disordered Cayley tree with a linear potential is investigated analytically. At low temperatures we predict a phase in which the MFPT is dominated by a few paths.Comment: 4 pages, 4 figures, To be published in Phys. Rev. Let

    Proceedings of the third French-Ukrainian workshop on the instrumentation developments for HEP

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    The reports collected in these proceedings have been presented in the third French-Ukrainian workshop on the instrumentation developments for high-energy physics held at LAL, Orsay on October 15-16. The workshop was conducted in the scope of the IDEATE International Associated Laboratory (LIA). Joint developments between French and Ukrainian laboratories and universities as well as new proposals have been discussed. The main topics of the papers presented in the Proceedings are developments for accelerator and beam monitoring, detector developments, joint developments for large-scale high-energy and astroparticle physics projects, medical applications.Comment: 3rd French-Ukrainian workshop on the instrumentation developments for High Energy Physics, October 15-16, 2015, LAL, Orsay, France, 94 page

    Search for double beta decay processes in 106Cd with the help of 106CdWO4 crystal scintillator

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    A search for the double beta processes in 106Cd was carried out at the Gran Sasso National Laboratories of the INFN (Italy) with the help of a 106CdWO4 crystal scintillator (215 g) enriched in 106Cd up to 66%. After 6590 h of data taking, new improved half-life limits on the double beta processes in 106Cd were established at the level of 10^{19}-10^{21} yr; in particular, T_{1/2}(2\nu \epsilon \beta^+) > 2.1 10^{20} yr, T_{1/2}(2\nu 2\beta^+) > 4.3 10^{20} yr, and T_{1/2}(0\nu 2\epsilon) > 1.0 10^{21} yr. The resonant neutrinoless double electron captures to the 2718 keV, 2741 keV and 2748 keV excited states of 106Pd are restricted to T_{1/2}(0\nu 2K) > 4.3 10^{20} yr, T_{1/2}(0\nu KL1) > 9.5 10^{20} yr and T_{1/2}(0\nu KL3) > 4.3 10^{20} yr, respectively (all limits at 90% C.L.). A possible resonant enhancement of the 0\nu 2\epsilon processes is estimated in the framework of the QRPA approach. The radioactive contamination of the 106CdWO4 crystal scintillator is reported.Comment: Minor changes of half-life limits after improving the data analysis; version accepted for publication on Phys. Rev.

    Purification of molybdenum oxide, growth and characterization of medium size zinc molybdate crystals for the LUMINEU program

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    The LUMINEU program aims at performing a pilot experiment on neutrinoless double beta decay of 100Mo using radiopure ZnMoO4 crystals operated as scintillating bolometers. Growth of high quality radiopure crystals is a complex task, since there are no commercially available molybdenum compounds with the required levels of purity and radioactive contamination. This paper discusses approaches to purify molybdenum and synthesize compound for high quality radiopure ZnMoO4 crystal growth. A combination of a double sublimation (with addition of zinc molybdate) with subsequent recrystallization in aqueous solutions (using zinc molybdate as a collector) was used. Zinc molybdate crystals up to 1.5 kg were grown by the low-thermal-gradient Czochralski technique, their optical, luminescent, diamagnetic, thermal and bolometric properties were tested.Comment: Contribution to Proc. of Int. Workshop on Radiopure Scintillators RPSCINT 2013, 17-20 September 2013, Kyiv, Ukraine; to be published in EPJ Web of Conferences; expected to be online in January 2014; 6 pages, 6 figures, and 3 table

    Качество жизни больных хронической обструктивной болезнью легких в России: результаты многоцентрового популяционного исследования «ИКАР-ХОБЛ»

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    The objective of the “IKAR-COPD” study was to evaluate quality of life in COPD patients with different treatment regimens. This multi-center population-based study was performed in 10 regions of Russia, 702 COPD patients aged 40 to 85 yrs were included in this study: 18.5 % with COPD stage I, 20.7 % with COPD stage II, 40.9 % with COPD stage III and 19.9 % with COPD stage IV (according to the GOLD 2003 criteria). The official Russian versions of the MOS SF-36 questionnaire and the St. George’s Respiratory Questionnaire (SGRQ) were used as generic and disease-specific health-related measures of quality of life. COPD significantly impaired the patients’ quality of life, mostly their physical activity. The quality of life depended on severity of COPD, a patient’s age, duration of the disease and smoking history.Целью исследования «ИКАР-ХОБЛ» было изучение влияния хронической обструктивной болезни легких (ХОБЛ) и тактики ее лечения на качество жизни (КЖ) больных. Многоцентровое популяционное исследование проведено в 10 регионах РФ. В него были включено 702 пациента с ХОБЛ в возрасте от 40 до 85 лет: 18,5 % пациентов — с I стадией, 20,7 % – со II стадией, 40,9 % – с III стадией и 19,9 % – с IV стадией ХОБЛ (по критериям GOLD, 2003). Исследование КЖ проводилось с использованием общего «Краткого вопросника оценки статуса здоровья» (официального русскоязычного аналога вопросника MOS SF-36), и русскоязычной версии «Респираторного вопросника госпиталя Святого Георгия» – St. George’s Respiratory Questionnaire (SGRQ). Выявлено, что ХОБЛ оказывает выраженное негативное воздействие на КЖ пациентов, в первую очередь на их физический статус. Выраженность отклонений определяется степенью тяжести ХОБЛ, возрастом пациентов, длительностью заболевания, индексом курения

    Ethanol reforming in non-equilibrium plasma of glow discharge

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    The results of a detailed kinetic study of the main plasma chemical processes in non-equilibrium ethanol/argon plasma are presented. It is shown that at the beginning of the discharge the molecular hydrogen is mainly generated in the reaction of ethanol H-abstraction. Later hydrogen is formed from active H, CH2OH and CH3CHOH and formaldehyde. Comparison with experimental data has shown that the used kinetic mechanism predicts well the concentrations of main species at the reactor outlet.Comment: 16 pages, 8 figure

    Development of 100^{100}Mo-containing scintillating bolometers for a high-sensitivity neutrinoless double-beta decay search

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    We report recent achievements in the development of scintillating bolometers to search for neutrinoless double-beta decay of 100^{100}Mo. The presented results have been obtained in the framework of the LUMINEU, LUCIFER and EDELWEISS collaborations, and are now part of the R\&D activities towards CUPID (CUORE Update with Particle IDentification), a proposed next-generation double-beta decay experiment based on the CUORE experience. We have developed a technology for the production of large mass (\sim1 kg), high optical quality, radiopure zinc and lithium molybdate crystal scintillators (ZnMoO4_4 and Li2_2MoO4_4, respectively) from deeply purified natural and 100^{100}Mo-enriched molybdenum. The procedure is applied for a routine production of enriched crystals. Furthermore, the technology of a single detector module consisting of a large-volume (100\sim 100~cm3^3) Zn100^{100}MoO4_4 and Li2_2100^{100}MoO4_4 scintillating bolometer has been established, demonstrating performance and radiopurity that are close to satisfy the demands of CUPID. In particular, the FWHM energy resolution of the detectors at 2615 keV --- near the QQ-value of the double-beta transition of 100^{100}Mo (3034~keV) --- is \approx 4--10~keV. The achieved rejection of α\alpha-induced dominant background above 2.6~MeV is at the level of more than 99.9\%. The bulk activity of 232^{232}Th (228^{228}Th) and 226^{226}Ra in the crystals is below 10 μ\muBq/kg. Both crystallization and detector technologies favor Li2_2MoO4_4, which was selected as a main element for the realization of a CUPID demonstrator (CUPID-0/Mo) with \sim7 kg of 100^{100}Mo
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