13 research outputs found

    The method for high order modes parameters estimation in periodical structures

    No full text
    The High Order Modes (HOM) parameters are calculated in traveling wave mode at one structure period for the reference set of the phase advance values, with real 3D geometry in the wide frequency range. For the structure with arbitrary length HOM parameters are interpolated basing on periodicity properties. The method resolution doesn’t depends on the number of periods in the structure and allows reliably identify interesting and important HOM parameters for long structures and in high frequency region.ВЧ-характеристики высших мод колебаний (ВМК) рассчитаны в режиме бегущей волны в широком диапазоне частот на одном периоде структуры в трехмерном приближении для опорного набора набегов фазы поля на период. Для структуры с произвольным числом периодов ВМК параметры интерполируются исходя из свойств периодичности. Разрешение метода не зависит от числа периодов в структуре и позволяет выявить важные особенности ВМК в длинных структурах и диапазоне высоких частот.ВЧ-характеристики вищих мод коливань (ВМК) розраховані в режимі бігучої хвилі в широкому діапазоні частот на одному періоді структури в тривимірному наближенні для опорного набору набігів фази поля на період. Для структури з довільним числом періодів ВМК параметри інтерполіруються виходячи з властивостей періодичності. Дозвіл методу не залежить від числа періодів в структурі і дозволяє виявити важливі особливості ВМК у довгих структурах і діапазоні високих частот

    Mathematical software for the synthesis of domestic catalyst of ethylene acetoxylation process

    Get PDF
    We have created a mathematical model of the catalyst carrier of the process of ethylene acetoxylation for synthesis of vinyl acetate take into account the physical parameters of the catalyst carrier and chemical composition of the catalyst. We have solved the following problems: the problem of optimization of the physical parameters of the catalyst carrier; the problem of multi-objective constrained optimization of chemical composition of the catalyst. This optimization allows maximizing the selectivity and the activity of the catalyst and minimizing the content of gold and palladium. These problems have been solved through nonlinear programming methods

    CLINICAL AND IMMUNOLOGICAL PECULIARITIES OF INFLAMMATORY PERIODONTAL DISEASES IN PREGNANT WOMEN ON THE BACKGROUND OF IRON DEFECTIVE ANEMIA

    Get PDF
    The gingival fluid of pregnant women was studied for interleukins 8 and 10, and immunoglobulins A and G in 31 female patients of SHI CH No.5 of Volgograd, at the age of 20-25 years - the first period of adulthood (Iordanishvili A.K., 2015), 15 of which - without IDA, and 16 - with manifestations of IDA. Treatment of mild and moderate periodontitis (K05.3) was carried out in pregnant women with IDA with the use of Lysobact; pregnant women without IDA were treated with traditional anti-inflammatory therapy according to the treatment algorithm. In both groups, professional oral hygiene, active training and monitoring of the performance of individual hygiene were carried out. It was established that the concentration of IL-10 increases significantly (p <0.05) from 0.010 [1.790] ng/ml to 3.050 [8.550] ng/ml after treatment, against the background of complex treatment of periodontitis in pregnant women with IDA with Lysobact. This confirms the importance of interleukin 10 as the main anti-inflammatory cytokine and objectively proves the correctness of the selected clinical tactics for treating mild and moderate inflammatory periodontal diseases with the drug "Lysobact" against the background of iron deficiency anemia. Keywords: pregnant women, iron deficiency anemia, periodontal disease

    Triangle Singularity as the Origin of the a1(1420)

    No full text
    International audienceThe COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a1(1420), decaying to f0(980)π. With a mass too close to and a width smaller than the axial-vector ground state a1(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a1(1260) resonance into K*(→Kπ)K¯ and subsequent rescattering through a triangle singularity into the coupled f0(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect

    Spin density matrix elements in exclusive ρ0\rho ^0 meson muoproduction

    No full text
    We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive ρ0\rho ^0 meson muoproduction at COMPASS using 160~GeV/cc polarised μ+ \mu ^{+} and μ \mu ^{-} beams impinging on a liquid hydrogen target. The measurement covers the kinematic range 5.0~GeV/c2c^2 <W<< W < 17.0~GeV/c2c^2, 1.0 (GeV/cc)2^2 <Q2<< Q^2 < 10.0 (GeV/cc)2^2 and 0.01 (GeV/cc)2^2 <pT2<< p_{\rm{T}}^2 < 0.5 (GeV/cc)2^2. Here, WW denotes the mass of the final hadronic system, Q2Q^2 the virtuality of the exchanged photon, and pTp_{\rm{T}} the transverse momentum of the ρ0\rho ^0 meson with respect to the virtual-photon direction. The measured non-zero SDMEs for the transitions of transversely polarised virtual photons to longitudinally polarised vector mesons (γTVL\gamma^*_T \to V^{ }_L) indicate a violation of ss-channel helicity conservation. Additionally, we observe a dominant contribution of natural-parity-exchange transitions and a very small contribution of unnatural-parity-exchange transitions, which is compatible with zero within experimental uncertainties. The results provide important input for modelling Generalised Parton Distributions (GPDs). In particular, they may allow one to evaluate in a model-dependent way the role of parton helicity-flip GPDs in exclusive ρ0\rho ^0 production.We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive ρ0\rho ^0 meson muoproduction at COMPASS using 160 GeV/c polarised μ+ \mu ^{+} and μ \mu ^{-} beams impinging on a liquid hydrogen target. The measurement covers the kinematic range 5.0 GeV/c2<W<c^2< W< 17.0 GeV/c2c^2, 1.0 (GeV/c)2<Q2<^2< Q^2< 10.0 (GeV/c)2^2 and 0.01 (GeV/c)2<pT2<^2< p_{\textrm{T}}^2< 0.5 (GeV/c)2^2. Here, W denotes the mass of the final hadronic system, Q2Q^2 the virtuality of the exchanged photon, and pTp_{\textrm{T}} the transverse momentum of the ρ0\rho ^0 meson with respect to the virtual-photon direction. The measured non-zero SDMEs for the transitions of transversely polarised virtual photons to longitudinally polarised vector mesons (γTVL\gamma ^*_T \rightarrow V^{ }_L) indicate a violation of s-channel helicity conservation. Additionally, we observe a dominant contribution of natural-parity-exchange transitions and a very small contribution of unnatural-parity-exchange transitions, which is compatible with zero within experimental uncertainties. The results provide important input for modelling Generalised Parton Distributions (GPDs). In particular, they may allow one to evaluate in a model-dependent way the role of parton helicity-flip GPDs in exclusive ρ0\rho ^0 production.We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive ρ0\rho ^0 meson muoproduction at COMPASS using 160~GeV/cc polarised μ+ \mu ^{+} and μ \mu ^{-} beams impinging on a liquid hydrogen target. The measurement covers the kinematic range 5.0~GeV/c2c^2<W<< W < 17.0~GeV/c2c^2, 1.0 (GeV/cc)2^2<Q2<< Q^2 < 10.0 (GeV/cc)2^2 and 0.01 (GeV/cc)2^2<pT2<< p_{\rm{T}}^2 < 0.5 (GeV/cc)2^2. Here, WW denotes the mass of the final hadronic system, Q2Q^2 the virtuality of the exchanged photon, and pTp_{\rm{T}} the transverse momentum of the ρ0\rho ^0 meson with respect to the virtual-photon direction. The measured non-zero SDMEs for the transitions of transversely polarised virtual photons to longitudinally polarised vector mesons (γTVL\gamma^*_T \to V^{ }_L) indicate a violation of ss-channel helicity conservation. Additionally, we observe a dominant contribution of natural-parity-exchange transitions and a very small contribution of unnatural-parity-exchange transitions, which is compatible with zero within experimental uncertainties. The results provide important input for modelling Generalised Parton Distributions (GPDs). In particular, they may allow one to evaluate in a model-dependent way the role of parton helicity-flip GPDs in exclusive ρ0\rho ^0 production

    Exotic meson π1(1600)\pi_1(1600) with JPC=1+J^{PC} = 1^{-+} and its decay into ρ(770)π\rho(770)\pi

    No full text
    International audienceWe study the spin-exotic JPC=1-+ amplitude in single-diffractive dissociation of 190  GeV/c pions into π-π-π+ using a hydrogen target and confirm the π1(1600)→ρ(770)π amplitude, which interferes with a nonresonant 1-+ amplitude. We demonstrate that conflicting conclusions from previous studies on these amplitudes can be attributed to different analysis models and different treatment of the dependence of the amplitudes on the squared four-momentum transfer and we thus reconcile these experimental findings. We study the nonresonant contributions to the π-π-π+ final state using pseudodata generated on the basis of a Deck model. Subjecting pseudodata and real data to the same partial-wave analysis, we find good agreement concerning the spectral shape and its dependence on the squared four-momentum transfer for the JPC=1-+ amplitude and also for amplitudes with other JPC quantum numbers. We investigate for the first time the amplitude of the π-π+ subsystem with JPC=1-- in the 3π amplitude with JPC=1-+ employing the novel freed-isobar analysis scheme. We reveal this π-π+ amplitude to be dominated by the ρ(770) for both the π1(1600) and the nonresonant contribution. These findings largely confirm the underlying assumptions for the isobar model used in all previous partial-wave analyses addressing the JPC=1-+ amplitude

    Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of ρ0\rho^0 mesons

    No full text
    The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related phenomena. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced ρ0\rho^0 mesons. The analysis is based on the data set collected in deep inelastic scattering in 20102010 using a 160GeV/c160\,\,\rm{GeV}/c μ+\mu^+ beam impinging on a transversely polarized NH3\rm{NH}_3 target. The ρ0\rho^{0} mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-xx variable, the transverse momentum of the pair and the fraction of the energy zz carried by the pair. Indications for positive Collins and Sivers asymmetries are observed.The production of vector mesons in deep inelastic scattering is an interesting yet scarcely explored channel to study the transverse spin structure of the nucleon and the spin-dependence of fragmentation. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced ρ0 mesons. The analysis is based on the data set collected in deep inelastic scattering in 2010 using a 160GeV/cμ+ beam impinging on a transversely polarized NH3 target. The ρ0 mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-x variable, the transverse momentum of the pair and the fraction of the energy z carried by the pair. Indications for positive Collins and Sivers asymmetries are observed.The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related phenomena. The COMPASS collaboration has performed the first measurement of the Collins and Sivers asymmetries for inclusively produced ρ0\rho^0 mesons. The analysis is based on the data set collected in deep inelastic scattering in 20102010 using a 160GeV/c160\,\,\rm{GeV}/cμ+\mu^+ beam impinging on a transversely polarized NH3\rm{NH}_3 target. The ρ0\rho^{0} mesons are selected from oppositely charged hadron pairs, and the asymmetries are extracted as a function of the Bjorken-xx variable, the transverse momentum of the pair and the fraction of the energy zz carried by the pair. Indications for positive Collins and Sivers asymmetries are observed

    Transverse-spin-dependent azimuthal asymmetries of pion and kaon pairs produced in muon-proton and muon-deuteron semi-inclusive deep inelastic scattering

    No full text
    A set of measurements of azimuthal asymmetries in the production of pairs of identified hadrons in deep-inelastic scattering of muons on transversely polarised 6LiD (deuteron) and NH3 (proton) targets is presented. All available data collected in the years 2003–2004 and 2007/2010 with the COMPASS spectrometer using a muon beam of 160GeV/c at the CERN SPS were analysed. The asymmetries provide access to the transversity distribution functions via a fragmentation function that in principle may be independently obtained from e+e− annihilation data. Results are presented, discussed and compared to existing measurements as well as to model predictions. Asymmetries of π+π− pairs measured with the proton target as a function of the Bjorken scaling variable are sizeable in the range x>0.032, indicating non-vanishing transversity distribution and di-hadron interference fragmentation functions. As already pointed out by several authors, the small asymmetries of π+π− measured on the 6LiD target can be interpreted as indication for a cancellation of u and d-quark transversity distributions

    Antiproton over proton and K^- over K+^+ multiplicity ratios at high zz in DIS

    No full text
    International audienceThe antiparticle-over-particle multiplicity ratio is measured in deep-inelastic scattering for negatively and positively charged kaons and, for the first time, for antiprotons and protons. The data were obtained by the COMPASS Collaboration using a 160 GeV muon beam impinging on an isoscalar 6 LiD target. The regime of deep-inelastic scattering is ensured by requiring Q2 > 1 (GeV/ c ) 2 for the photon virtuality and W>5 GeV/ c2 for the invariant mass of the produced hadronic system. Bjorken- x is restricted to the range 0.01 to 0.40. Protons and antiprotons are identified in the momentum range from 20 GeV/ c to 60 GeV/ c and required to carry a large fraction of the virtual-photon energy, z>0.5 . In the whole studied z -region, the p¯ over p multiplicity ratio is found to be below the lower limit expected from calculations based on leading-order perturbative Quantum Chromodynamics (pQCD). Kaons were previously analysed in the momentum range 12 GeV/ c to 40 GeV/ c . In the present analysis this range is extended up to 55 GeV/ c , whereby events with larger virtual-photon energies are included in the analysis and the observed K − over K + ratio becomes closer to the expectation of next-to-leading order pQCD. The results of both analyses strengthen our earlier conclusion that at COMPASS energies the phase space available for single-hadron production in deep-inelastic scattering should be taken into account in the standard pQCD formalism
    corecore