The ratio of the electron and muon widths of the J/ psi J/ psi meson has been measured using direct J/ psi J/ psi decays in the KEDR experiment at the VEPP-4M electron-positron collider. The result ...Gamma e+e-(J/ psi )/ Gamma mu + mu -(J/ psi )=1.0022 plus or minus 0.0044 plus or minus 0.0048(0.65%) is in good agreement with the lepton universality. The experience collected during this analysis will be used for J/ psi J/ psi lepton width determination with up to 1% accuracy.
Measurement of parameters Anashin, V V; Aulchenko, V M; Baldin, E M ...
Physics letters. B,
05/2012, Letnik:
711, Številka:
3-4
Journal Article
Recenzirano
We report the final results of a study of the psi ( 3770 ) meson using a data sample collected with the KEDR detector at the VEPP-4M electron-positron collider. The data analysis takes into account ...interference between the resonant and nonresonant D D macr production, where the latter is related to the nonresonant part of the energy-dependent form factor F D . The vector dominance approach and several empirical parameterizations have been tried for the nonresonant F D N R ( s ) . Our results for the mass and total width of psi ( 3770 ) are M = 3779.2 - 1.7 + 1.8 - 0.7 + 0.5 - 0.3 + 0.3 MeV , Gamma = 24.9 - 4.0 + 4.6 - 0.6 + 0.5 - 0.9 + 0.2 MeV , where the first, second and third uncertainties are statistical, systematic and model, respectively. For the electron partial width two possible solutions have been found: ( 1 ) Gamma e e = 154 - 58 + 79 - 9 + 17 - 25 + 13 eV , ( 2 ) Gamma e e = 414 - 80 + 72 - 26 + 24 - 10 + 90 eV . Our statistics are insufficient to prefer one solution to another. The Solution (2) mitigates the problem of non- D D macr decays but is disfavored by potential models. It is shown that taking into account the resonance-continuum interference in the near-threshold region affects resonance parameters, thus the results presented cannot be directly compared with the corresponding PDG values obtained ignoring this effect.
A high-precision determination of the main parameters of the psi ( 2 S ) resonance has been performed with the KEDR detector at the VEPP-4M e + e - collider in three scans of the psi ( 2 S ) - psi ( ...3770 ) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the psi ( 2 S ) we obtained the mass value M = 3686.114 plus or minus 0.007 plus or minus 0.011 - 0.012 + 0.002 MeV and the product of the electron partial width by the branching fraction into hadrons Gamma e e B h = 2.233 plus or minus 0.015 plus or minus 0.037 plus or minus 0.020 keV . The first and second uncertainties are statistical and systematic, respectively. The third uncertainty quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e + e - annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the psi ( 2 S ) : Gamma e e = 2.282 plus or minus 0.015 plus or minus 0.038 plus or minus 0.021 keV , Gamma = 296 plus or minus 2 plus or minus 8 plus or minus 3 keV . These results are consistent with and more than two times more precise than any of the previous experiments.
We report results of a search for narrow resonances in e super(+e) super(-) annihilation at center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR detector at the VEPP-4M e ...super(+e) super(-) collider. The upper limit on the leptonic width of a narrow resonance inline image has been obtained (at 90% C.L.).
This volume delves into a key part of the comprehensive Russian administrative and territorial reform of the 2000s—the merger of six previously separate ethno-national regions into larger constituent ...entities of the Russian Federation. It deals with the accession of the Komi-Permyak, Taymyr Dolgano-Nenets, Evenk, Agin-Buryat, and Koryak Autonomous Okrugs to the Perm, Krasnoyarsk, Zabaykalsky, and Kamchatka Krais, and of the Ust-Orda Buryat Autonomous Okrug to the Irkutsk Oblast. In both management practice and mass media, the largely similar unifications were treated as unrelated initiatives emerging from inside the regions. The center did initially not offer a common institutional model of integration. The regions had to come up with individual formulas dealing with the merged districts. After the reform had slowed down, it turned out that the annexed territories had only in name obtained special statuses which are not backed by administrative or financial resources. The book addresses specialists in the fields of Russian studies, comparative federalism, and ethnic politics. It makes an especially important reading because it describes and thoroughly analyzes the unique deautonomization case in an ethnic federation. Additional contributors to this volume are Maria Tislenko, Emma Bibina, and Rostislav Shilovsky (all MGIMO University).
•Dynamics of methanol ad/desorption of commercial carbon ACM-35 is studied.•Dynamics initiated by fast temperature or pressure changes are compared.•Monolayer and multi-layer configurations of carbon ...grains are studied.•For monolayer configuration, the dynamics does not depend on the initiation way.
Despite significant progress made in adsorption heat transformation, still, there is a big room for it's further improving. This work addresses the dynamic study of methanol adsorption and comparison of two ways of the process initiation. The traditional way is due to fast temperature change (TI), and the less studied one is by quick pressure variation (PI). The appropriate temperature/pressure variations were selected similar to those in a new cycle “Heat from Cold” recently suggested for upgrading the ambient heat in cold countries. An activated carbon ACM-35.4, used as a methanol adsorbent, was located on metal support as a thin flat bed of loose grains.
For a monolayer bed configuration, the dynamics is almost identical for the two initiation ways. Both TI and PI kinetic curves are exponential with a characteristic time, which depends on the process boundary conditions rather than the initiation mode. The mathematical model of methanol adsorption on a single spherical carbon grain is developed to explain these results.
The perceptible difference is found for the multi-layer configuration of the carbon bed. The PI adsorption dynamics is faster than the TI one at short adsorption time and equal to it at long time. A possible reason for this difference is discussed.
In this work, a series of K2CO3-containing composite materials based on alumina supports with different porous structure were synthesized and studied in a direct air capture process. Alumina supports ...with the modified porous structure were obtained as a result of the thermal treatment of porous γ-Al2O3 at elevated temperatures. Composite materials were synthesized by impregnating the porous support (unmodified or modified alumina) with an aqueous solution of potassium carbonate. All the K2CO3/Al2O3 sorbents were tested in the process of CO2 absorption from the air with a relative humidity of 25% followed by thermal desorption as a result of heating the material to 200 °C. The composite materials were characterized by X-ray diffraction and temperature-programmed desorption methods. Among the materials studied, the composite sorbent based on the porous alumina thermally modified at T = 750 °C demonstrated the highest dynamic CO2 absorption capacity. This composite material was later tested in a direct air capture/methanation process combining CO2 capture from ambient air and methanation via the catalytic Sabatier reaction. The process was implicated using an adsorber and a catalytic reactor connected in series. To regenerate the composite sorbent after the step of CO2 absorption from ambient air, the adsorber was heated to 200 °C in an H2 flow. The desorbed CO2 was converted into methane in the preheated catalytic reactor containing the Ru/Al2O3 methanation catalyst. The optimization of the operating conditions (namely, the catalytic reactor temperature and the inlet H2 flow rate) allowed for obtaining CH4 from carbon dioxide with a yield of 98%. The thermal energy required for heating the new CO2 sorbent from 25 to 200 °C at the desorption/methanation step of the direct air capture/methanation process was estimated to be 9 MJ per 1 m3 (STP) of produced CH4.
Pollution of soils with arsenic leads to changes in biochemical processes both in the soil and in plants growing on it. Biochemically active compounds, such as free amino acids, strongly respond to ...the increase of the content of toxic substances in the environment. This article deals with the changes in the concentration of free amino acids in soil, roots, and aboveground biomass of tomato plants that took place when soil was contaminated with arsenic. Pre-grown tomato plants (
Solanum lycopersicum
L.) were transplanted into containers with soil contaminated with arsenate (As(V)) at the doses of 50 and 200 mg kg
−1
. In the soils, roots, and aboveground parts of plants, the changes in the concentration of 16–17 free amino acids were studied by the method of high-performance liquid chromatography. The results of the experiment showed that soil contamination with arsenic can lead to an increase in the concentration of all studied amino acids, both in soils and in tomato plants. Total free amino acid concentration in soil increased by 194.2% at 50 mg kg
−
1
of As(V) and by 349.6% at 200 mg kg
−1
of As(V), in roots and aboveground biomass their concentration increased from 1.5 to 4.6 times. A particularly strong increase of concentration in soil was observed for serine and glycine, whereas in plant tissues, in comparison with other amino acids, aspartic and glutamic acids were intensively accumulated. The strong correlation between the content of free amino acids in the soils and in the roots (
r
= 0.85) or aboveground biomass of plants (
r
= 0.88) shows that both soil and tomato plants respond to soil contamination with As(V) in a similar way. However, the results of the study also showed that increasing of amino acid concentration in plant tissues in case of arsenic contamination can be associated with both their accumulations due to the plant’s response to stressful conditions and probably their uptake from the soil.
Abstract
We study the evolution of angular variable (phase) for general (not necessarily Hamiltonian) perturbations of Hamiltonian systems with one degree of freedom near separatrices of the ...unperturbed system. To this end, we use the averaged system of order 2. We obtain estimates for the accuracy of the order 2 averaged system near separatrices and use these estimates to prove a formula for the phase change when solutions of the perturbed system approach separatrices of the unperturbed system (such formula is known when the perturbation is Hamiltonian). As an application of this formula, we show that two natural definitions of probability of capture into different domains after separatrix crossing proposed by Arnold and Anosov lead to the same formula for this probability.
PDF
