The ratio of the elastic e(+)p to e(-)p scattering cross sections has been measured precisely, allowing the determination of the two-photon exchange contribution to these processes. This neglected ...contribution is believed to be the cause of the discrepancy between the Rosenbluth and polarization transfer methods of measuring the proton electromagnetic form factors. The experiment was performed at the VEPP-3 storage ring at beam energies of 1.6 and 1.0 GeV and at lepton scattering angles between 15° and 105°. The data obtained show evidence of a significant two-photon exchange effect. The results are compared with several theoretical predictions.
This paper examines the distinctive features of the pricing system when planning and carrying out overhaul in multi-apartment residential buildings. The authors analyzed the data posted in public ...resources, after which they were optimized in terms of sufficiency for further research. Due to the qualitative heterogeneity of the data, a unified unit of measure was proposed and introduced for the present value of the overhaul works. To select data and determine their stable relationships in a series, calculations of absolute and relative indicators of variation were performed. The results of the study showed that the coefficient of variation of the average present costs of overhaul of apartment buildings within the framework of the totality of the constituent entities of the Russian Federation is equally homogeneous and heterogeneous for various types of work. It was found that for certain types of work, cost indicators have a stable average, while for others it is impossible to single out this indicator.
The article lists the main reasons for reducing the dust extraction systems' efficiency. The general principle of experiment planning is described. The use of a mixed fractional factorial plan with ...four factors at two levels and with two factors at three levels of variation is justified when using the shutters available in the dust extraction system. The condition that there is no need to exclude the insignificant factors (from the point of view of technical experiments), is established.
Abstract
The article deals with the aspectology of determining the classification of problems in the metrological apparatus of medical support. Attention is paid to the design and synthesis of the ...principles of diagnostics and direct measurements in medicine. The functional and semantic component of modern computer diagnostic methods is indicated, their synergistic effect is determined. The importance of promising measurement control methods - expert systems of new generations is substantiated. The author’s consideration of the issue of solving specific problems through the methods of artificial intelligence and information technologies in mass spectroscopy is given.
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A cryogenic source of polarized deuterium atoms is described. This source is used in the experiment on measuring the analyzing powers in the deuteron photodisintegration reaction at the VEPP-3 ...electron storage ring at the Budker Institute of Nuclear Physics. The efficiency has been measured for atomic transitions to a specified energy state in the medium field transition (MFT) unit, in the strong field transition (SFT) unit, and for joint operation of these units. A Lamb shift polarimeter was used in the measurements. The measured efficiency of the units is over 90%. The procedure for determining the background in the polarimeter is presented. The use of pumping in the ionizer chamber is expected to significantly reduce the background signal.
This paper describes a new multipurpose event generator, ESEPP, which has been developed for the Monte Carlo simulation of unpolarized elastic scattering of charged leptons on protons. The generator ...takes into account the lowest-order QED radiative corrections to the Rosenbluth cross section including first-order bremsstrahlung without using the soft-photon or ultrarelativistic approximations. ESEPP can be useful for several significant ongoing and planned experiments.
New results have been presented for the
T
20
component of the tensor analyzing power of the γ
d
→
pp
π
–
reaction measured in the photon energy range from 300 to 600 MeV. The data have been obtained ...from the statistical sample collected at the VEPP-3 accelerator in 2021. The
T
20
component has been separated using the asymmetry of the reaction yield, which is due to change in the sign of the tensor polarization of the deuterium target. The experimental data have been compared to the simulation within the spectator model including the interaction between particles in the final state.
The status of the experiment to search for a new gauge boson, A′, in e+e− annihilation by means of a positron beam incident on a gas hydrogen target internal to the bypass at the VEPP-3 storage ring ...is reported. The search method is based on a missing mass spectra in reaction e+e− → γA′. It allows observation of the A′ signal independently of its decay modes and life time. The projected result of this experiment corresponds to an upper limit on the square of coupling constant ε2 = (0.2 ÷ 1.0) · 10−7 with a signal-to-noise ratio of two to one at A′ mass of 5–20 MeV.
Filling of single-walled carbon nanotubes (SWCNTs) and extraction of the encapsulated species from their cavities are perspective treatments for tuning the functional properties of SWCNT-based ...materials. Here, we have investigated sulfur-modified SWCNTs synthesized by the ampoule method. The morphology and chemical states of carbon and sulfur were analyzed by transmission electron microscopy, Raman scattering, thermogravimetric analysis, X-ray photoelectron and near-edge X-ray absorption fine structure spectroscopies. Successful encapsulation of sulfur inside SWCNTs cavities was demonstrated. The peculiarities of interactions of SWCNTs with encapsulated and external sulfur species were analyzed in details. In particular, the donor-acceptor interaction between encapsulated sulfur and host SWCNT is experimentally demonstrated. The sulfur-filled SWCNTs were continuously irradiated
with polychromatic photon beam of high intensity. Comparison of X-ray spectra of the samples before and after the treatment revealed sulfur transport from the interior to the surface of SWCNTs bundles, in particular extraction of sulfur from the SWCNT cavity. These results show that the moderate heating of filled nanotubes could be used to de-encapsulate the guest species tuning the local composition, and hence, the functional properties of SWCNT-based materials.
Abstract
In this article a short overview of current micro-pattern gaseous detectors development and applications at Budker Institute of Nuclear Physics is presented. The triple-GEM detector for the ...Laser Polarimeter facility and the end-cap discs for the upgrade of the CMD-3 detector are considered in more details.
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