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.
The thermal and mechanical tests of different porosity limestone show that an increase in the axial load results in the higher velocities of elastic waves while elevation of temperature decreases ...them. Higher temperatures act to raise velocities of P- and S-waves with increasing mechanical load, which enhances acoustic strain-sensitivity of rock. The spectral analysis of the recorded signals shows that higher temperature shifts spectrum maxima to lower frequency region. It is found that size of pores has influence on attenuation frequency of ultrasonic signals. The authors describe new approaches to acoustic strain-sensitivity control in rocks and to stress measurement reliability enhancement toward stability of underground structures.
Iatrogenic glossopharyngeal nerve injuries are commonly associated with procedures such as a tonsillectomy, carotid endarterectomy, and endotracheal intubation. We present a previously unreported ...complication of a thread lift procedure in the jowl region, causing damage to the glossopharyngeal nerve through compression. The glossopharyngeal nerve belongs to the bulbar group of the cranial nerves. It is connected with the vagus and, therefore, is closely associated with the latter functionally and anatomically. Damage to the former may present with cardiovascular complications associated with the vagus nerve. The presented case demonstrates the diagnostic and treatment aspects of iatrogenic injury to the glossopharyngeal nerve.
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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.
We propose an 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. The ...search method is based on a missing mass spectrum in the 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 the coupling constant ϵ2=3ċ10−8 with a signal-to-noise ratio of two to one at an A' mass of 5–20 MeV .
In the mid-20th century, the first case of infection of European bees Apis mellifera L. with the ectoparasite mite Varroa destructor was recorded. The original host of this mite is the Asian bee Apis ...cerana. The mite V. destructor was widespread throughout Europe, North and South America, and Australia remained the only continent free from this parasite. Without acaricide treatment any honeybee colony dies within 1-4 years. The use of synthetic acaricides has not justified itself - they make beekeeping products unsuitable and mites develop resistance to them, which forces the use of even greater concentrations that can be toxic to the bees. Therefore, the only safe measure to combat the mite is the use of biological control methods. One of these methods is the selection of bee colonies with natural mite resistance. In this article we summarize publications devoted to the search for genetic markers associated with resistance to V. destructor. The first part discusses the basic mechanisms of bee resistance (Varroa sensitive hygienic behavior and grooming) and methods for their assessment. The second part focuses on research aimed at searching for loci and candidate genes associated with resistance to varroosis by mapping quantitative traits loci and genome-wide association studies. The third part summarizes studies of the transcriptome profile of Varroa resistant bees. The last part discusses the most likely candidate genes - potential markers for breeding Varroa resistant bees. Resistance to the mite is manifested in a variety of phenotypes and is under polygenic control. The establishing of gene pathways involved in resistance to Varroa will help create a methodological basis for the selection of Varroa resistant honeybee colonies.
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.
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.
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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