Searches for the process of electron–positron (
) annihilation to the
(2007)
meson were performed by means of the CMD-3 detector at the VEPP-2000
collider. In the data analysis, use was made of two ...dominant modes of
-meson decay to
and
, where
was reconstructed in the
channel. By employing a 3.7 pb
data sample accumulated at the c.m. energy of
MeV, an upper bound of
on the decay branching ratio was obtained at a
confidence level.
A preliminary result of an analysis of the process
whose cross section was measured in the range of center-of-mass collision energies between 1.2 and 2 GeV is presented. The analysis is based on the ...data sample corresponding to an integrated luminosity of about 120 pb
accumulated with the CMD-3 detector at the VEPP-2000 electron–positron collider. A procedure for separating signal events is developed, and the dominance of the
neutral mode is confirmed. The cross section for the process
is measured to a precision higher than that in earlier experiments. This permits improving the accuracy in measuring the mass and width of the
(1680) meson, testing the accuracy of the isotopic relations, and more accurately calculating the hadronic contribution to the muon anomalous magnetic moment (
).
The aim
of the work was to determine the effective ultraviolet (UV) doses required for the disinfection of surfaces contaminated with the SARS-CoV-2 coronavirus using a low-pressure mercury lamp.
...Materials and methods
. To carry out prompt disinfection of surfaces, a specially designed source of UV radiation with a power of 7.5 W at a wavelength of 254 nm in the form of a portable flashlight was employed, which has a high efficiency of UV radiation output and the possibility of long-term autonomous operation from a compact battery. In the studies, a suspension culture of the SARS-CoV-2 coronavirus with biological activity of 5.3∙10
6
PFU/ml was used. The objects of testing were plastic Petri dishes (disposable) and office paper (grade C, density 80 g/m
2
).
Results and discussion
. Doses of UV radiation that provide disinfection of surfaces contaminated with the COVID-19 pathogen with an efficiency of 99.0 % (paper) to 99.95 % (plastic) have been determined. The results obtained make it possible to recommend a portable UV irradiator for use in the practice of preventive measures to combat the spread of the disease caused by the SARS-CoV-2 coronavirus.
Barrel calorimeter of the CMD-3 detector Anisenkov, A.V.; Aulchenko, V.M.; Barkov, L.M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
732
Journal Article
Recenzirano
Since 2010 the CMD-3 detector has been collecting data at the e+e− collider VEPP-2000 at Budker Institute of Nuclear Physics. CMD-3 is a general purpose detector designed to study e+e− annihilation ...into hadrons in the wide energy range s=0.3–2GeV. The CMD-3 barrel electromagnetic calorimeter consists of two subsystems: closest to the beam pipe is the Liquid Xenon calorimeter and the outer one is based on CsI scintillation crystals. The design of the calorimeter and its current performance are presented.
The paper describes a method of the charged particle identification, developed for the CMD-3 detector, installed at the VEPP-2000 e+e− collider. The method is based on application of boosted decision ...trees classifiers, trained for the optimal separation of electrons, muons, pions and kaons in the momentum range from 100 to 1200MeV/c. The input variables for the classifiers are linear combinations of the energy depositions of charged particles in 12 layers of the liquid xenon calorimeter of the CMD-3. The event samples for training of the classifiers are taken from the simulation. Various issues of the calorimeter strip channels response simulation and their calibration are considered. Application of the method is illustrated by the examples of separation of the e+e−(γ) and π+π−(γ) final states and of selection of the K+K− final state at high energies.
The cross section of the process e + e − → π + π − has been measured in the center-of-mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The ...measurement is based on an integrated luminosity of about 88 pb − 1 , of which 62 pb − 1 represent a complete dataset collected by CMD-3 at center-of-mass energies below 1 GeV. In the dominant region near the ρ resonance a systematic uncertainty of 0.7% was achieved. The implications of the presented results for the evaluation of the hadronic contribution to the anomalous magnetic moment of the muon are discussed. Published by the American Physical Society 2024
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