The Super Charm-Tau Factory project proposed at Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, in Novosibirsk is discussed. An electron–positron collider with the ...luminosity of
cm
s
and energies of 2 to 6 GeV in the beam center-of-mass frame and with a state-of-the-art particle detector arranged at the point of
interaction will permit studying, at a new precision level, the physics of charmonium, exotic charmonium-like states, charmed mesons and baryons, and the tau lepton, as well as the production of light hadrons in
-annihilation processes and in two-photon processes. A longitudinal polarization of the electron beam at the interaction point will provide a number of competitive advantages to the Super Charm-Tau Factory in relation to Super B factories such as Belle II and LHCb.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We present a study of Michel parameters in leptonic τ decays using experimental information collected at the Belle detector. Michel parameters are extracted in the unbinned maximum likelihood fit of ...the (τ∓→ℓ∓νν; τ±→π±π0ν) (ℓ=e, μ) events in the full nine-dimensional phase space. We exploit the spin-spin correlation of tau leptons to extract ξρξ and ξρξδ in addition to the ρ and η parameters. Sensitivity of the method and systematic effects will be discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
3.
Experiments at the Super Charm-Tau factory Achasov, Mikhail N.; Blinov, Vladimir E.; Bobrov, Alexander V. ...
Physics Uspekhi,
01/2024, Volume:
67, Issue:
1
Journal Article
An apparatus is described that allows studying various physical and chemical processes in the atmosphere of supercritical carbon dioxide at pressures of up to 25 MPa and temperatures of up to 100°C. ...The apparatus is based on a compact modular cylindrical high-pressure reactor with a diameter of 90 mm and a height of 100 mm with an internal volume of 14 cm
3
. It is equipped with eight optical ports, a system for measuring and adjusting the pressure and temperature, as well as a system for letting in and gradually reducing the pressure of the test medium. In addition, the reactor is equipped with two video cameras with a resolution of 1920 × 1080 pixels, which allow video recording of processes occurring in the reactor volume, which is synchronized with the pressure and temperature data recording system. The efficiency of the described apparatus is demonstrated by studying the processes of plasticization and foaming of polymer materials in the medium of supercritical carbon dioxide.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The paper presents a current status of the simulation of the pure CsI crystal calorimeter of the detector of charm-tau factory project in Novosibirsk. The calorimeter employs the scheme with the ...crystals focusing at the beams interaction point to obtain the optimal energy and coordinate resolutions. We present a detailed description of the calorimeter design, optimized using the specially developed parametrized crystal geometry generator. The report also presents the results for the coordinate and energy correction functions calculation. After application of these corrections the estimation of the photon energy and coordinate resolutions for the ideal conditions of negligibly small stochastic, electronic and pileup noises was performed. The π0 reconstruction efficiency and mass resolution depending on it's momentum were also determined.
Abstract
A laboratory system for the development of new approaches to the experimental study of nucleation and formation of three-dimensional structures in nonequilibrium “polymer-supercritical ...fluid” heterogeneous systems has been designed and produced. The system is designed to conduct a comprehensive analysis of these processes at various stages starting from supercritical fluid plasticization of the initial polymer, followed by its subsequent nucleation and passage to the glass transition stage of the foamed polymer matrix, providing an opportunity for adequate interpretation.
A
bstract
The cross section of the process
e
+
e
−
→ ηπ
+
π
−
is measured using the data collected with the CMD-3 detector at the VEPP-2000 collider in the center-of-mass energy range from 1
.
1 to 2
....
0 GeV. The decay mode
η → γγ
is used for
η
meson reconstruction in the data sample corresponding to an integrated luminosity of 78
.
3 pb
−
1
. The energy dependence of the
e
+
e
−
→ ηπ
+
π
−
cross section is fitted within the framework of vector meson dominance in order to extract the Γ(
ρ
(1450)
→ e
+
e
−
)
B
(
ρ
(1450)
→ ηπ
+
π
−
) and the Γ(
ρ
(1700)
→ e
+
e
−
)
B
(
ρ
(1700)
→ ηπ
+
π
−
) products. Based on conservation of vector current, the analyzed data are used to test the relationship between the
e
+
e
−
→ ηπ
+
π
−
cross section and the spectral function in
τ
−
→ ηπ
−
π
0
ντ
decay. The
e
+
e
−
→ ηπ
+
π
−
cross section obtained with the CMD-3 detector is in good agreement with the previous measurements.
The article discusses the acute problem of regulating the turnover of disposable plastic items in the Russian Federation. The goal of elaborating the system of manufacturing, recycling and utilizing ...plastic goods is connected with the necessity to improve ecological security and to combat locating huge volumes of solid municipal waste at landfill sites in the country, the majority of them are already overfilled and their extension is not possible. In 2019 the President of Russia set the goal of developing the system of recycling and utilizing wastes, however large-scale solutions have not been implemented yet. Economic policy developers often interpret this task as the necessity to impose fines on manufacturing and turnover of certain types of disposable goods and packages, which is not always effective. The article underlines the importance of the problem, researches and systematizes approaches, which can be used to shape economic policy in Russia. Apart from that, it describes alternative opportunities of reducing volumes of wastes difficult for extraction during sorting, which should be included in the system providing closed cycle manufacturing, which is not finished with product shipping but requires waste recycling.
A scintillation counter consisting of a pure CsI crystal and avalanche photodiodes (Hamamatsu APD S8664-55 and S8664-1010) has been studied for the upgrade of the end cap electromagnetic calorimeter ...of Belle II detector. An essential increase of the light output was achieved with wavelength shifters based on nanostructured organosilicon luminophores.
•A scintillation counter consisting of a pure CsI crystal and avalanche photodiodes has been studied.•The equivalent noise charge and equivalent noise energy of the counter have been measured.•An essential increase of the light output was achieved with wavelength shifters.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The mechanisms that control the nucleation kinetics in foamed amorphous D,L-polylactide, which was preliminary plasticized using subcritical or supercritical carbon dioxide, were determined by ...analyzing the video data on the depressurization-induced quasi-isothermal (313.3 K) foaming of the polymer. Possible scenarios of phase separation in the polylactide–carbon dioxide system at the stage preceding active foam formation were considered.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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