There exists a great deal of concrete evidence in favor of the exotic four-quark nature of light scalars. At the same time, the further expansion of the area of the q2q2 model validity for light ...scalars on ever new processes seems extremely interesting and important. We analyze the BESIII data on the decay J/ψ → γπ0π0 and show that the results of this high-statistics experiment can be interpreted in favor of the four-quark nature of light scalar mesons f0(980) and f0 (500).
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 activity concentration of
40
K in soils of Rostov agglomeration was studied. Natural and anthropogenically modified soils of Rostov agglomeration were studied: Haplic Chernozems, Haplic ...Chernozems (Technic), Urbic Technosols. Activity concentration
40
K in soils was measured by gamma-spectrometric method of radionuclide analysis. The total mass fraction of K
2
O was determined by X-ray fluorescence method on a Spectroscan MAKS-GV instrument. Knowing the total mass fraction of K
2
O, we calculated its potential radioactivity based on the fact that one gram of natural potassium has an activity concentration of 28.5 Bq. Comparison of the two methods allows estimating the involvement of
40
K in biogenic cycles. No significant differences between the actual and calculated activity concentration of
40
K in the soil-forming rock were revealed, while in horizons A and B the calculated activity is significantly higher. At the same time, there are no reliable differences between native and their buried analogs. The direct influence of the granulometric composition on the activity concentration of
40
K was not established, but in the urban horizons with lightened granulometric composition the average activity of
40
K is the lowest by reliably significant values when comparing this index with native, buried horizons and the group of heavy urban horizons. This implies that
40
K is more actively involved in biogenic cycles than its stable isotopes. The burial under urban deposits is accompanied by a weak change in the activity concentration of
40
K in the profile, while the difference between genetic horizons is leveled out.
Phosphorylated derivatives of polysaccharides (PSs) such as water-soluble starch, carboxymethylcellulose, apple pectin, poly(galacturonic acid), alginic acid, poly(mannuronic acid), poly(guluronic ...acid), chitosan, and arabinogalactan were prepared under mild conditions by solid-phase reactions with P
2
O
5
. The phosphorylation reactions featured formation of various types of fragments from mono- and disubstituted monophosphates to disubstituted polyphosphates in the PS phosphates.
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 results of a numerical study of heating and destruction of a biological tissue under the action of a series of focused ultrasound pulses generated by a multielement array (tumor treatment ...programs) are presented. Irradiation programs are considered that differ in the locations of focal points within a tissue (the Archimedean and “square” spirals), the number of pulses in the series, and the time delay between pulses. A significant influence of the parameters of the pulse series and perfusion process on the size of the thermal lesion area in a tissue was established in a considered range of moderate intensities of radiation. It was shown that the heat propagation process in the tissue turns with time to a quasi-spherical pattern and is weakly dependent on the irradiation program type. This characteristic of the process is discussed in terms of its possible use to optimize protocols of medical procedures utilizing focused ultrasound.
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.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.
The process e+e−→K+K− has been studied using 1.7×106 events from a data sample corresponding to an integrated luminosity of 5.7 pb−1 collected with the CMD-3 detector in the center-of-mass energy ...range 1010–1060 MeV. The cross section is measured with about 2% systematic uncertainty and is used to calculate the contribution to the anomalous magnetic moment of the muon aμK+K−=(19.33±0.40)×10−10, and to obtain the ϕ(1020) meson parameters. We consider the relationship between the e+e−→K+K− and e+e−→KS0KL0 cross sections and compare it to the theoretical prediction.
The process e+e−→K+K−η has been studied in the center-of-mass energy range from 1.59 to 2.007 GeV using the data sample of 59.5 pb−1, collected with the CMD-3 detector at the VEPP-2000 e+e− collider ...in 2011, 2012 and 2017. The K+K−η final state is found to be dominated by the contribution of the ϕ(1020)η intermediate state. The cross section of the process e+e−→ϕ(1020)η has been measured with a systematic uncertainty of 5.1% on the base of 3009 ± 67 selected events. The obtained cross section has been used to calculate the contribution to the anomalous magnetic moment of the muon: aμϕη(E<1.8GeV)=(0.321±0.015stat±0.016syst)×10−10, aμϕη(E<2.0GeV)=(0.440±0.015stat±0.022syst)×10−10. From the cross section approximation the ϕ(1680) meson parameters have been determined with better statistical precision, than in previous studies.
The main principles of using wires with tungsten nanopowder for arc cladding are considered. Special features of production and application of tungsten-modified wires are analyzed. The microstructure ...of the high-strength layer obtained by cladding wires with different tungsten nanopowder contents is investigated. Microhardness of clad specimens is determined.
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