The results of an analysis of data from the SERP-Е-184 experiment devoted to studying mechanisms of the production of charmed particles in proton–nucleus interactions at 70 GeV and their decays are ...presented. The data in question were obtained upon irradiating the SVD-2 active target consisting of carbon, silicon, and lead plates with a beam of 70-GeV protons. A detailed simulation on the basis of the FRITIOF7.02 and GEANT3.21 code packages made it possible to optimize event-selection criteria and to calculate the detection efficiency for Λ
c
+
baryons. After selecting a signal from the threebody decay of a Λ
c
+
baryon, the inclusive cross section for its production at near-threshold energies, its lifetime, and the parameter of the
A
dependence of the cross section were found. The Λ
c
+
-baryon yields are tabulated along with data from other experiments and theoretical predictions.
The system controlling movement of the γ detector in the spectrometer with a vertex detector (SVD) setup has been upgraded. The choice of circuitry components for designing the control interface, ...coordinate sensors, actuation mechanisms, and system of emergency shutdown is substantiated. The circuit designs allowing the reliability of the γ detector and its positioning accuracy to be increased are described. Commercially produced industrial controllers of asynchronous motors with frequency steering are used in the system. The software developed for controlling the γ detector movement is described. The system has been completely mounted and tested and now is ready for operation as a part of the SVD setup.
The stages of development and the current status of the versatile “Spectrometer with a Vertex Detector” setup designed for physics experiments at the U-70 accelerator of the Institute for High Energy ...Physics (Protvino) is described. The main detectors of the setup are the vertex detector based on silicon microstrip detectors, the wide-aperture magnetic spectrometer based on multiwire proportional chambers, and the lead-glass hodoscope γ detector. In the setup, there is a fast two-level trigger system for selecting required particle interactions. The key characteristics of the setup systems are presented, and the physical results obtained on it are briefly listed.
A soft photon calorimeter for the SVD-2 experiment Ardashev, E. N.; Britvich, G. I.; Vorobiev, A. P. ...
Instruments and experimental techniques (New York),
03/2015, Letnik:
58, Številka:
2
Journal Article
Recenzirano
The design of the soft photon calorimeter for the SVD-2 experiment is described. The aperture of the calorimeter is 210 × 210 mm. The first results of its testing in the course of data acquisition in ...the E-190 experiment at the U-70 accelerator of the Institute for High Energy Physics are presented.
The paper presents the results obtained for the malonic aldehyde—hydrogen peroxide and β-oxobutanal—hydrogen peroxide systems. The systems were studied by IR spectroscopy in xenon matrices. The ...potential energy surfaces and vibrational spectra of the molecules that could occur in these systems were calculated quantum-chemically. As distinct from similar systems with monoaldehydes and α-dioxo compounds, the first stage of the reactions that occurred in the systems under consideration involved the decomposition of hydrogen peroxide with the formation of atomic oxygen, whose secondary reactions determined the set of reaction products.
The radiative decay Λ(1520)→Λγ was measured directly in the study of the exclusive diffractive-like reaction p+N→Λ(1520)K++N, Λ(1520)→Λγ with the SPHINX spectrometer. The values of the branching and ...partial width of this radiative decay were obtained: BRΛ(1520)→Λγ=(1.02±0.21(stat)±0.15(syst))×10−2 and ΓΛ(1520)→Λγ=159±33(stat)±26(syst) keV.
The results of E-190 experiment (project Thermalization) with 50 GeV proton beam irradiation of SVD-2 setup are presented. MC simulation has shown the linear dependence of number of photons detected ...in electromagnetic calorimeter and the average number of neutral pions. Multiplicity distribution of neutral pion, N0, for total number of particles in the event, Ntot = Nch + N0, are obtained with corrections on the setup acceptance, triggering and efficiency of the event reconstruction. The scaled variance of neutral pion fluctuations, ω = D/ < N0 >, versus total multiplicity is measured. The fluctuations increase at Ntot > 18. According to quantum statistics models this behavior can indicate a pion condensate formation in the high pion multiplicity system. This effect has been observed for the first time.
Calcium phosphate bions (CPB) are biomimetic mineralo-organic nanoparticles which represent a physiological mechanism regulating the function, transport and disposal of calcium and phosphorus in the ...human body. We hypothesised that CPB may be pathogenic entities and even a cause of cardiovascular calcification. Here we revealed that CPB isolated from calcified atherosclerotic plaques and artificially synthesised CPB are morphologically and chemically indistinguishable entities. Their formation is accelerated along with the increase in calcium salts-phosphates/serum concentration ratio. Experiments in vitro and in vivo showed that pathogenic effects of CPB are defined by apoptosis-mediated endothelial toxicity but not by direct tissue calcification or functional changes in anti-calcification proteins. Since the factors underlying the formation of CPB and their pathogenic mechanism closely resemble those responsible for atherosclerosis development, further research in this direction may help us to uncover triggers of this disease.
In Europe, global data on guideline adherence, geographic variations, and determinants of clinical events in patients with chronic coronary syndrome (CCS) remain suboptimal. The European Society of ...Cardiology (ESC) EURObservational Research Programme (EORP) Chronic Ischemic Cardiovascular Disease Long-Term (CICD-LT) registry is a prospective European registry, and was designed to describe the profile, management, and outcomes of patients with CCS across the ESC countries.
We aimed to investigate clinical events at 1-year follow-up from the ESC EORP CICD-LT registry.One-year outcomes of 6655 patients from the 9174 recruited in this European registry were analysed. Overall, 168 patients (2.5%) died, mostly from cardiovascular (CV) causes (n = 97, 1.5%). Northern Europe had the lowest CV mortality rate, while southern Europe had the highest (0.5 vs. 2.0%, P = 0.04). Women had a higher rate of CV mortality compared with men (2.0 vs. 1.3%, P = 0.02). During follow-up, 1606 patients (27.1%) were hospitalized at least once, predominantly for CV indications (n = 1220, 20.6%). Among the population with measured low-density lipoprotein-cholesterol level at 1 year, 1434 patients (66.5%) were above the recommended target. Age, history of atrial fibrillation, previous stroke, liver disease, chronic obstructive pulmonary disease or asthma, increased serum creatinine, and impaired left ventricular function were associated with an increased risk of CV death or hospitalization.
In the CICD registry, the majority of patients with CCS have uncontrolled CV-risk factors. The 1-year mortality rate is low, but these patients are frequently hospitalized for CV causes. Early identification of comorbidities may represent an opportunity for enhanced care and better outcomes.
PDF
