Search for rare or forbidden decays of the D0 meson

We present a search for nine lepton-number-violating and three lepton-flavor-violating neutral charm decays of the type D0→h'−h−ℓ'+ℓ+ and D0→h'−h+ℓ'±ℓ∓, where h and h′ represent a K or π meson and ℓ and ℓ′ an electron or muon. The analysis is based on 468 fb−1 of e+e− annihilation data collected at or close to the Υ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the twelve modes, and we establish 90% confidence level upper limits on the branching fractions in the range (1.0–30.6)×10−7. The limits are between 1 and 3 orders of magnitude more stringent than previous measurements.publishedVersio

Measurements of the absolute branching fractions of B± →k±Xc c

A study of the two-body decays B±→Xc¯cK±, where Xc¯c refers to one charmonium state, is reported by the BABAR Collaboration using a data sample of 424 fb−1. The absolute determination of branching fractions for these decays are significantly improved compared to previous BABAR measurements. Evidence is found for the decay B+→X(3872)K+ at the 3σ level. The absolute branching fraction B[B+→X(3872)K+]=[2.1±0.6(stat)±0.3(syst)]×10−4 is measured for the first time. It follows that B[X(3872)→J/ψπ+π−]=(4.1±1.3)%, supporting the hypothesis of a molecular component for this resonance.publishedVersio

Light meson spectroscopy from Dalitz plot analyses of ηc decays to η0 K+K− , η0 π + π − , and ηπ + π − produced in two-photon interactions

We study the processes γγ→ηc→η′K+K−, η′π+π−, and ηπ+π− using a data sample of 519  fb−1 recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy e+e− collider at center-of-mass energies at and near the Υ(nS) (n=2, 3, 4) resonances. This is the first observation of the decay ηc→η′K+K− and we measure the branching fraction Γ(ηc→η′K+K−)/(Γ(ηc→η′π+π−)=0.644±0.039stat±0.032sys. Significant interference is observed between γγ→ηc→ηπ+π− and the nonresonant two-photon process γγ→ηπ+π−. A Dalitz plot analysis is performed of ηc decays to η′K+K−, η′π+π−, and ηπ+π−. Combined with our previous analysis of ηc→K¯Kπ, we measure the K∗0(1430) parameters and the ratio between its η′K and πK couplings. The decay ηc→η′π+π− is dominated by the f0(2100) resonance, also observed in J/ψ radiative decays. A new a0(1700)→ηπ resonance is observed in the ηc→ηπ+π− channel. We also compare ηc decays to η and η′ final states in association with scalar mesons as they relate to the identification of the scalar glueball.publishedVersio

Recent Results on Two-Photon Physics at BaBar

The authors present measurements of the {gamma}{gamma}* {yields} {pi}{sup 0} transition form factor for the momentum transfer range Q{sup 2} = 4-40 GeV{sup 2} and the {gamma}{gamma}* {yields} {eta}{sub c} transition form factor for the range Q{sup 2} = 2-50 GeV{sup 2}. The results of the measurement of the {eta}{sub c} mass, total and two-photon widths are also presented

Assessment of radioactivity of environmental components in the Kostomuksha State Nature Reserve

The radiological state of the land and water areas constantly attracts public interest. Specially protected natural reservations deserve special attention when it comes to studying radiological conditions. This study presents findings of radioecological investigations conducted in the Kostomuksha State Nature Reserve in 2012 – 2015. The Kostomuksha Mining Company, which is developing the Kostomuksha iron ore deposit was identified as a potentially hazardous facility that might affect the radioecological situation in the naturel reserve, since production of iron ores at the deposit involves extraction to the ground surface of acid rocks characterised by a naturally high content of radioactive elements (granitic gneiss). Furthermore, several sources of radioactive radon gas have been identified within the reserve boundaries. The study included investigation of natural and anthropogenic radioactivity in the environmental components of the nature reserve and adjacent territories, including soil, plants, bottom sediments, ambient air and natural waters. It was found that development of the Kostomuksha iron ore deposit and operations of the mining and processing plant do not exert any considerable impact on the radiological situation in the nature reserve. Data obtained during the study indicate that the overall radiological situation in the reserve is acceptable and meets the relevant radiation safety standards. High levels of radiocesium were found in the moss and bottom sediments of the nature reserve, which requires additional research to determine a wider pattern of distribution of anthropogenic radioactivity across the adjacent territories and to study the processes of buildup and migration of radionuclides in aquatic organisms of Kamennoye Lake

Detecting Defects in Composite Polymers by Using 3D Scanning Laser Doppler Vibrometry

The technique of 3D scanning laser Doppler vibrometry has recently appeared as a promising tool of nondestructive evaluation of discontinuity-like defects in composite polymers. The use of the phenomenon of local defect resonance (LDR) allows intensifying vibrations in defect zones, which can reliably be detected by means of laser vibrometry. The resonance acoustic stimulation of structural defects in materials causes compression/tension deformations, which are essentially lower than the material tensile strength, thus proving a nondestructive character of the LDR technique. In this study, the propagation of elastic waves in composites and their interaction with structural inhomogeneities were analyzed by performing 3D scanning of vibrations in Fast Fourier Transform mode. At each scanning point, the in-plane (x, y) and out of plane (z) vibration components were analyzed. The acoustic stimulation was fulfilled by generating a frequency-modulated harmonic signal in the range from 50 Hz to 100 kHz. In the case of a reference plate with a flat bottom hole, the resonance frequencies for all (x, y, and z) components were identical. In the case of impact damage in a carbon fiber reinforced plastic sample, the predominant contribution into total vibrations was provided by compression/tension deformations (x, y vibration component) to compare with vibrations by the z coordinate. In general, inspection results were enhanced by analyzing total vibration patterns obtained by averaging results at some resonance frequencies

Sputum Microbiota in Coal Workers Diagnosed with Pneumoconiosis as Revealed by 16S rRNA Gene Sequencing

Coal worker’s pneumoconiosis (CWP) is an occupationally induced progressive fibrotic lung disease. This irreversible but preventable disease currently affects millions across the world, mainly in countries with developed coal mining industries. Here, we report a pilot study that explores the sputum microbiome as a potential non-invasive bacterial biomarker of CWP status. Sputum samples were collected from 35 former and active coal miners diagnosed with CWP and 35 healthy controls. Sequencing of bacterial 16S rRNA genes was used to study the taxonomic composition of the respiratory microbiome. There was no difference in alpha diversity between CWP and controls. The structure of bacterial communities in sputum samples (β diversity) differed significantly between cases and controls (pseudo-F = 3.61; p = 0.004). A significant increase in the abundance of Streptococcus (25.12 ± 11.37 vs. 16.85 ± 11.35%; p = 0.0003) was detected in samples from CWP subjects as compared to controls. The increased representation of Streptococcus in sputum from CWP patients was associated only with the presence of occupational pulmonary fibrosis, but did not depend on age, and did not differ between former and current miners. The study shows, for the first time, that the sputum microbiota of CWP subjects differs from that of controls. The results of our present exploratory study warrant further investigations on a larger cohort

Modeling of Technological Schemes for Production of Motor Spirits

Определены возможные и наиболее целесообразные направления развития технологической схемы нефтеперерабатывающего предприятия, обеспечивающие выпуск моторных топлив в соответствии с мировыми экологическими и эксплуатационными требованиями. Выход светлых нефтепродуктов при реализации схемы №1 в целом по заводу составит 86,8 %, а для схемы №2 - 87,2 % при глубине переработки нефти ~96 %.Possible and most expedient directions of technological scheme of the oil refining factory providing output of motor fuels in conformity with world environmental and operational requirements.are determined. The yield of refined oils at implementation of the schema №1 as a whole on plant will compound 86,8 %, and for the schema №2 - 87,2 % at depth of petroleum refining of ~96 %