The gluon content of the η\eta and η′\eta^{\prime} mesons and the ηγ\eta\gamma, η′γ\eta^{\prime}\gamma electromagnetic transition form factors

We compute power-suppressed corrections to the \eta\gamma and \eta^{\prime}\gamma transition form factors Q^2F_{\eta(\eta^{\prime})\gamma}(Q^2) arising from the end point regions x \to 0,1 by employing the infrared-renormalon approach. The contribution to the form factors from the quark and gluon content of the \eta,\eta^{\prime} mesons is taken into account using for the \eta-\eta^{\prime} mixing the SU_f(3) singlet \eta_1 and octet \eta_8 basis. The theoretical predictions obtained this way are compared with the corresponding CLEO data and restrictions on the input parameters (Gegenbauer coefficients) B_2^q(\eta_1), B_2^g(\eta_1), and B_2^q(\eta_8) in the distribution amplitudes for the \eta_1,\eta_8 states with one nonasymptotic term are deduced. Comparison is made with the results from QCD perturbation theory.Comment: 25 pages, RevTeX4 used. 9 figures as EPS files. Text significantly changed to include variation of theoretical parameters. Figures modified. Corrected typo in equation (34) and trivial mistake in $\beta_1$-coefficient. References added. Conclusions unchange

Пассажирские перевозки и оптимизация городской маршрутной сети

[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT The authors propose measures to optimize the urban route network of passenger transport. In accordance with the tasks of optimization, a program and methodology for the survey of passenger flows, a more rational scheme for the route network, a transport macro model for the city, a passenger navigation system for the GLONASS or GLONASS/ GPS monitoring system, security monitoring systems and mobile objects management were developed. Keywords: public transport, urban route network, passenger transportation, optimization, monitoring, GLONASS, macro model, passenger flows.Текст аннотации на англ. языке и полный текст статьи на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).Авторы предлагают меры по оптимизации городской маршрутной сети пассажирского транспорта. В соответствии с задачами оптимизации разработаны программа и методика обследования пассажиропотоков, более рациональная схема маршрутной сети, транспортная макромодель города, предусмотрено внедрение в сфере пассажирских перевозок навигационной системы мониторинга ГЛОНАСС или ГЛОНАСС/GPS, системы мониторинга безопасности и управления подвижными объектами

Clinical Features and the NT-proBNP Marker in Patients with Chronic Heart Failure in the Setting of Atrial Fibrillation and Chronic Obstructive Pulmonary Disease

Aim: To determine the clinical features and analyse the concentration of the heart failure (HF) marker in patients with atrial fi brillation (AF) and chronic obstructive pulmonary disease (COPD).Materials and methods: 120 patients were divided into the following groups: 1) experimental group including patients with chronic heart failure (CHF), AF and COPD (n = 29); 2) comparison group 1 including patients with COPD, but without cardiovascular diseases (CVD) (n = 28); 3) comparison group 2 consisting of patients with CHF and COPD, but without AF (n = 30); 4) comparison group 3 comprising patients with CHF and AF, but without COPD (n = 33). Clinical symptoms and tolerance to physical load were assessed for all patients with CHF using the clinical condition scale (CCS) and the 6 Minute Walk Test (6MWT), respectively. The severity of dyspnoea was assessed (mMRC scale) in the groups of patients with COPD. The concentration of NT-proBNP was analysed using a Biomedica NT-proBNP reagent pack (SK-1204).Results: A comparative analysis of the CHF clinical manifestations (according to CCS) in the study groups showed higher median values in the group of patients with CHF, AF and COPD, as compared to the same indicator in patients with CHF and AF, but without COPD (p < 0.001). An intergroup analysis of the dyspnoea symptom using the mMRC scale showed the lowest degree of dyspnoea in the group with COPD and without CVD, which signifi cantly differed from the same indicator in patients with CHF and COPD, but without AF (p = 0.015). The 6MWT results did not reveal signifi cant differences between the groups (p = 0.017). In assessing the level of the HF marker, higher concentrations of NT-proBNP were found in the group of patients with CHF, AF and COPD, which exceeded its concentration in patients with CHF and COPD, but without AF (p = 0.0003), as well as in patients with CHF and AF, but without COPD (p = 0.01).Conclusion: 1. Due to the presence of chronic bronchial obstructive syndrome, higher severity of clinical HF symptoms was established in patients with CHF, AF and COPD – as compared to the group including patients with CHF and AF, but without COPD. 2. A statistically signifi cant higher level of NT-proBNP was determined in patients with CHF, AF and COPD, which is associated with the presence of hemodynamic load on both ventricles of the heart under the mutual infl uence of AF and chronic bronchial obstruction on the hemodynamics of the pulmonary circulation

First observation of a narrow charm-strange meson DsJ(2632) -> Ds eta and D0 K+

We report the first observation of a charm-strange meson DsJ(2632) at a mass of 2632.6+/-1.6 MeV/c^2 in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, Ds eta and D0 K+. In the Ds eta decay mode we observe an excess of 49.3 events with a significance of 7.2sigma at a mass of 2635.9+/-2.9 MeV/c^2. There is a corresponding peak of 14 events with a significance of 5.3sigma at 2631.5+/-1.9 MeV/c^2 in the decay mode D0 K+. The decay width of this state is <17 MeV/c^2 at 90% confidence level. The relative branching ratio Gamma(D0K+)/Gamma(Dseta) is 0.16+/-0.06. The mechanism which keeps this state narrow is unclear. Its decay pattern is also unusual, being dominated by the Ds eta decay mode.Comment: 5 pages, 3 included eps figures. v2 as accepted for publication by PR

First Observation of the Doubly Charmed Baryon Xi_cc^+

We observe a signal for the doubly charmed baryon Xi_cc^+ in the charged decay mode Xi_cc^+ --> Lambda_c^+ K- pi+ in data from SELEX, the charm hadro-production experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1 +/- 0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is (3519 +/- 1) MeV/c^2. The Gaussian mass width of this state is 3MeV/c^2, consistent with resolution; its lifetime is less than 33fsec at 90% confidence.Comment: 5 pages, 3 figures, accepted for publication in Physical Review Letter

First Measurement of pi e -> pi e gamma Pion Virtual Compton Scattering

Pion Virtual Compton Scattering (VCS) via the reaction pi e --> pi e gamma was observed in the Fermilab E781 SELEX experiment. SELEX used a 600 GeV/c pi- beam incident on target atomic electrons, detecting the incident pi- and the final state pi-, electron and gamma. Theoretical predictions based on chiral perturbation theory are incorporated into a Monte Carlo simulation of the experiment and are compared to the data. The number of reconstructed events (9) and their distribution with respect to the kinematic variables (for the kinematic region studied) are in reasonable accord with the predictions. The corresponding pi- VCS experimental cross section is sigma=38.8+-13 nb, in agreement with the theoretical expectation sigma=34.7 nb.Comment: 10 pages, 12 figures, 4 tables, 25 references, SELEX home page is http://fn781a.fnal.gov/, revised July 21, 2002 in response to journal referee Comment

Observation of the Cabibbo-suppressed decay Xi_c+ -> p K- pi+

We report the first observation of the Cabibbo-suppressed charm baryon decay Xi_c+ -> p K- pi+. We observe 150 +- 22 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Sigma- beam. The branching fractions of the decay relative to the Cabibbo-favored Xi_c+ -> Sigma+ K- pi+ and Xi_c+ -> X- pi+ pi+ are measured to be B(Xi_c+ -> p K- pi+)/B(Xi_c+ -> Sigma+ K- pi+) = 0.22 +- 0.06 +- 0.03 and B(Xi_c+ -> p K- pi+)/B(Xi_c+ -> X- pi+ pi+) = 0.20 +- 0.04 +- 0.02, respectively.Comment: 5 pages, RevTeX, 3 figures (postscript), Submitted to Phys. Rev. Let

Measurement of the Ds lifetime

We report precise measurement of the Ds meson lifetime. The data were taken by the SELEX experiment (E781) spectrometer using 600 GeV/c Sigma-, pi- and p beams. The measurement has been done using 918 reconstructed Ds. The lifetime of the Ds is measured to be 472.5 +- 17.2 +- 6.6 fs, using K*(892)0K+- and phi pi+- decay modes. The lifetime ratio of Ds to D0 is 1.145+-0.049.Comment: 5 pages, 2 figures submitted to Phys. Lett.