First analysis of anisotropic flow with Lee--Yang zeroes

We report on the first analysis of directed and elliptic flow with the new method of Lee--Yang zeroes. Experimental data are presented for Ru+Ru reactions at 1.69 AGeV measured with the FOPI detector at SIS/GSI. The results obtained with several methods, based on the event-plane reconstruction, on Lee--Yang zeroes, and on multi-particle cumulants (up to 5th order) applied for the first time at SIS energies, are compared. They show conclusive evidence that azimuthal correlations between nucleons and composite particles at this energy are largely dominated by anisotropic flow.Comment: 5 pages, 3 figures, submitted to Phys. Rev. C Rapid Co

Direct comparison of phase-space distributions of K- and K+ mesons in heavy-ion collisions at SIS energies - evidence for in-medium modifications of kaons ?

The ratio of K- to K+ meson yields has been measured in the systems RuRu at 1.69 A GeV, Ru+Zr at 1.69 A GeV, and Ni+Ni at 1.93 A GeV incident beam kinetic energy. The yield ratio is observed to vary across the measured phase space. Relativistic transport-model calculations indicate that the data are best understood if in-medium modifications of the kaons are taken into account.Comment: 14 pages including 3 figure

Isospin-tracing: A probe of non-equilibrium in central heavy-ion collisions

Four different combinations of $^{96}_{44}$Ru and $^{96}_{40}$Zr nuclei, both as projectile and target, were investigated at the same bombarding energy of 400$A$ MeV using a $4 \pi$ detector. The degree of isospin mixing between projectile and target nucleons is mapped across a large portion of the phase space using two different isospin-tracer observables, the number of measured protons and the ${\rm t}/^{3}{\rm He}$ yield ratio. The experimental results show that the global equilibrium is not reached even in the most central collisions. Quantitative measures of stopping and mixing are extracted from the data. They are found to exhibit a quite strong sensitivity to the in-medium (n,n) cross section used in microscopic transport calculations.Comment: 4 pages RevTeX, 3 figures (ps files), submitted to Phys. Rev. Let

Sideward flow of K+ mesons in Ru+Ru and Ni+Ni reactions near threshold

Experimental data on K+ meson and proton sideward flow measured with the FOPI detector at SIS/GSI in the reactions Ru+Ru at 1.69 AGeV and Ni+Ni at 1.93 AGeV are presented. The K+ sideward flow is found to be anti-correlated (correlated) with the one of protons at low (high) transverse momenta. When compared to the predictions of a transport model, the data favour the existence of an in-medium repulsive K+ nucleon potential.Comment: 16 pages Revtex, 3 ps-figures, submitted to Phys. Lett.

Identification of baryon resonances in central heavy-ion collisions at energies between 1 and 2 AGeV

The mass distributions of baryon resonances populated in near-central collisions of Au on Au and Ni on Ni are deduced by defolding the $p_t$ spectra of charged pions by a method which does not depend on a specific resonance shape. In addition the mass distributions of resonances are obtained from the invariant masses of $(p, \pi^{\pm})$ pairs. With both methods the deduced mass distributions are shifted by an average value of -60 MeV/c$^2$ relative to the mass distribution of the free $\Delta(1232)$ resonance, the distributions descent almost exponentially towards mass values of 2000 MeV/c^2. The observed differences between $(p, \pi^-)$ and $(p, \pi^+)$ pairs indicate a contribution of isospin $I = 1/2$ resonances. The attempt to consistently describe the deduced mass distributions and the reconstructed kinetic energy spectra of the resonances leads to new insights about the freeze out conditions, i.e. to rather low temperatures and large expansion velocities.Comment: 30 pages, 13 figures, Latex using documentstyle[12pt,a4,epsfig], to appear in Eur. Phys. J.

Flow angle from intermediate mass fragment measurements

Directed sideward flow of light charged particles and intermediate mass fragments was measured in different symmetric reactions at bombarding energies from 90 to 800 AMeV. The flow parameter is found to increase with the charge of the detected fragment up to Z = 3-4 and then turns into saturation for heavier fragments. Guided by simple simulations of an anisotropic expanding thermal source, we show that the value at saturation can provide a good estimate of the flow angle, $\Theta_{flow}$, in the participant region. It is found that $\Theta_{flow}$ depends strongly on the impact parameter. The excitation function of $\Theta_{flow}$ reveals striking deviations from the ideal hydrodynamical scaling. The data exhibit a steep rise of \Theta_{\flow} to a maximum at around 250-400 AMeV, followed by a moderate decrease as the bombarding energy increases further.Comment: 28 pages Revtex, 6 figures (ps files), to appear in Nucl.Phys.

K^+ production in the reaction 58Ni+58Ni^{58}Ni+^{58}Ni at incident energies from 1 to 2 AGeV

Semi-inclusive triple differential multiplicity distributions of positively charged kaons have been measured over a wide range in rapidity and transverse mass for central collisions of $^{58}$Ni with $^{58}$Ni nuclei. The transverse mass ($m_t$) spectra have been studied as a function of rapidity at a beam energy 1.93 AGeV. The $m_t$ distributions of K^+ mesons are well described by a single Boltzmann-type function. The spectral slopes are similar to that of the protons indicating that rescattering plays a significant role in the propagation of the kaon. Multiplicity densities have been obtained as a function of rapidity by extrapolating the Boltzmann-type fits to the measured distributions over the remaining phase space. The total K^+ meson yield has been determined at beam energies of 1.06, 1.45, and 1.93 AGeV, and is presented in comparison to existing data. The low total yield indicates that the K^+ meson can not be explained within a hadro-chemical equilibrium scenario, therefore indicating that the yield does remain sensitive to effects related to its production processes such as the equation of state of nuclear matter and/or modifications to the K^+ dispersion relation.Comment: 24 pages Latex (elsart) 7 PS figures to be submitted to Nucl. Phys

Разработка методического подхода к поддержке и анализу исполнения стандартов лечебно-диагностических процессов многопрофильного стационара

Standardization is one of the most important tools for ensuring the quality of medical care. The paper presents analysis results of a number of existing federal and regional standards that regulate the processes of providing medical care, which confirm the need and expediency of developing internal standards for diagnostic and treatment processes (DTP) in a medical institution. The authors also formulate requirements for their minimum content. The importance of the effective implementation of the developed internal DTP standards necessitates the development of a methodological approach to standard execution support and analysis.The approach presented in the article is methodically based on the use of modified operogrammes, which allow taking into account the DTP specifics and resource equipment of a particular medical institution. The authors propose key areas for standard execution support and possible forms of implementation in information systems, as well as basic directions for standard execution analysis with integral indicators for assessment of those standards.Approbation of the developed methodological approach was carried out on the example of the N.V. Sklifosovsky Research Institute for Emergency Medicine in terms of DTP standard execution support and analysis in relation to ordering laboratory, instrumental tests and consultations at various stages of the patient treatment process. The results of the approbation confirmed that the introduction of the methodological approach increases the effectiveness of the implementation of the developed DTP standards in the activities of a medical institution, and also ensures the achievement of a number of important systemic management effects.Одним из важнейших инструментов обеспечения качества медицинской помощи является стандартизация. В работе представлены результаты анализа ряда действующих федеральных и региональных стандартов, регламентирующих процессы оказания медицинской помощи, которые подтверждают необходимость и целесообразность разработки внутренних стандартов лечебнодиагностических процессов (ЛДП) медицинского учреждения, авторами также сформулированы требования к их минимальному содержанию. Важность эффективного внедрения разрабатываемых внутренних стандартов ЛДП обусловливает необходимость разработки методического подхода к поддержке и анализу исполнения стандартов. Представленный в статье подход методически основывается на применении модифицированных оперограмм, которые позволяют учесть специфику и ресурсное оснащение ЛДП конкретного медицинского учреждения. Авторами предложены ключевые направления поддержки исполнения стандартов и возможные формы реализации в информационных системах, а также базовые направления анализа исполнения стандартов с интегральными показателями их оценки. Апробация разработанного методического подхода проведена на примере ЛДП ГБУЗ «НИИ СП им. Н.В. Склифосовского ДЗМ» в части поддержки и анализа исполнения стандартов ЛДП по назначениям лабораторных, инструментальных исследований и консультаций на различных этапах процессов лечения пациентов. Результаты апробации подтвердили, что применение данного методического подхода повышает эффективность внедрения разработанных стандартов ЛДП в деятельность медицинского учреждения, а также обеспечивает достижение ряда важных системных управленческих эффектов

Mass and charge identification of fragments detected with the Chimera Silicon-CsI(Tl) telescopes

Mass and charge identification of charged products detected with Silicon-CsI(Tl) telescopes of the Chimera apparatus is presented. An identification function, based on the Bethe-Bloch formula, is used to fit empirical correlation between Delta E and E ADC readings, in order to determine, event by event, the atomic and mass numbers of the detected charged reaction products prior to energy calibration.Comment: 24 pages, 7 .jpg figures, submitted to Nucl.Instr.