62 research outputs found
Dynamics of Cryogenic Jets: Non-Rayleigh Breakup and Onset of Nonaxisymmetric Motions
We report development of generators for periodic, satellite-free fluxes of
mono-disperse drops with diameters down to 10 mikrometers from cryogenic
liquids like H_2, N_2, Ar and Xe (and, as reference fluid, water). While the
breakup of water jets can well be described by Rayleigh's linear theory, we
find jet regimes for H_2 and N_2 which reveal deviations from this behavior.
Thus, Rayleigh's theory is inappropriate for thin jets that exchange energy
and/or mass with the surrounding medium. Moreover, at high evaporation rates,
axial symmetry of the dynamics is lost. When the drops pass into vacuum, frozen
pellets form due to surface evaporation. The narrow width of the pellet flux
paves the way towards various industrial and scientific applications.Comment: 4 pages, 4 figures, 1 table; final version to appear in Phys.Rev.Lett
(minor changes with respect to v1
Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
This document is the Technical Design Report covering the two large
spectrometer magnets of the PANDA detector set-up. It shows the conceptual
design of the magnets and their anticipated performance. It precedes the tender
and procurement of the magnets and, hence, is subject to possible modifications
arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti
Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski,
Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy),
Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
Simulation results for future measurements of electromagnetic proton form
factors at \PANDA (FAIR) within the PandaRoot software framework are reported.
The statistical precision with which the proton form factors can be determined
is estimated. The signal channel is studied on the basis
of two different but consistent procedures. The suppression of the main
background channel, , is studied.
Furthermore, the background versus signal efficiency, statistical and
systematical uncertainties on the extracted proton form factors are evaluated
using two different procedures. The results are consistent with those of a
previous simulation study using an older, simplified framework. However, a
slightly better precision is achieved in the PandaRoot study in a large range
of momentum transfer, assuming the nominal beam conditions and detector
performance
At the intersection of globalization and "civilizational originality' : cultural production in Putin's Russia
This special issue originates from a transnational collaboration of scholars in philology, comparative literature, social theory, sociology, anthropology, ethnography, and media studies. The collection strives to advance a research agenda built on the nexus of three intellectual and academic domains: post-Soviet Russian cultural studies', the research paradigm put forward by Cultural Studies, as well as empirical methods developed in sociology. The collection illustrates the importance of expanding the experience of Cultural Studies beyond its established spheres of national investigation, while it also speaks to the necessity to re-evaluate the hegemony of the English-language academic and cultural production on the global scale. The collection offers insights into the gamut of cultural practices and institutional environments in which Russian cultural production happens today. It shows how cultural industries and institutions in Russia are integrated into the global marketplace and transnational communities, while they also draw on and contribute to local lives and experiences by trying to create an autonomous space for symbolic production at personal and collective levels. Through diverse topics, the issue sheds light on the agency, i.e. practitioners and participants, creators and consumers, of Russian cultural production and the neoliberal practices implemented on creative work and cultural administration in Russia today. The Introduction outlines the development of academic studies on Russian cultural practices since 1991; describes main political developments shaping the cultural field in Putin's Russia; and, finally, identifies the Cultural Studies debates the editors of the collection find most productive for investigations of Russia, i.e. the instrumentalization of culture and culture as resource. Relocated in an analysis of a post-socialist society, these conceptualisations seem increasingly problematic in a situation where local and federal policies governing cultural and creative work focus simultaneously on marketization and on nationalism as the main tools of legitimizing the federal government.Peer reviewe
Technical Design Report for the: PANDA Micro Vertex Detector
This document illustrates the technical layout and the expected performance
of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect
charged particles as close as possible to the interaction zone. Design criteria
and the optimisation process as well as the technical solutions chosen are
discussed and the results of this process are subjected to extensive Monte
Carlo physics studies. The route towards realisation of the detector is
outlined.Comment: 189 pages, 225 figures, 41 table
Physics Performance Report for PANDA: Strong Interaction Studies with Antiprotons
To study fundamental questions of hadron and nuclear physics in interactions
of antiprotons with nucleons and nuclei, the universal PANDA detector will be
built. Gluonic excitations, the physics of strange and charm quarks and nucleon
structure studies will be performed with unprecedented accuracy thereby
allowing high-precision tests of the strong interaction. The proposed PANDA
detector is a state-of-the art internal target detector at the HESR at FAIR
allowing the detection and identification of neutral and charged particles
generated within the relevant angular and energy range. This report presents a
summary of the physics accessible at PANDA and what performance can be
expected.Comment: 216 page
Feasibility studies for the measurement of time-like proton electromagnetic form factors from p¯ p→ μ+μ- at P ¯ ANDA at FAIR
This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, | GE| and | GM| , using the p¯ p→ μ+μ- reaction at P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is p¯ p→ π+π-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented
Study of doubly strange systems using stored antiprotons
Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P‾ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ−-atoms will be feasible and even the production of Ω−-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ω−-nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions
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