7,336 research outputs found
Study of psi' and chi_c decays as feed-down sources of J/psi hadro-production
The interpretation of the J/psi suppression patterns observed in nuclear
collisions, at CERN and RHIC, as a signature of the formation of a deconfined
phase of QCD matter, requires knowing which fractions of the measured J/psi
yields, in pp collisions, are due to decays of heavier charmonium states. From
a detailed analysis of the available mid-rapidity charmonium hadro-production
cross sections, or their ratios, we determine that the J/psi feed-down
contributions from psi' and chi_c decays are, respectively, (8.1 +/- 0.3) % and
(25 +/- 5) %. These proton-proton values are derived from global averages of
the proton-nucleus measurements, assuming that the charmonium states are
exponentially absorbed with the length of matter they traverse in the nuclear
targets.Comment: 12 pages, 4 figures, 3 table
From âcreative citiesâ to âurban creativityâ? Space, creativity and governance in the contemporary city
DINĂMIA, Dezembro de 2009This paper derives from a broader research program studying the forms of governance associated with creative dynamics in cities (the âCreatcityâ project) and draws on the first empirical results generated by the
study following analysis of a set of exploratory interviews involving actors central to thinking and acting on
the contemporary city (political decision makers, official structures and civil society) in the three
metropolitan areas selected for the project: Lisbon (Portugal), SĂŁo Paulo (Brazil) and Barcelona (Spain).
Analysis of the responses sought to identify the different perspectives on the concepts of urban creativity and
creative city and the relationship between creativity, vitality and competitivity within urban contexts while seeking to understand interviewee perspectives on the structural conditions necessary for the development of
creativity in the city in terms of spatial/geographic configurations and the associated cultural ambiances and
economic activities. In parallel, we aim to debate the means of fostering and supporting creativity in urban environments and discuss just which strategic policies and governance processes best achieve this.FC
Heavy-ion Physics at a Fixed-Target Experiment Using the LHC Proton and Lead Beams (AFTER@LHC): Feasibility Studies for Quarkonium and Drell-Yan Production
We outline the case for heavy-ion-physics studies using the multi-TeV lead
LHC beams in the fixed-target mode. After a brief contextual reminder, we
detail the possible contributions of AFTER@LHC to heavy-ion physics with a
specific emphasis on quarkonia. We then present performance simulations for a
selection of observables. These show that , and
production in heavy-ion collisions can be studied in new energy and
rapidity domains with the LHCb and ALICE detectors. We also discuss the
relevance to analyse the Drell-Yan pair production in asymmetric
nucleus-nucleus collisions to study the factorisation of the nuclear
modification of partonic densities and of further quarkonia to restore their
status of golden probes of the quark-gluon plasma formation.Comment: 18 pages, 7 figure
Arl13b interferes with α-tubulin acetylation
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First record of the Hauxwell's Thrush, Turdus hauxwelli Lawrence, 1869 (Aves: Turdidae) from Mato Grosso do Sul, Brazil, and geographic range extension
We report the first record of the Hauxwellâs Thrush, Turdus hauxwelli Lawrence, 1869 (Aves: Turdidae) in the state of Mato Grosso do Sul, Brazil. During an ornithological inventory conducted in Serra de MaracajĂș, municipality of Corguinho, we mist-netted and collected an individual of the species. The specimen was prepared as study skin and is held in the ornithological collection of the Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro. This record is located 472 km south of the closest visual/song record and 616 km southeast of the closest museum specimen, being the southernmost occurrence of this thrush
Simulation of Offshore Wind System with Three-Level Converters: HVDC Power Transmission in Cloud Scope
This paper is on a simulation for offshore wind systems in deep water
under cloud scope. The system is equipped with a permanent magnet synchronous
generator and a full-power three-level converter, converting the electric energy at
variable frequency in one at constant frequency. The control strategies for the
three-level are based on proportional integral controllers. The electric energy is injected
through a HVDC transmission submarine cable into the grid. The drive train
is modeled by a three-mass model taking into account the resistant stiffness torque,
structure and tower in the deep water due to the moving surface elevation. Conclusions
are taken on the influence of the moving surface on the energy conversion
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