72 research outputs found
Notulae to the Italian flora of algae, bryophytes, fungi and lichens: 2
In this contribution, new data concerning red algae, lichens and bryophytes of the Italian flora are presented. It includes new records and confirmations for the algal genus Grateloupia, the bryophyte genus Didymodon, and the lichen genera Buellia, Cladonia, Letharia, Pertusaria, and Pyrenula
Strange particle production in 158 and 40 GeV/ Pb-Pb and p-Be collisions
Results on strange particle production in Pb-Pb collisions at 158 and 40
GeV/ beam momentum from the NA57 experiment at CERN SPS are presented.
Particle yields and ratios are compared with those measured at RHIC.
Strangeness enhancements with respect to p-Be reactions at the same beam
momenta have been also measured: results about their dependence on centrality
and collision energy are reported and discussed.Comment: Contribution to the proceedings of the "Hot Quarks 2004" Conference,
July 18-24 2004, New Mexico, USA, submitted to Journal of Physics G 7 pages,
5 figure
Hadronic Structure in the Decay
We report on a study of the invariant mass spectrum of the hadronic system in
the decay tau- -> pi- pi0 nu_tau. This study was performed with data obtained
with the CLEO II detector operating at the CESR e+ e- collider. We present fits
to phenomenological models in which resonance parameters associated with the
rho(770) and rho(1450) mesons are determined. The pi- pi0 spectral function
inferred from the invariant mass spectrum is compared with data on e+ e- -> pi+
pi- as a test of the Conserved Vector Current theorem. We also discuss the
implications of our data with regard to estimates of the hadronic contribution
to the muon anomalous magnetic moment.Comment: 39 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Determination of the number of wounded nucleons in Pb+Pb collisions at 158 A GeV/c
The charged particle multiplicity distributions measured by two experiments, WA97 and NA57, in Pb+Pb collisions at 158 A GeV/c have been analyzed in the framework of the wounded nucleon model (WNM). We obtain a good description of the data within the centrality range of our samples. This allows us to make use of the measured multiplicities to estimate the number of wounded nucleons of the collision
Results on cascade production in lead-lead interactions from the NA57 experiment
The NA57 experiment has been designed to study the production of strange and multi-strange particles in Pb-Pb and p-Be collisions at the CERN SPS. The predecessor experiment WA97 has measured an enhanced abundance of strange particles in Pb-Pb collisions relative to p-A reactions at 160 GeV/c per nucleon beam momentum. NA57 has extended the WA97 measurements to investigate the evolution of the strangeness enhancement pattern as a function of the beam energy and over a wider centrality range. In this paper, we report results on cascade production for about the 60% most central collisions at 160 GeV/c per nucleon
Measurement of Branching Fractions for at Belle
We have measured the branching fractions for the exclusive decay modes using a data sample collected by the
Belle detector at the KEKB asymmetric-energy collider. The measured
branching fractions for , ,
and decay modes are
, ,
and ,
respectively, where the first error is statistical and the second error is
systematic. We do not observe statistically significant signals for the decay modes and set upper limits at the 90% confidence
level. We also study the helicity distribution for decay
mode and show that the longitudinal polarization component is dominant. {{\it
Keywords:} {-meson, Charmonium, Branching Fractions, Polarization}} {{\it
PACS:} 13.25.Hw, 11.30.Er}Comment: 21 pages, 5 figures, 3 tables. Submitted to PL
Global Diversity of Ascidiacea
The class Ascidiacea presents fundamental opportunities for research in the fields of development, evolution, ecology, natural products and more. This review provides a comprehensive overview of the current knowledge regarding the global biodiversity of the class Ascidiacea, focusing in their taxonomy, main regions of biodiversity, and distribution patterns. Based on analysis of the literature and the species registered in the online World Register of Marine Species, we assembled a list of 2815 described species. The highest number of species and families is found in the order Aplousobranchia. Didemnidae and Styelidae families have the highest number of species with more than 500 within each group. Sixty percent of described species are colonial. Species richness is highest in tropical regions, where colonial species predominate. In higher latitudes solitary species gradually contribute more to the total species richness. We emphasize the strong association between species richness and sampling efforts, and discuss the risks of invasive species. Our inventory is certainly incomplete as the ascidian fauna in many areas around the world is relatively poorly known, and many new species continue to be discovered and described each year
Epibenthic colonization on an artificial reef in a stressed environment off the north coast of the Rio de Janeiro State, Brazil
O niektórych porostach poznanych w okolicach Ribeiro Frio (Madera, Makaronezja)
A list of 49 lichens recently collected in the vicinity of Ribeiro Frio in Madeira is given. The species Ramalina nodosa and Peltigera neckeri are probably new to the island. Collections of Cladonia stereoclada, Hypogymnia madeirensis, Megalospora maderensis, Peltigera degenii and Phlyctis agelaea are interesting as well.Podano listę 49 gatunków porostów zebranych w latach 2008 i 2009 w okolicy siedziby Ribeiro Frio na wyspie Madera. Gatunki Ramalina nodosa i Peltigera neckeri są prawdopodobnie nowe dla tej wyspy; interesujące są równieź notowania gatunków Cladonia stereoclada, Hypogymnia madeirensis, Megalospora maderensis, Peltigera degenii i Phlyctis agelaea
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