3,189 research outputs found
Jets in 200 GeV p+p and d+Au collisions from the STAR experiment at RHIC
Full jet reconstruction in heavy-ion collisions is a promising tool for the
quantitative study of properties of the dense medium produced at RHIC.
Measurements of d+Au collisions are important to disentangle initial state
nuclear effects from medium-induced kT broadening and jet quenching. Study of
jet production and properties in d+Au in combination with similar studies in
p+p is an important baseline measurement needed to better understand heavy-ion
results. We present mid-rapidity inclusive jet pT spectra and di-jet
correlations (kT) in 200 GeV p+p and d+Au collisions from the 2007-2008 RHIC
run. We discuss the methods used to correct the data for detector effects and
for background in d+Au collisions.Comment: 4 pages, 5 figures. To appear in Hot Quarks 2010 conference
proceeding
Overview on jet results from STAR
Full jet reconstruction allows access to the parton kinematics over a large
energy domain and can be used to constrain the mechanisms of energy loss in
heavy-ion collisions. Such measurements are challenging at RHIC, due to the
high-multiplicity environments created in heavy-ion collisions. In these
proceedings, we report an overview of the results on full jet reconstruction
obtained by the STAR experiment. Jet measurements in 200 GeV p+p show that jets
are calibrated pQCD probes and provide a baseline for jet measurements in Au+Au
collisions. Inclusive differential jet production cross sections and ratios are
reported for central 200 GeV Au+Au collisions and compared to p+p. We also
present measurements of fully reconstructed di-jets at mid-rapidity, and
compare spectra and fragmentation functions in p+p and central Au+Au
collisions.Comment: Proceedings for the 26th WWND conferenc
Carrier mobility and scattering lifetime in electric double-layer gated few-layer graphene
We fabricate electric double-layer field-effect transistor (EDL-FET) devices
on mechanically exfoliated few-layer graphene. We exploit the large capacitance
of a polymeric electrolyte to study the transport properties of three, four and
five-layer samples under a large induced surface charge density both above and
below the glass transition temperature of the polymer. We find that the carrier
mobility shows a strong asymmetry between the hole and electron doping regime.
We then employ ab-initio density functional theory (DFT) calculations to
determine the average scattering lifetime from the experimental data. We
explain its peculiar dependence on the carrier density in terms of the specific
properties of the electrolyte we used in our experiments.Comment: 6 pages, 3 figure
Vertex reconstruction for proton-proton collisions in ALICE
Reconstructing the interaction vertex is a challenging task in the low multiplicity environment of pp collisions at the LHC. The two innermost layers of the Inner Tracking System (ITS), made of pixels, allow to obtain a first estimate of the vertex position, which can be provided also in a quasi-online mode, since only the local reconstruction is used. The optimal vertex measurement is obtained after the full event processing, using the tracks reconstructed in the ALICE barrel detectors. We present the methods for primary vertex reconstruction in pp collisions using pixels and tracks reconstructed in the ITS+TPC or in the TPC only. We also show the performance of the vertex finder in reconstructing displaced vertices originated by short-lived particles like charmed mesons
The role of roadsides in conserving Cerrado plant diversity
Abstract The structure of Cerrado vegetation (sensu stricto) along roadsides was compared with that of protected areas (reserves). The superior stratum of reserves had 2.7 times more individuals and 1.4 times more species than on roadsides, while in the intermediate stratum there were 1.7 times more individuals and 25 % more species in reserves. Additionally, roadsides had a lower prevalence of tree species with thin bark and from forest physiognomies. In the intermediate stratum of roadsides there was a lower proportion of forest species, and also fewer species dispersed by animals. These differences occur, possibly because the vegetation of their edges is cleared during the construction of the roads and part of the soil is taken as landfill. Later, they suffer from a higher fire frequency and high coverage of exotic grasses (80 % average). Moreover, it is likely that the absence of some dispersers on roadsides may affect the recruitment of young plants. Despite these differences, the roadsides are able to maintain at least 70 % of tree species and 72 % of shrub species found in reserves. These results show that roadside vegetation can contribute 123 Biodivers Conserv (2014) 23:3035-3050 DOI 10.1007 to the conservation of the flora of Cerrado. This is particularly important considering that over 60 % of the original area of this ecosystem has been destroyed and that less than 4 % is protected. With 32,012 km of roads in the Cerrado alone, the roadside vegetation may represent a cumulative area of 96,000 of hectares, an area larger than many of the Cerrado's national parks
First record of Ostracod ingestion by adult frogs
The marsupial frog Fritziana goeldii is an endemic species of Brazil with few aspects of its habits reported in the literature. In this work, we report for the first time the ingestion of Elpidium sp., an ostracod that lives in bromeliads which is known to use amphibians as vectors for phoresy, by F. goeldii. It is also the first time that this group is reported in the digestive tract of an adult amphibian.Asociación Herpetológica Argentin
First record of Ostracod ingestion by adult frogs
The marsupial frog Fritziana goeldii is an endemic species of Brazil with few aspects of its habits reported in the literature. In this work, we report for the first time the ingestion of Elpidium sp., an ostracod that lives in bromeliads which is known to use amphibians as vectors for phoresy, by F. goeldii. It is also the first time that this group is reported in the digestive tract of an adult amphibian.Asociación Herpetológica Argentin
First record of Ostracod ingestion by adult frogs
The marsupial frog Fritziana goeldii is an endemic species of Brazil with few aspects of its habits reported in the literature. In this work, we report for the first time the ingestion of Elpidium sp., an ostracod that lives in bromeliads which is known to use amphibians as vectors for phoresy, by F. goeldii. It is also the first time that this group is reported in the digestive tract of an adult amphibian.Asociación Herpetológica Argentin
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