15 research outputs found
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
Production of pions, kaons and protons in pp collisions at GeV with ALICE at the LHC
The production of , , , , p, and pbar at mid-rapidity
has been measured in proton-proton collisions at GeV with the
ALICE detector. Particle identification is performed using the specific energy
loss in the inner tracking silicon detector and the time projection chamber. In
addition, time-of-flight information is used to identify hadrons at higher
momenta. Finally, the distinctive kink topology of the weak decay of charged
kaons is used for an alternative measurement of the kaon transverse momentum
() spectra. Since these various particle identification tools give
the best separation capabilities over different momentum ranges, the results
are combined to extract spectra from = 100 MeV/ to 2.5 GeV/.
The measured spectra are further compared with QCD-inspired models which yield
a poor description. The total yields and the mean are compared with
previous measurements, and the trends as a function of collision energy are
discussed.Comment: 24 pages, 18 captioned figures, 5 tables, published version, figures
at http://aliceinfo.cern.ch/ArtSubmission/node/388
LMC N113 and N159W ALMA para-H_2_CO datacubes
We mapped the kinetic temperature structure of two massive star-forming regions, N113 and N159W, in the Large Magellanic Cloud (LMC). We have used ∼1.6" (∼0.4pc) resolution measurements of the para-H2CO JKaKc=303-202, 322-221, and 321-220 transitions near 218.5GHz to constrain RADEX non local thermodynamic equilibrium models of the physical conditions. The gas kinetic temperatures derived from the para-H2CO line ratios 322-221/303-202 and 321-220/303-202 range from 28 to 105K in N113 and 29 to 68K in N159W. Distributions of the dense gas traced by para-H2CO agree with those of the 1.3mm dust and Spitzer 8.0um emission, but they do not significantly correlate with the H emission. The high kinetic temperatures (Tkin≳50K) of the dense gas traced by para-H2CO appear to be correlated with the embedded infrared sources inside the clouds and/or young stellar objects in the N113 and N159W regions. The lower temperatures (Tkin<50K) were measured at the outskirts of the H2CO-bearing distributions of both N113 and N159W. It seems that the kinetic temperatures of the dense gas traced by para-H2CO are weakly affected by the external sources of the Hα emission. The non thermal velocity dispersions of para-H2CO are well correlated with the gas kinetic temperatures in the N113 region, implying that the higher kinetic temperature traced by para-H2CO is related to turbulence on a ∼0.4pc scale. The dense gas heating appears to be dominated by internal star formation activity, radiation, and/or turbulence. It seems that the mechanism heating the dense gas of the star-forming regions in the LMC is consistent with that in Galactic massive star-forming regions located in the Galactic plane
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Not AvailableThe increasing demand for crop production, given worldwide increases in the human population, puts pressure on moving natural resources towards sus-tainable development. This creates a big challenge for the upcoming generation. If improvement is not successful, there exists the unfortunate consequence that global food production may soon become insufficient to feed all of the world’s people. It is therefore essential that agricultural productivity be significantly increased in a more sustainable and environmentally friendly approach. Plant-beneficiary rhizo-bacteria (PBR) naturally activate microorganisms found in the soil. Because they are inexpensive, effective, and environmentally friendly, PBR are gaining impor-tance for use in crop production by restoring the soil’s natural fertility and protect-ing it against drought and soil diseases, thereby stimulating plant growth. PBR decrease the use of chemical fertilisers, pesticides, and artificial growth regulators; the intensive use of these inputs has led to severe health and environmental hazards, such as soil erosion, water contamination, pesticide poisoning, decreased ground-water table, water logging, surface crusting and depletion of biodiversity. The use of PBR has been proven to be an environmentally sound way of increasing crop yields by facilitating plant growth through either a direct or indirect mechanism with the aim of sustaining soil health over the long term.
(7) (PDF) Towards Plant-Beneficiary Rhizobacteria and Agricultural Sustainability. Available from: https://www.researchgate.net/publication/325854138_Towards_Plant-Beneficiary_Rhizobacteria_and_Agricultural_Sustainability [accessed Nov 19 2018].Not Availabl