35,292 research outputs found
What is the temperature in heavy ion collisions?
We consider the Tsallis distribution as the source of the apparent slope of
one-particle spectra in heavy-ion collisions and investigate the equation of
state of this special quark matter in the framework of non-extensive
thermodynamics.Comment: Talk given by T.S.Biro at RHIC School 2003, Dec.8-11, 2003, Budapest,
Hungar
Development of a floating tidal energy system suitable for use in shallow water
A proposal is made for the use of a traditional streamwaterwheel suspended between two floating catamaranNPL series demi-hulls as means of generating electricalpower. Two prototype devices, of lengths 1.6m and 4.5m,have been developed, constructed and tested. It was foundthat the concept is sound although greater investment isrequired with regards to the materials and bothhydrodynamic and aerodynamic design of the waterwheelto ensure an economically viable system. The workpresented concentrates on practical aspects associated withdesign, construction and trial testing in Southampton waterof the 4.5m prototype. The relatively low cost, ease ofdeployment, and the fact that conventional boat mooringsystems are effective, combine to make this an attractivealternative energy solution for remote communities
Jet Modification in a Brick of QGP Matter
We have implemented the LPM effect into a microscopic transport model with
partonic degrees of freedom by following the algorithm of Zapp & Wiedemann. The
Landau-Pomeranchuk-Migdal (LPM) effect is a quantum interference process that
modifies the emission of radiation in the presence of a dense medium. In QCD
this results in a quadratic length dependence for radiative energy loss. This
is an important effect for the modification of jets by their passage through
the QGP.
We verify the leading parton energy loss in the model against the leading
order Baier-Dokshitzer-Mueller-Peigne-Schiff-Zakharov (BDMPS-Z) result.
We apply our model to the recent observations of the modification of di-jets
at the LHC.Comment: Presented at Panic 1
Molecular tendrils feeding star formation in the Eye of the Medusa - The Medusa merger in high resolution 12CO 2-1 maps
Studying molecular gas properties in merging galaxies gives us important
clues to the onset and evolution of interaction-triggered starbursts. NGC4194
is particularly interesting to study since its FIR-to-CO luminosity ratio
rivals that of ULIRGs,despite its lower luminosity compared to ULIRGs, which
indicates a high star formation efficiency that is relative to even most
spirals and ULIRGs.We study the molecular medium at an angular resolution of
0.65"x .52" through our observations of CO2-1 emission using the SMA. We
compare our CO2-1 maps with optical HST and high angular resolution radio
continuum images to study the relationship between molecular gas and other
components of the starburst region. The molecular gas is tracing the
complicated dust lane structure of NGC4194 with the brightest emission being
located in an off-nuclear ring-like structure with ~320pc radius, the Eye of
the Medusa. The bulk CO emission of the ring is found south of the kinematical
center of NGC4194. The northern tip of the ring is associated with the galaxy
nucleus, where the radio continuum has its peak. A prominent, secondary
emission maximum in the radio continuum is located inside the molecular ring.
This suggests that the morphology of the ring is partially influenced by
massive supernova explosions. From the combined evidence, we propose that the
Eye of the Medusa contains a shell of swept up material where we identify a
number of giant molecular associations. We propose that the Eye may be the site
of an efficient starburst of 5-7M_sun/yr, but it would still constitute only a
fraction of the 30-50M_sun/yr SFR of NGC4194. Furthermore, we find that ~50% of
the molecular mass of NGC4194 is found in extended filamentary-like structures
tracing the minor and major axis dust lanes. We suggest that molecular gas is
transported along these lanes providing the central starburst region with fuel.Comment: accepted for publication in A&A, 12 pages, 9 figure
A relativistic quark model for the Omega- electromagnetic form factors
We compute the Omega- electromagnetic form factors and the decuplet baryon
magnetic moments using a quark model application of the Covariant Spectator
Theory. Our predictions for the Omega- electromagnetic form factors can be
tested in the future by lattice QCD simulations at the physical strange quark
mass.Comment: 13 pages, 5 figure
Investigation of marmoset hybrids (Cebuella pygmaea x Callithrix jacchus) and related Callitrichinae (Platyrrhini) by cross-species chromosome painting and comparative genomic hybridization
We report on the cytogenetics of twin offspring from an interspecies cross in marmosets (Callitrichinae, Platyrrhini), resulting from a pairing between a female Common marmoset (Callithrix jacchus, 2n = 46) and a male Pygmy marmoset (Cebuella pygmaea, 2n = 44). We analyzed their karyotypes by multi-directional chromosome painting employing human, Saguinus oedipus and Lagothrix lagothricha chromosome-specific probes. Both hybrid individuals had a karyotype with a diploid chromosome number of 2n = 45. As a complementary tool, interspecies comparative genomic hybridization (iCGH) was performed in order to screen for genomic imbalances between the hybrids and their parental species, and between Callithrix argentata and S. oedipus, respectively. Copyright (C) 2005 S. Karger AG, Basel
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