111 research outputs found
The Chromo-Dielectric Soliton Model: Quark Self Energy and Hadron Bags
The chromo-dielectric soliton model (CDM) is Lorentz- and chirally-invariant.
It has been demonstrated to exhibit dynamical chiral symmetry breaking and
spatial confinement in the locally uniform approximation. We here study the
full nonlocal quark self energy in a color-dielectric medium modeled by a two
parameter Fermi function. Here color confinement is manifest. The self energy
thus obtained is used to calculate quark wave functions in the medium which, in
turn, are used to calculate the nucleon and pion masses in the one gluon
exchange approximation. The nucleon mass is fixed to its empirical value using
scaling arguments; the pion mass (for massless current quarks) turns out to be
small but non-zero, depending on the model parameters.Comment: 24 pages, figures available from the author
Hadronization of a Quark-Gluon Plasma in the Chromodielectric Model
We have carried out simulations of the hadronization of a hot, ideal but
effectively massive quark-gluon gas into color neutral clusters in the
framework of the semi-classical SU(3) chromodielectric model. We have studied
the possible quark-gluon compositions of clusters as well as the final mass
distribution and spectra, aiming to obtain an insight into relations between
hadronic spectral properties and the confinement mechanism in this model.Comment: 34 pages, 37 figure
A line confusion limited millimeter survey of Orion KL (I): sulfur carbon chains
We perform a sensitive (line confusion limited), single-side band spectral
survey towards Orion KL with the IRAM 30m telescope, covering the following
frequency ranges: 80-115.5 GHz, 130-178 GHz, and 197-281 GHz. We detect more
than 14 400 spectral features of which 10 040 have been identified up to date
and attributed to 43 different molecules, including 148 isotopologues and lines
from vibrationally excited states. In this paper, we focus on the study of OCS,
HCS+, H2CS, CS, CCS, C3S, and their isotopologues. In addition, we map the OCS
J=18-17 line and complete complementary observations of several OCS lines at
selected positions around Orion IRc2 (the position selected for the survey). We
report the first detection of OCS v2 = 1 and v3 = 1 vibrationally excited
states in space and the first detection of C3S in warm clouds. Most of CCS, and
almost all C3S, line emission arises from the hot core indicating an
enhancement of their abundances in warm and dense gas. Column densities and
isotopic ratios have been calculated using a large velocity gradient (LVG)
excitation and radiative transfer code (for the low density gas components) and
a local thermal equilibrium (LTE) code (appropriate for the warm and dense hot
core component), which takes into account the different cloud components known
to exist towards Orion KL, the extended ridge, compact ridge, plateau, and hot
core. The vibrational temperature derived from OCS v2 = 1 and v3 = 1 levels is
about 210 K, similar to the gas kinetic temperature in the hot core. These OCS
high energy levels are probably pumped by absorption of IR dust photons. We
derive an upper limit to the OC3S, H2CCS, HNCS, HOCS+, and NCS column
densities. Finally, we discuss the D/H abundance ratio and infer the following
isotopic abundances: 12C/13C=45+-20, 32S/34S=20+-6, 32S/33S=75+-29, and
16O/18O=250+-135.Comment: Accepted for publication in A&
Quantum liquids resulting from quark systems with four-quark interaction
Quark ensembles influenced by strong stochastic vacuum gluon fields are investigated within the four-fermion interaction approximation. The comparative analysis of several quantum liquid models is performed and this analysis leads to the conclusion that the presence of a gas–liquid phase transition is their characteristic feature. The problem of the instability of small quark number droplets is discussed and it is argued that it is rooted in the chiral soliton formation. The existence of a mixed phase of the vacuum and baryon matter is proposed as a possible explanation of the latter stability
REAL-TIME DESCRIPTION OF PARTON-HADRON CONVERSION AND CONFINEMENT DYNAMICS
We propose a new and universal approach to the hadronization problem that
incorporates both partonic and hadronic degrees of freedom in their respective
domains of relevance, and that describes the conversion between them within a
kinetic field theory formulation in real time and full 7-dimensional phase
space. We construct a scale-dependent effective theory that reduces to
perturbative QCD with its scale and chiral symmetry properties at short
space-time distances, but at large distances (r > 1 fm) yields symmetry
breaking gluon and quark condensates plus hadronic excitations. The approach is
applied to the evolution of fragmenting qq~ and gg jet pairs as the system
evolves from the initial 2-jet configuration, via parton showering and cluster
formation, to the final yield of hadrons. The phenomenological implications for
e+e- -> hadrons are investigated, such as the time scale of the transition, and
its energy dependence, cluster size and mass distributions. We compare our
results for particle production and Bose-Einstein correlations with
experimental data, and find an interesting possibility of extracting the basic
parameters of the space-time evolution of the system from Bose enhancement
measurements.Comment: 51 pages, latex, 14 figures as uu-encoded postscript file
Experimentelle Forschung über das Wesen der periodischen Extremitätenlähmung mit besonderer Berücksichtigung der Ursache der Lähmungsanfälle und des Wirkungsmechanismus der Mehrzufuhr von Kohlehydraten als anfallauslösendes Moment
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