839 research outputs found
Comparison of turbulence measurements and simulations of the low-temperature plasma in the torsatron TJ-K
A toroidal low-temperature plasma is used for comparative turbulence studies. Measurements are carried out with Langmuir probe arrays in the entire plasma cross section. The data are closely compared with drift-Alfven turbulence simulations. Although the parameters in a low-temperature plasma are very different from those in fusion plasmas, the dimensionless parameters governing the drift-wave physics are comparable. Hence this study can also give insight into high-temperature plasma turbulence. In order to identify relevant characteristic signatures of different turbulence-driving mechanisms, simulations were carried out for a wide range of plasma parameters. The simulation results are compared with first measurements
Effects of Dirac sea polarization on hadronic properties - A chiral SU(3) approach
The effect of vacuum fluctuations on the in-medium hadronic properties is
investigated using a chiral SU(3) model in the nonlinear realization. The
effect of the baryon Dirac sea is seen to modify hadronic properties and in
contrast to a calculation in mean field approximation it is seen to give rise
to a significant drop of the vector meson masses in hot and dense matter. This
effect is taken into account through the summation of baryonic tadpole diagrams
in the relativistic Hartree approximation (RHA), where the baryon self energy
is modified due to interactions with both the non-strange and the
strange scalar fields.Comment: 25 pages including 13 figures,figure styles modified,few clarifying
sentences added in text, to appear in Phys. Rev.
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