245 research outputs found
Topology and confinement at T \neq 0 : calorons with non-trivial holonomy
In this talk, relying on experience with various lattice filter techniques,
we argue that the semiclassical structure of finite temperature gauge fields
for T < T_c is dominated by calorons with non-trivial holonomy. By simulating a
dilute gas of calorons with identical holonomy, superposed in the algebraic
gauge, we are able to reproduce the confining properties below T_c up to
distances r = O(4 fm} >> \rho (the caloron size). We compute Polyakov loop
correlators as well as space-like Wilson loops for the fundamental and adjoint
representation. The model parameters, including the holonomy, can be inferred
from lattice results as functions of the temperature.Comment: Talk by M. M\"uller-Preussker at "Quark Confinement and Hadron
Structure VII", Ponta Delgada, Azores, Portugal, September 2 - 7, 2006, 4
pages, 2 figures, to appear in the Proceeding
Pionic atoms probing pi-NN resonances
The pion optical potential generated by the hypothetical pi-NN-coupled
NN-decoupled dibaryon resonance d'(2065) is calculated to the lowest order in
nuclear matter density. The contribution to the pion optical potential is found
to be within the empirical errors, so the d'(2065) existence currently does not
contradict to the observed properties of the pi-nucleus bound states. Future
progress in the pionic X-ray spectroscopy can reveal contributions of pi-NN
resonances to energy levels and widths of the pionic atoms.Comment: 3 pages REVTEX, 1 ps figur
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