2,825 research outputs found
Uniqueness of infrared asymptotics in Landau gauge Yang-Mills theory
We uniquely determine the infrared asymptotics of Green functions in Landau
gauge Yang-Mills theory. They have to satisfy both,
Dyson-Schwinger equations and functional renormalisation group equations.
Then, consistency fixes the relation between the infrared power laws of these
Green functions. We discuss consequences for the interpretation of recent
results from lattice QCD.Comment: 24 pages, 8 figure
Gauge invariance, background fields and modified Ward identities
In this talk the gauge symmetry for Wilsonian flows in pure Yang-Mills
theories is discussed. The background field formalism is used for the
construction of a gauge invariant effective action. The symmetries of the
effective action under gauge transformations for both the gauge field and the
auxiliary background field are separately evaluated. Modified Ward-Takahashi
and background field identities are used in my study. Finally it is shown how
the symmetry properties of the full theory are restored in the limit where the
cut-off is removed.Comment: 6 pages, to appear in the Proceedings of the 2nd Conference on the
Exact Renormalization Group, Rome 200
QCD critical region and higher moments for three flavor models
One of the distinctive feature of the QCD phase diagram is the possible
emergence of a critical endpoint. The critical region around the critical point
and the path dependency of the critical exponents is investigated within
effective chiral (2+1)-flavor models with and without Polyakov-loops. Results
obtained in no-sea mean-field approximations where a divergent vacuum part in
the fermion-loop contribution is neglected, are confronted to the renormalized
ones. Furthermore, the modifications caused by the back-reaction of the matter
fluctuations on the pure Yang-Mills system are discussed. Higher order,
non-Gaussian moments of event-by-event distributions of various particle
multiplicities are enhanced near the critical point and could serve as a probe
to determine its location in the phase diagram. By means of a novel derivative
technique higher order generalized quark-number susceptibilities are calculated
and their sign structure in the phase diagram is analyzed.Comment: 12 pages, 11 figures. Final PRD version (references and one more
equation added
- âŠ