Screening effects in QCD and renormalization of Hamiltonian.
Item
-
Title
-
Screening effects in QCD and renormalization of Hamiltonian.
-
Identifier
-
AAI9946131
-
identifier
-
9946131
-
Creator
-
Alexanian, Garnik G.
-
Contributor
-
Adviser: V. Parameswaran Nair
-
Date
-
1999
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Physics, Elementary Particles and High Energy | Mathematics
-
Abstract
-
Part I of this thesis discusses various screening effects in Quantum Chromodynamics. We start with the Thomas-Fermi screening of non-Abelian gauge fields by fermions or screening of gluon fields in quark matter. It is shown that it can be described by an effective mass term which is, as with hard thermal loops, related to the eikonal for a Chern-Simons theory and the Wess-Zumino-Witten action. Using this connection we discuss how another type of screening (magnetic) can be systematically included in a self-consistent way for Chromodynamics at high temperatures. The resulting gap equation, which gives the summation of self-energy insertions, is calculated to one-loop order and leads to a nonzero value for the magnetic mass.;In the Part II of this thesis we introduce a novel method for the renormalization of the Hamiltonian operator in Quantum Field Theory in the spirit of the Wilson renormalization group. By a series of unitary transformations that successively decouple the high-frequency degrees of freedom and partially diagonalize the high-energy part, we obtain the effective Hamiltonian for the low energy degrees of freedom. We successfully apply this technique to compute the 2-loop renormalized Hamiltonian in scalar lambda &phis;4 theory. Using this method to construct 1-loop renormalized Hamiltonians for Yang-Mills theory and Quantum electrodynamics we study the connection between asymptotic freedom and the renormalization group flow of the configuration space metric. It is argued that in asymptotically free theories the effective distance between configurations decreases as high momentum modes are integrated out.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
