3,828 research outputs found
Could Spin-Charge Separation be the Source of Confinement?
Yang-Mills gauge field with gauge group SU(2) decomposes into a single charge
neutral complex vector, and two spinless charged scalar fields. At high
energies these constituents are tightly confined into each other by a compact
U(1) interaction, and the Yang-Mills Lagrangian describes the dynamics of
asymptotically free massless gauge vectors. But in a low energy and finite
density environment the interaction between the constituents can become weak,
and a spin-charge separation may occur. We suggest that the separation between
the spin and charge with the ensuing condensation of the charged scalars takes
place when the Yang-Mills theory enters confinement. The confining phase
becomes then surprisingly similar to the superconducting phase of a high-
superconductor.Comment: Talk presented at QCD@Work 2005 (Conversano
Are Glueballs Knotted Closed Strings?
Glueballs have a natural interpretation as closed strings in Yang-Mills
theory. Their stability requires that the string carries a nontrivial twist, or
then it is knotted. Since a twist can be either left-handed or right-handed,
this implies that the glueball spectrum must be degenerate. This degeneracy
becomes consistent with experimental observations, when we identify the
component of the pseudoscalar as a
glueball, degenerate in mass with the widely accepted glueball
. In addition of qualitative similarities, we find that these two
states also share quantitative similarity in terms of equal production ratios,
which we view as further evidence that their structures must be very similar.
We explain how our string picture of glueballs can be obtained from Yang-Mills
theory, by employing a decomposed gauge field. We also consider various
experimental consequences of our proposal, including the interactions between
glueballs and quarks and the possibility to employ glueballs as probes for
extra dimensions: The coupling of strong interactions to higher dimensions
seems to imply that absolute color confinement becomes lost.Comment: Talk given at International Symposium on Color Confinement and
Hadrons in Quantum Chromodynamics - Confinement 2003, Wako, Japan, 21-24 Jul
200
Topological Sigma-model, Hamiltonian Dynamics and Loop Space Lefschetz Number
We use path integral methods and topological quantum field theory techniques
to investigate a generic classical Hamiltonian system. In particular, we show
that Floer's instanton equation is related to a functional Euler character in
the quantum cohomology defined by the topological nonlinear --model.
This relation is an infinite dimensional analog of the relation between
Poincar\'e--Hopf and Gauss--Bonnet--Chern formul\ae in classical Morse
theory, and can also be viewed as a loop space generalization of the Lefschetz
fixed point theorem. By applying localization techniques to path integrals we
then show that for a K\"ahler manifold our functional Euler character coincides
with the Euler character determined by the finite dimensional de Rham
cohomology of the phase space. Our results are consistent with the Arnold
conjecture which estimates periodic solutions to classical Hamilton's equations
in terms of de Rham cohomology of the phase space.Comment: 10 pages, LaTEX. New title and some modifications in the text.
Version to appear in Phys. Lett.
Elliptic flow from event-by-event hydrodynamics
We present an event-by-event hydrodynamical framework which takes into
account the initial density fluctuations arising from a Monte Carlo Glauber
model. The elliptic flow is calculated with the event plane method and a
one-to-one comparison with the measured event plane is made. Both the
centrality- and -dependence of the are remarkably well reproduced.
We also find that the participant plane is a quite good approximation for the
event plane.Comment: 4 pages, 3 figures. Talk given at Quark Matter 2011, 22-28 May 2011,
Annecy, Franc
On Exact Evaluation of Path Integrals
Some mistakes have been correcte
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