18,395 research outputs found
Applications of Nonrelativistic Effective Field Theories to quarkonium systems with a small radius
We review some predictions of nonrelativistic effective field theories for
heavy quark-antiquark systems with a small typical radius, r<1/\Lambda_QCD.Comment: 4 pages, uses espcrc2.sty, talk given at the BEACH2002 Conference,
Vancouver, June 200
Effective Field Theories for Heavy Quarkonium
We briefly review how nonrelativistic effective field theories give us a
definition of the QCD potentials and a coherent field theory derived quantum
mechanical scheme to calculate the properties of bound states made by two or
more heavy quarks. In this framework heavy quarkonium properties depend only on
the QCD parameters (quark masses and \als) and nonpotential corrections are
systematically accounted for. The relation between the form of the
nonperturbative potentials and the low energy QCD dynamics is also discussed.Comment: Invited Plenary talk at The 20th European Conference on Few-Body
Problems in Physics. September 10-14 2007. Pisa, Italy. To be published on
Few-Body System
New results on inclusive quarkonium decays
I review some recent progress, leading to a substantial reduction in the
number of non-perturbative parameters, in the calculation of inclusive
quarkonium decay widths in the framework of non-relativistic effective field
theories.Comment: 4 pages, 3 figures, to be published in the proceedings of the
XXXVIIth Rencontres de Moriond (QCD and High Energy Hadronic Interactions),
16-23 March 2002, Les Arcs, Franc
Three-body relativistic flux tube model from QCD Wilson-loop approach
First we review the derivation of the relativistic flux tube model for a
quark-antiquark system from Wilson area law as we have given in a preceding
paper. Then we extend the method to the three-quark case and obtain a
Lagrangian corresponding to a star flux tube configuration.
A Hamiltonian can be explicitly constructed as an expansion in or
in the string tension . In the first case it reproduces the Wilson loop
three-quark semirelativistic potential; in the second one, very complicated in
general, but it reproduces known string models for slowly rotating quarks.Comment: 14 pages, latex, uses elsart.sty, 2 figures available upon reques
The relativistic interaction in the Wilson loop approach
We study the relativistic interaction starting from the
Feynman-Schwinger representation of the gauge-invariant quark-antiquark Green
function. We focus on the one-body limit and discuss the obtained
non-perturbative interaction kernel of the Dirac equation.Comment: 5 pages, Latex (espcrc2.sty) To be published in the proceedings of
High-Energy Physics International Euroconference on Quantum
Chromodynamics:QCD97; 25th Anniversary of QCD, Montpellier, France, 3-9 July
199
The non-perturbative QCD potential
The potential between heavy quarks can be rigorously defined in a QCD
effective field theories framework. I discuss the general situation when the
coupling constant may not be considered small and provide an explicit
expression for the potential valid up to order 1/m^2. Spin dependent and spin
independent terms are expressed in terms of Wilson loops, completing an ideal
journey started twenty years ago with the classical work of Eichten and
Feinberg.Comment: 8 pages, 1 figure, espcrc2.sty. Invited talk given at QCD00, 6-13
July, Montpellier, France and at the XIII International Workshop on the
Fundamental Problems of High Energy Physics and Field Theory, 21-23 June,
Protvino, Russia. To be published in Nucl. Phys. Proc. Supp
Probing the QCD vacuum
Heavy quark bound states are used as significative probes of the QCD vacuum
and the mechanism of confinement.Comment: 13 pages, sprocl.sty, 2 figures, Invited talk given at the XVIII
Autumn School ``Topology of Strongly Correlated Systems'', Lisbon, Portugal,
8-13 October, 200
Optical fibre nanowire technology and applications
A review of optical fibre nanowires and their applications is presented
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