7,204 research outputs found
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
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 Role of the QCD Vacuum in the Heavy-Quark Bound State Dynamics
The effective field theory approach allows a rigorous disentangling of high
and low energy effects in the heavy quarkonium dynamics. Focusing in particular
on the spectrum, we describe the nature of the non-perturbative effects and
discuss our present knowledge of them.Comment: Invited talk presented at the Fifth Workshop on Quantum
Chromodynamics, Villefranche-sur-Mer, France, 3-7 January 2000; 9 pages,
sprocl.st
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 1P quarkonium fine splittings at NLO
We calculate the 1P heavy quarkonium fine splittings at NLO and discuss the
impact of the calculation on the chi_b(1P) splittings.Comment: 10 pages, 3 figure
Effective field theories for baryons with two- and three-heavy quarks
Baryons made of two or three heavy quarks can be described in the modern
language of non-relativistic effective field theories. These, besides allowing
a rigorous treatment of the systems, provide new insight in the nature of the
three-body interaction in QCD.Comment: 7 pages, 1 figure; published versio
α<sub>S1</sub>-casein in goat milk: identification of genetic variants by Capillary Zone Electrophoresis compared to Isoelectric Focusing
AlphaS1 casein fraction in caprine milk is characterized by an important polymorphism due to substitution, deletion of amino acids and post trascriptional modifications (Grosclaude et al., 1994; Ferranti et al., 1997). This structural polymorphism is associated to a quantitative variability
in protein expression related to different milk quality and dairy properties (Pierre et al., 1998; Remeuf, 1993; Vassal et al., 1994). Classical electrophoretic methods were applied to characterize the phenotypic variants at αS1-casein fraction (Addeo et al., 1988; Russo et al., 1986). During the last ten years capillary electrophoresis became an analytical technique for rapid and automated analysis requiring
small sample volume and small solvent waste. These characteristics, together with the high resolution
and the chance to give quantitative results, made this technique a useful tool in studying milk protein
characterization and in detecting adulteration (Cattaneo et al., 1996a; 1996b) in different application
fields. CZE was applied to the study of caprine milk proteins to quantify high, medium and low αS1-
casein content and to identify genetic variants αS1 A, B and C on the basis of their different migration time (Recio et al., 1997). The aim of this work was to test a CZE procedure able to identify and discriminate the main αS1 caprine variants A, B, E and F through specific and repeatable electromigration patterns. Comparison between CZE and IEF assays is discussed
Heavy Quarkonium Physics from Effective Field Theories
I review recent progress in heavy quarkonium physics from an effective field
theory perspective. In this unifying framework, I discuss advances in
perturbative calculations for low-lying quarkonium observables and in lattice
calculations for high-lying ones, and progress and lasting puzzles in
quarkonium production.Comment: Plenary talk at the 4th International Conference on Quarks and
Nuclear Physics (QNP06), 5-10 June 2006, Madrid, Spain; 6 pages, 1 figure,
EPJ styl
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