From QCD to Dual Superconductivity to Effective String Theory

We show how an effective field theory of long distance QCD, describing a dual superconductor, can be expressed as an effective string theory of superconducting vortices. We use the semiclassical expansion of this effective string theory about a classical rotating string solution in any spacetime dimension D to obtain the semiclassical meson energy spectrum. We argue that the experimental data on Regge trajectories along with numerical simulations of the heavy quark potentials provide good evidence for an effective string description of long distance QCD.Comment: Talk given at the 5th International Conference on Quark Confinement and the Hadron Spectrum, Gargnano, Italy, September 200

Effective Field Theory for Long Strings

In previous work we used magnetic SU(N) gauge theory with adjoint representation Higgs scalars to describe the long distance quark-antiquark interaction in pure Yang-Mills theory, and later to obtain an effective string theory. The empirically determined parameters of the non-Abelian effective theory yielded $Z_N$ flux tubes resembling those of the Abelian Higgs model with Landau-Ginzburg parameter equal to $1/\sqrt{2}$, corresponding to a superconductor on the border between type I and type II. However, the physical significance of the differences between the Abelian and the $Z_N$ vortices was not elucidated and no principle was found to fix the value of the 'Landau-Ginzburg parameter' $\kappa$ of the non-Abelian theory determining the structure of the $Z_N$ vortices. Here we reexamine this point of view. We propose a consistency condition on $Z_N$ vortices underlying a confining string. This fixes the value of $\kappa$. The transverse distribution of pressure $p(r)$ in the resulting $Z_N$ flux tubes provides a physical picture of these vortices which differs essentially from that of the vortices of the Abelian Higgs model. We speculate that this general picture is valid independent of the details of the effective magnetic gauge theory from which it was obtained. Long wavelength fluctuations of the axis of the $Z_N$ vortices lead from an effective field theory to an effective string theory with the Nambu-Goto action. This effective string theory depends on a single parameter, the string tension $\sigma$. In contrast, the effective field theory has a second parameter, the intrinsic width 1/M of the flux tube.Comment: 8 page, 2 figure

A universal solution

The phenomenon of an implicit function which solves a large set of second order partial differential equations obtainable from a variational principle is explicated by the introduction of a class of universal solutions to the equations derivable from an arbitrary Lagrangian which is homogeneous of weight one in the field derivatives. This result is extended to many fields. The imposition of Lorentz invariance makes such Lagrangians unique, and equivalent to the Companion Lagrangians introduced in [baker].Comment: arxiv version is already officia

Effective String Theory of Vortices and Regge Trajectories

Starting from a field theory containing classical vortex solutions, we obtain an effective string theory of these vortices as a path integral over the two transverse degrees of freedom of the string. We carry out a semiclassical expansion of this effective theory, and use it to obtain corrections to Regge trajectories due to string fluctuations.Comment: 27 pages, revtex, 3 figures, corrected an error with the cutoff in appendix E (was previously D), added more discussion of Fig. 3, moved some material in section 9 to a new appendi

Effective String Theory of Vortices and Regge Trajectories of Hybrid Mesons with Zero Mass Quarks

We show how a field theory containing classical vortex solutions can be expressed as an effective string theory of long distance QCD describing the two transverse oscillations of the string. We use the semiclassical expansion of this effective string theory about a classical rotating string solution to obtain Regge trajectories for mesons with zero mass quarks. The first semiclassical correction adds the constant 1/12 to the classical Regge formula for the angular momentum of mesons on the leading Regge trajectory. In D spacetime dimensions, this additive constant is (D-2)/24. The excited states of the rotating string give rise to daughter Regge trajectories determining the spectrum of hybrid mesons.Comment: 12 pages, 2 figures, LaTeX, style file include

Using Email Communication to Increase Expatriate Parents' Knowledge of the Human Papillomavirus

Expatriates face a unique set of determinants to health which may influence their level of knowledge, perception of available preventative health care alternatives and their health seeking behaviors. The objective of this study is to understand the effect of an email communication intervention on expatriate parents' level of knowledge of the Human Papillomavirus (HPV). Repeated measurement of knowledge was conducted pre- and post-intervention among parents who received the study intervention (group 1) and those who received standard care (group 2). Intervention effect was measured by any change in knowledge within and between groups. The group 1 had a significant rise in knowledge mean from baseline to first and then second follow-up (m = 0.57 (SD 0.39), m = 0.84 (SD 0.16) and m = 0.87 (SD 0.11), respectively). In addition, after receiving the intervention, group 1 felt they had sufficient information to make an informed decision of whether to vaccinate their child(ren), with a significant difference from baseline to first post test, (χ² (1) = 8.50, p < 0.05). Based on an increase in knowledge, the study's email intervention proved effective mode to disseminating HPV-related information