Wednesday, August 09, 2006

Lattice 2006 -- Summary

As threatened earlier, here is my personal review of the Lattice 2006 conference, in the form of an incomplete list of disjointed observations:

Driven by the RHIC data, QCD at finite temperature and/or chemical potential is rapidly becoming a leading subfield within lattice QCD; at this meeting, seven out of 22 plenary talks were about some aspect of QCD thermodynamics, and the number of parallel talks on "High temperature and density" topics was second only to that of the traditionally most numerous spectroscopy talks.

The debate about the validity of the fourth-root prescription for staggered fermions, which an anonymous observer called "the staggered wars", shows no sign of coming to an end. Although a lot of progress has been made recently towards showing the correctness of the rooting prescription, a number of unattractive features have been found at the same time, fueling the flames.

Progress regarding more accurate determinations of CKM matrix elements from lattice QCD is slow, but steady; a lot of this work is very difficult, since getting high precision requires good control over perturbative errors and chiral extrapolations, and both lattice perturbation theory and chiral perturbation theory are hard and suffer from a lack of practitioners.

The AdS/CFT correspondence is beginning to become a topic of interest to researchers working on QCD, and string theory returns to its origins in the strong interactions where it may become a helpful tool to build and solve models of QCD.

Dynamical simulations with overlap fermions are arriving, but it will be a while until they get to the range of lattice spacings, lattice sizes and quark masses that have been studied using staggered fermions.

Everyone will be able to form their own opinion on what was new, what was hot and what was not, once the proceeedings have been published by Proceedings of Science (and before that, when there will be a flood of new papers on the currently fairly quiet hep-lat arXiv).