Hello again from Dublin. Day two of Lattice 2005 was the "busy" day,

with three plenary sessions, a parallel session, and the poster

session all in one day. Twelve solid hours of physics, which is

rather tiring, particularly since I was presenting a poster. As such,

today's update of the Plenary sessions will be brief.

The morning started off with a talk by Herbert Neuberger on simulations

of large N field theory. As discovered by 't Hooft, SU(N) gauge

theory simplifies as you take the limit N -> infinity. However, this

is hard to do in Lattice QCD, as you would need infinite sized

matrices. However, there are techniques for attacking the problem.

Neuberger reviewed the interesting phase structure you see in this

system. The lattice version of large N QCD has 6 different phases.

Next up was Simon Catterall, who reviewed his work on Lattice

supersymmetry. In the early days of both supersymmetry and lattice

QCD, it wasn't thought possible to put a supersymetric theory on the

lattice without badly breaking the supersymmetry. However in recent

years, a few different methods have been discovered. The basic idea

is you construct a continuum theory with lots of supersymmetry and

arrange things such that when you put the theory on the lattice, a

remmenant of the supersymmetry remains. Simon reviewed his method for

doing this, and briefly touched on some of the possible applications

of these methods.

After a coffee break, the sessions shifted in focus a little bit.

Chris Dawson reviewed the state of Kaon Phenomenology on the lattice.

The focus here is on kaon decays, which are hard to do in lattice

QCD. For example, a kaon can decay into two pions. This is extremely

hard to compute, since pions are very large, it's hard to fit two of

them inside your finite lattice box.

We swapped last names for the next talk, Chris Dawson became Chris

Michael, who gave a lively review of the state of hadronic decays on

the lattice. The people I work with are interested in doing very high

precision calculations. This is good, however, it limits you to a

small number of thing you can calculate. However lattice QCD can, in

principle, calculate many many more interesting strong interaction

processes. Chris gave an update of the state of some of these

calculations, which are very very hard to do. You have an unstable

particle in the intitial state, two or more hadrons in the final

state, and a transition at some point between. I

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