Wednesday, May 24, 2006

Calling lattice bloggers!

As pointed out in Matthew's last post so far, this is the world's first (and only, hence best) group blog devoted to Lattice QCD. Unfortunately, Matthew's new job does not leave him too much time for blogging; therefore I'm running this blog all alone at the moment, which leads to the relatively low activity seen in recent weeks.

So I was wondering if there are any other lattice people out there who would like to join this blog and post here about their research work, the most recent papers on the arXiv or in the journals, interesting developments in the field, science in the news, and any other matters appropriate for a physics blog (as opposed to a mere physicists' blog). It would be great if this blog saw a little more activity!


Mike Creutz said...

you might mention this on latticenews:

Michael said...

I'm not knowledgable about lattuce gauge calculations, but am intrigued by a statement I heard at a recent physics colloquium. Apparently the masses of all of the lighter meson states can now be computed successfully from first principles -- all that is needed is Lambda_QCD or some equivalent mass scale. The speaker went on to say that QCD is the perfect theory since it has no adjustible or arbitrary parameters (aside from an overall scale) and is, of course, completely supported by experiment. He showed two rather nice lattice simulations showing a string-like structure stretched between a quark/anti-quark pair, and a Y-shaped triad holding together three quarks in a baryon. Very pretty, and apparently rigorous!

I would be interested in hearing the points of view of professional lattice gauge physicists about theses things - how successful are your calculations at present, and where are the main problems (I'm sure there must be some!).

Or, should we really start trusting lattice values for meson decay constants already?

Georg said...


The canonical reference for confronting Lattice QCD simulation results with experiment is hep-lat/0304004, which shows how the inclusion of dynamical quarks (the so-called "unquenching") improves the accuracy of lattice results to the point of being able to confront experiment at the one-percent error level.

A recent example of true predictions (rather than postdictions) is given in hep-lat/0509169.

Michael said...

Hi Georg, thanks for the references. The papers were quite interesting, and I posted a brief comment on Collider Blog about them.

Johan said...

I have understood that there are certain unresolved mathematical issues with LQCD. Could you explain in simple terms what they are?
I seems that they have to do with the continiuum limit. Is it mathematical unproven that a continiuum limit exists or is it just unproven that the limit has all the properties physicists want it to have?