Has the mass of the common quark been nailed down?

ScienceNOW : It’s not every day that scientists reduce the uncertainty in a fundamental constant of nature from 30% to 1.5%, but a team of theoretical physicists claims to have done just that.Using supercomputers and mind-bogglingly complex simulations, the researchers have calculated the masses of particles called “up quarks” and “down quarks” that make up protons and neutrons with 20 times greater precision than the previous standard.The new numbers could be a boon to theorists trying to decipher particle collisions at atom smashers like Europe’s Large Hadron Collider (LHC) or trying to develop deeper theories of the structure of matter."It’s an audacious claim, and it will have to be looked at very carefully, but I think the result is robust,” says Paul Mackenzie, a theorist at Fermi National Accelerator Laboratory in Batavia, Illinois, who was not involved in the work.