View Single Post
Feb12-12, 07:00 AM
P: 93
The QCD vacuum condensate which breaks chiral symmetry in qcd, also break the SU(2) electoweak gauge symmtery, right?
The operator which gets a vacuum expectation value isn't SU(2) invariant since it is built out of left handed quarks and right handed quarks which are in different representations of SU(2).
This should contribute about ~100MeV the W and Z masses. Why is this never taken into account in EWPT? because the condensate should be the same for up and down type quarks, I would think it woudn't contibute to the T parameter (isospin symmetry), But it should contribute to the S parameter.
Is this simply negligible, or I've got it all wrong?
Phys.Org News Partner Physics news on
Physical constant is constant even in strong gravitational fields
Physicists provide new insights into the world of quantum materials
Nuclear spins control current in plastic LED: Step toward quantum computing, spintronic memory, better displays