Can someone provide an expanded explanation on the statement that the Higgs field is already 3/4 detected?
Link to ref (@nic, sorry I left it off, do a quick search on Higgs to find the right location on page)
The link you provided is a page of G t'Gooft on an official site and is quite interesting reading.
the statement you are wondering about is:
He is stating that the Higgs' existence is based on the very strong verification of the Standard Model. There is strong experimental verification of the existence of W+ W- and Z The construction of the theory is such that since the gauge bosons exist one has 3/4 of the data needed to confirm the model, of which the existence of the Higgs is 1/4, counting up dimensions, of the necessary evidence/prediction. He is equating the existence of the Higgs to the validity of the SM in this statement.
The Higgs field in the Standard Model is a scalar field that is a complex $SU(2)$ doublet, so it has 4 real scalar degrees of freedom. Electroweak symmetry breaking converts 3 of these 4 scalar degrees of freedom into longitudinal modes of 3 gauge bosons, which then become massive. These 3 massive gauge bosons all have been observed in collider experiments at CERN ($W^\pm$, $Z$ bosons). So we know for sure that they exist. The fourth degree of freedom - the Higgs particle - has not been observed.
In this sense it is true that 3/4 of the Higgs field have been observed, but it is not true that 3/4 of the Higgs particle have been observed, since the latter is precisely the missing quarter.
This statement reminds me a bit about a joke on the "early evidence for supersymmetry": nearly half of the particles of the minimal supersymmetric Standard Model have been observed already ;-)
Update after July 4th 2012: now all 4/4 are discovered - congrats to CMS and ATLAS!