Yesterday we at Northwestern enjoyed a site visit by the DOE. The point of a site visit is to allow the DOE representative to assess, first hand, what the researchers are actually doing. Many senior physicists in HEP can write wonderful prose extolling the achievements of their groups, but a face-to-face meeting stretching over several hours allows the DOE representative to probe and check.
Anyway, one of the pleasures of the site visit is hearing what other researchers in your own institution have accomplished. There was one very brief presentation concerning the D0 experiment at the Tevatron, during which the speaker trotted out some of the nicest D0 results in electroweak and top physics. Since I am working hard in electroweak physics in CMS, and used to work in electroweak physics in CDF, I tend to view such presentations with a very critical eye. But indeed, setting aside any quibbles about systematic uncertainties and acceptance corrections, the achievements of the D0 Collaboration – and of the CDF Collaboration – are astounding considering the starting point back in the 1980s when I was still a graduate student. As Ken Bloom nicely explained, the physics results produced by D0 and CDF over a decade of 2 TeV running are far beyond anyone’s expectations, back in the 1980s. For example, the possibility of measuring of the top quark with an error better than 1.5 GeV was ridiculed at the start of Run II – yet look how well the Tevatron experiments have done and how important this result is for particle physics. Look at the measurement of the W mass, of Bs mixing and heavy flavor spectroscopy, of a wide range of QCD tests and studies of weak boson production, etc. etc. These results are like stars in the constellation of collider physics.
Two or three generations of Tevatron experimenters achieved what no one would have expected – projections for such measurements would have been considered pipe dreams, pie in the sky, or fantasy. Yet they did it, providing an excellent starting point for the LHC.
During the dinner that concludes the DOE site visit, we discussed prospects for measuring longitudinal WW scattering, which is intimately related to the existence and properties of a Higgs boson. The common wisdom is that it is very difficult and perhaps impossible to measure the cross section accurately. However, one or the theorists argued that, given time and data, experimenters always achieve more than one ever expects. I think he is right – and the record of the Tevatron proves it.