A little late, but I didn’t want to let slip this interesting discussion about the agonizing process of making experimental particle physics results ready for public consumption from Tommaso Dorigo and Gordon Watts. You’ll recall that we mentioned a couple of weeks ago the new results from Fermilab’s Tevatron on B-mixing, a measurement that puts interesting new constraints on the possibilities for physics beyond the Standard Model. The first announcement was from the D0 (“D-Zero”) experiment; as Collin pointed out in the comments, the CDF experiment followed with their own results soon thereafter.
From the CDF point of view, this is not how things are supposed to be; CDF is supposed to get there first, and D0 is supposed to confirm their results. Speaking from the CDF side, Tommaso talks about the process:
The publication process of CDF data analyses is baroque, bordering the grotesque. Once a group finalizes their result and presents it at internal meetings, the result has to be blessed. This involves three rounds of scrutiny, the full documentation of the analysis in internal notes, and often the fight with skeptics who like to sit at meetings and play “shoot the sitting duck” with the unfortunate colleague presenting the result. Usually, when an important result is on, the physicists who produced it are asked to perform additional checks of various kinds, and defend it with internal referees. When all of that is through, and not a day earlier, the result can be shown at Physics conferences.
After that happens, one would like to get the result on a Physics journal as soon as possible – to be cited!!! But just then, another much longer nightmare starts, when a process called “godparenting” begins and three knowledgeable colleagues (the godparents) are designated to scrutinize every detail of the work. Then a draft paper is produced, and in the following two weeks all the collaborators can play “shoot the duck” in written form, by sending criticism and demanding yet more checks. Then a second draft follows, and the process repeats…. In the end, usually six months pass between the blessing of a result at the physics meeting and the forwarding of a paper to a journal.
Gordon, from the D0 side, agrees with the general outline.
I don’t think it is that much different than what CDF has to go through — perhaps a bit more streamlined. We are all afraid that something wrong will make it out; hence all the layers of cross checking that go on. All of the collaboration is on the author list; this is the way the collaboration makes sure that the results that get out are correct. It can be a pain!
Read the whole things.
Of course there’s a lot more to the sociology of particle physics experiments than deciding when to release results. Interestingly, there are a lot of great books that take high-energy experiments and experimenters as their source material. Even novels — I recently read A Hole in Texas by Herman Wouk (best known for The Caine Mutiny and The Winds of War). It’s a short book set in the aftermath of the cancellation of the Superconducting Super Collider, imagining the hysteria if China managed to beat us to the Higgs boson. As a novel, I’ve read better; the romantic and political plots are somewhat perfunctory and not very believable. (And obviously written by a man; where else can you find no fewer than three attractive and accomplished women throwing themselves at a somewhat over-the-hill and not especially charming male physicist?) But the physics is surprisingly good; Wouk really put some effort into getting it right, including field trips to Fermilab and the SSC site.
And then you have your honest social-science explorations of the anthropology of the tribe of particle physicists. Beamtimes and Lifetimes, by anthropologist Sharon Traweek, treats HEP experimenters the same way we would treat an isolated tribe in the Amazon jungle, trying to figure out what makes them tick. (I’m still not sure.) But for my money, far and away the most insightful book is Nobel Dreams by Gary Taubes, the story of how Carlo Rubbia smashed the competition, not always using the most fair-minded tactics, to discover the W boson and win the Nobel Prize. Oh yes, and how he then failed to win another Nobel for discovering supersymmetry, despite repeatedly suggesting that his UA1 experiment had found evidence for it. A fascinating read, one that makes you tremble at the ambition of Rubbia and his lieutenants, admire the superhuman dedication of the many physicists on the project, and thank your lucky stars that your own working hours are a bit more sensible.
Update: Tommaso and Gordon explain more about the physics of the result.
