Most newspaper reports of the recent discovery of a new fundamental boson (let’s agree to call it the Higgs, shall we?) mentioned the long time delay between Higgs postulating the particle and physicists detecting it. That got me to wondering, this morning, whether the time delay was particularly long.
Peter Higgs was the first to postulate the existence of a fundamental scalar particle that might be detectable. He did this in 1964. (Several physicists, at around the same time, argued that a fundamental scalar field was required to give other particles mass; you can read all about that elsewhere.) The point is, it took experimental physicists until 2012 – that’s 48 years – to find the particle and prove that it existed. Is 48 years a long time in this context?
Well, Wolfgang Pauli postulated the existence of the electron neutrino in 1930; it took until 1956 before it was discovered – a lag of 26 years between theory and experiment. There was a similar gap of about a quarter of a century between theorists postulating the existence of the top neutrino and experimenters finding it. (The muon neutrino was discovered a mere 14 years after it was postulated.) So it seems that neutrinos, which are notoriously difficult to study, were found much more quickly than the Higgs.
What about quarks? Well, the bottom and top quarks were postulated in 1973 by Kobayashi and Maskawa; the b quark was found in 1977 (a mere four year later) and the t quark was found in 1995 (a gap of 22 years). So the quark sector was cleared up fairly quickly too.
The W and Z bosons turned up in experiments in 1983, 15 years after Glashow, Salam and Weinberg told people to expect them.
So it would seem that the Higgs is indeed something of a standout amongst the elementary particles: it took almost twice as long to find the Higgs as it did to find any of the other fundamental particles that theorists posited. Personally I’m hoping that the LHC will turn up evidence for a supersymmetric particle. Although supersymmetry itself has a long history, going back to the 1970s, the first realistic supersymmetric version of the Standard Model didn’t arrive until 1981, with work by Georgi and Dimopoulos. If we take 1981 as the starting date, then, it won’t be until 2029 that the Higgs record for a delay between postulation and experiment is broken.