Experimenters at the Tevatron have released data showing the existence of a new baryon, built out of a down, strange and bottom quark, and having a mass of 5.774 +/- .019 GeV. It has been given the name “Ξb“. The FNAL press release is referring to this as a “triple-scoop” baryon, since it contains one quark from each of the three generations. Tommaso Dorigo has a new posting about this.
Postings on this blog tend to involve a certain amount of discussion of bad behavior by theorists, so I guess I should point out here that this story comes with some accusations of less than good behavior by experimentalists in the way this was announced. The press release is all about the announcement of this discovery by the D0 experiment, and about their paper, which was submitted to the arXiv Tuesday night. It turns out though that D0’s competition, CDF, also has had the same result for a while, and it had already been “blessed” but not officially announced. So CDF was “scooped” at the last moment for the “triple-scoop”, and I imagine there are dark accusations going around about how D0 might have found out about this and rushed out the paper and press release. Supposedly there is an informal one-week notification period that the two experiments normally observe to keep this kind of thing from happening. Anyway, looks like they’re trying to fix it up a bit: the FNAL web-site contains a “special announcement” of back-to-back seminars about this, D0 at 1pm, which will “immediately be followed” by a CDF seminar. The D0 seminar is called
First observation of a new b-baryon, Ξb
whereas the CDF seminar is entitled
Observation of a new b-baryon, Ξb