I won’t bother to write up something about the background of today’s MiniBooNE results, since Tommaso Dorigo has already done a better job than I ever could. He also provides a link to where the live feed of the seminar will be, starting at 11am CDT. I’ll be in class at that time, but an hour later will try and attend the local seminar here at Columbia featuring Mike Shaevitz discussing the results.
And the result is….
No mu-neutrino to electron-neutrino oscillations of the sort that would explain the LSND result and require an extension of the Standard Model (beyond giving masses to the 3 known neutrinos). MiniBooNE was designed specifically to look for this, and has successfully ruled it out at 98% confidence level. They do see something anomalous in their data at low energy, but it is not compatible with being due to the kind of neutrino oscillations they were looking for. It’s also true that they just first got a look at this data two weeks ago, still have a lot of work to do to see if there is some sort of background contamination they hadn’t expected at these energies, or something they didn’t know about low energy cross-sections. Maybe it will take them a while to sort this out, but the bottom line is that what they were looking for is definitely not there.
Press release here, paper to come soon.
Update: For an excellent description of the result from Heather Ray, one of the MiniBooNE experimenters, see this guest posting at Cosmic Variance.
Warning: serious people should stop reading now, the rest is a low form of entertainment.
For something truly hilarious, you really should be following Lubos’s continually evolving misunderstandings of this experimental result, which he has taken as a reason for launching into another bizarre rant about me and Lee Smolin. As near as I can figure out, Lee and I are responsible for the misguided idea of designing an experiment like MiniBooNE to check into the possibility that LSND was seeing evidence of a sterile neutrino. His posting keeps changing (its URL is miniboone-confirms-lsnd, title now “Miniboone Refutes LSND”), with the early versions saying:
Evidence for several types of neutrino oscillations have been known for a decade or more. That includes atmospheric neutrino oscillations, solar neutrino oscillations, and a lab experiment called LSND in Los Alamos.
A simple oscillation in between two neutrino flavors – electron neutrino and muon neutrino – was a natural candidate to explain the observations but it couldn’t explain details of the LSND data which is why the LSND results were questioned. Another natural candidate was a two-flavor oscillation that includes a sterile neutrino, a new kind of neutrino without a charged partner.
Today, Fermilab’s MiniBooNE experiment has confirmed that the LSND results were correct and a more subtle explanation than the simple two-flavor oscillation is necessary. The result rules out the possibility that the observed oscillation is a two-flavor oscillation involving a new sterile neutrino. Their results indicate that there is something surprising that doesn’t fit the most obvious model.
He does seem to have more recently gotten a clue about this and noticed that it doesn’t confirm the LSND results, editing his posting and adding the standard obsessive rant. I see that in his previous posting (about a Harvard faculty meeting), according to him the proposed new Harvard core curriculum states that “All of science education must lead to increasing food production for the working class in the next 5 years [added to please Peter Woit]”.
It seems that I am not only determining the course of neutrino experiments, but also setting the Harvard core curriculum. My powers are truly immense…
Update: Lubos has now changed the file-name from “miniboone-confirms-lsnd.html” to miniboone-refutes-lsnd.html, and deleted the comments from people explaining to him that he was confused. The new version starts off with:
I have erased several comments that only increased the amount of confusion, changed the filename to break links from crackpots’ blogs, and hope that the text below is now more or less OK.