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Unblinding the most precise W mass measurement today December 14, 2006

Posted by dorigo in news, physics, science.

Today, at 3.30PM Chicago time, CDF will make public its measurement of the W boson mass, which has a total uncertainty of 48 MeV (a 0.06% of the value) and is therefore the most precise single determination of this fundamental parameter of the standard model. I will post the number here as soon as it is broadcast. Stay tuned!

As for the significance of a low or high measurement with respect to the current world average (80392+-29 MeV), I will speak about it in the next post, where I intend to answer a long list of questions by a reader who left a comment in https://dorigo.wordpress.com/2006/12/13/more-speculations-on-non-175-gev-single-top-from-d0-data/ .

For the time being, suffices to say that the probability that the CDF result is lower than the world average is 155/200, since the preliminary (blind) measurement is 80336 MeV with a blind offset of +-100 MeV, and the blind offset has of course a flat probability distribution, 155/200 of which lies below 80392 MeV.  


1. Bo - December 14, 2006

Tommaso– be careful with proclamations about the number being public today; it still has to be blessed after the unblinding😉

2. dorigo - December 15, 2006

Hi Bo,

in fact, I gather the result is only pre-blessed. Too bad… We’ll wait one more week. So be it!


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