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Tommaso DorigoRSS Feed of this column.

Tommaso Dorigo is an experimental particle physicist, who works for the INFN at the University of Padova, and collaborates with the CMS and the SWGO experiments. He is the president of the Read More »

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Some unforeseen Christmas-vigil blog activity bringing here a few visitors more than average was traced today back to BBC News, who discussed the 2010 science highlights here.

The incoming link is in this paragraph:

The evolving role of the blogosphere in science came to the fore as particle physicists were preparing to gather in Paris for their annual conference. Internet rumours suggested that the US Tevatron particle smasher had seen hints of the elusive Higgs boson.

A reader of this blog asked in the comments thread of a recent piece the following interesting question:

"Assuming mH = 201 GeV/c2, how many Higgses shoud have been produced at
the Tevatron by now with an integated luminosity of 10 inverse
femtobarns? And how many H -> ZZ -> µµµµ would one expect to see?"
As sure as death and taxes, and as timely as a Swiss watch, the Tevatron collider never ceases to awe us. Well into its twentysixth year of life, the aged and celebrated proton-antiproton collider sitting just a few meters underground in the west Chicago suburbs hit the mark of 10 inverse femtobarns of collisions delivered to the core of the CDF and DZERO detectors.

10 inverse femtobarns! Ten inverse femtobarns of proton-antiproton collisions is a HELL of a lot of them. Plus, you should multiply that number by two, since the same number of collisions happened inside two different collision areas -those manned by the two competing collaborations.
An expert is a man who has made all of the mistakes which can be made, in a narrow field.
Niels Bohr
A faithful reader of this blog has been asking me for answers to some of the 42 questions which were given at an exam for particle physics researcher wannabes in Italy in 2005. I already provided some answers in a separate post a few months back, but the reader asked for an answer to some specific exercises which I had not bothered to deal with here. I will do so now.
A new result for the production cross section of Z boson pairs in proton-antiproton collisions at the 2-TeV Tevatron collider is now public, thanks to the efforts of the CDF collaboration. The measurement, in a nutshell, confirms Standard Model predictions nicely: the cross section is determined to be 1.45 picobarns, with an asymmetric error bar of of +0.60-0.51. The Standard Model, on the other hand, predicts that the cross section is 1.21 picobarns. The agreement of the two numbers, within uncertainties, says that all is well in the searched final state, and no unforeseen effects are at work.