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Acknowledged

It is nice when somebody publishes an article and acknowledges your contribution, even when the...

Revenge Of The Slimeballs: When US Labs Competed For Leadership In HEP

The clip below, together with the following few which will be published every few days in the coming...

Muon G-2: The Anomaly That Could Change Physics, And A New Exciting Theoretical Development

Do you remember the infamous "g-2" measurement ? The anomalous magnetic moment of the muon has...

600 Attend To Outreach Event In Venice

On Saturday, July 8th, the "Sala Perla" of the Palazzo del Casinò was crowded by 600 attendees...

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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 experiment at the CERN LHC. He coordinates the European network... Read More »

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The figure for you to guess which I posted two days ago is built with simulated events featuring the production, at the Tevatron collider, of a Z boson (decaying to electron-positron or muon-antimuon pairs) together with an energetic photon. Apart from Tulpoeid, who of course knew this since Z-gamma production was her PhD thesis topic, only one other reader posted here a solution close to the correct one.
The Upsilon suppression paper by CMS is now public, and you can find it here. I decided to put an entry here since several people asked me to access the information...

Note that this paper is a quite important publication, which not only deals with Y suppression, but more in general with a quantification of dimuon resonance yields. Happy reading!



While the LHC runs like a swiss train and collects dozens of inverse picobarns a day, there's a celebration going on on the other side of the Atlantic, as this picture testifies:



The folks pictured here at the Fermilab village have a reason to cheer up: the glorious Tevatron has just delivered 11 inverse femtobarns of proton-antiproton collisions to CDF and DZERO. What a huge achievement that has been!
Upon being reminded by an automated messaging system, somewhat disturbingly, that today would be the birthday of an esteemed colleague -were he not dead- I decided to post a "guess the plot" entry which pays him a tribute.

The figure below is for you to guess (ignore the blue box at the lower right -it just hides some giveaway information). What does it represent ? What is in the abscissa ? And on the y axis ? Why do the data only populate the upper left half ? And what causes those two funny concentrations ?
Please try your luck and make your guess in the comments thread! It's fun, it's free, it makes me happy to see you considered the riddle, and it adds interest to this column!
A few months ago LHC took a special run of proton-proton collisions at  2.76 TeV. Why the lower energy, now that we are accustomed to searching for new phenomena at the highest available energy of 7 TeV ? Because of the wish to compare lead-lead collisions, taken last year at 2.76 TeV nucleon-nucleon energy, with proton-proton ones. The comparison allows to extract extremely interesting results.
Just a short post to mention that the Large Hadron Collider has reached tonight the top instantaneous luminosity of 1.075 * 10^33 cm^-2 s^-1. This is a new record for high-energy hadron colliders, improving over precedent records already set this year by the CERN machine. The peak luminosity is 2.5 times larger than the highest reached at the Tevatron (which, one needs to remember, collides protons against antiprotons, and the difficulty in producing the latter makes the comparison between LHC and Tevatron luminosity a bit deceiving).