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No Light Dark Matter In ATLAS Search

Yesterday the ATLAS collaboration published the results of a new search for dark matter particles...

Cold Fusion: A Better Study On The Infamous E-Cat

Do you remember the E-Cat ? That is an acronym for "energy catalyzer", the device invented by the...

The Quote Of The Week - A Between-The-Lines Accusation Of Scientific Fraud

"Fermilab has very actively tried to scoop us by press release, even though their uncertainties...

Can You Find This San Francisco Chronicle Article For Me ?

At the workshop I attended last week ("Publish, blog, tweet - furthering one's career in science")...

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Tommaso DorigoRSS Feed of this column.

I am an experimental particle physicist working with the CMS experiment at CERN. In my spare time I play chess, abuse the piano, and aim my dobson telescope at faint galaxies.... Read More »

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I came to know through a social network (I have many colleagues as friends there, and they usually post more useful stuff than cute kittens) that ATLAS has launched a very intriguing competition. One you can participate to, if you have some programming skills; no knowledge of particle physics is needed.

The idea is to ask you to classify as signal (Higgs decay to tau lepton pairs, if you really want to know!) or background (anything that looks similar to it but involves no Higgs boson) a set of 550,000 events, for each of which ATLAS gives you 30 kinematical quantities measured in the detector (it is a simulation, but it's a pretty good approximation of reality).
Very recently, a combination of the precise measurements of the mass of the top quark obtained by the CDF and DZERO experiments at the Fermilab Tevatron collider with those produced by the ATLAS and CMS experiments at the CERN LHC collider has been produced, obtaining a result of 173.34 GeV, which surprised nobody -of course- with a very small total error bar: 0.76 GeV, a mere 760 MeV, not even a proton's mass.
"In the case where the dark matter particle is light (less than 1 GeV) and the interactions is either contact or mediated by light (but not massless) particles, there is parameter phase space that cannot be probed by current underground detectors even with substantially lowered energy thresholds. This region of the parameter space can be probed by shallow site detectors with low energy thresholds. However, since in this case dark matter particles will be very effectively stopped if coming upwards (i.e. below the detector), we argue that a search for a daily modulated dark matter signal is probably the best strategy for probing this part of the parameter space."
This must be the boosted b-jets season... Just a few days ago I discussed here the nice new observation of boosted Z->bb decays pulled off by the ATLAS collaboration using 8-TeV proton-proton collisions recorded in 2012. And today I am pleased to see in the Arxiv a new study by D. Ferreira de Lima, A. Papaefstathiou, and M. Spannowsky on the possibility to measure the pair production of Higgs bosons in their decay to two pairs of b-quark jets.
I was delighted today, as I checked the page of public ATLAS results, to find a very beautiful new result. The signal ATLAS found and just published on the arxiv is not one anybody could doubt to be there: no surprise whatsoever. And yet, it is a difficult one to extract, and one on which I myself have spent several years of my research work on the CDF experiment.
The 35th international chess tournament in Mogliano Veneto this year did not feature strong grandmasters or international masters, but a pack of 24 local players of average strength around 2150. Still, it was a very hard-fought competition, with almost no game ending as a draw before all winning attempts had been tried.

I scored a rather disappointing 2 points out of 5, losing two games -one of them undeservedly, for a performance rating is 2030, a bit less than what I believe is my current playing strength. Below I report my only win, against Enrico Danieli, an elo 2070 player.

Danieli-Dorigo, Mogliano 2014
1.d4 d5 2.Nc3 Bf5 3.e4?!