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Accelerating Dark Matter Searches With Machine Learning

I am currently spending the week in Leiden (Netherlands), attending to a very interesting workshop...

On The Qualifications Of Peer Reviewers For Scientific Papers

Peer review is the backbone of high quality scientific publications. Although the idea that only...


The title of this post is the password code required to connect to my wireless network at home...

Venice --> Padova

I was born and have lived in Venice for over 51 years now (omitting to mention some 2 years of...

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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 »

In the last few days I described in some detail (here and here) the six searches for the Standard Model Higgs boson just produced by CMS, the experiment at the CERN Large Hadron Collider to which I proudly belong.
In my short summary of analyses recently published by CMS, yesterday I left out one which had not yet been released. It is the search for the "golden channel" of Higgs decay, the one which motivated the construction of detectors with large acceptance to energetic leptons: the decay to two Z bosons, with a subsequent decay of the Z's to two charged leptons each.
An orgy of new results has started. Let me just show a few of them concerning Higgs searches in CMS - I am on vacation after all, and I have little time left to comment these interesting new papers and plots after all the sunbathing and restaurants.

Let us start with the Higgs search in the diphoton decay mode by CMS (paper here). With 1.09 inverse femtobarns of data, CMS has a pretty good reach even to this very rare decay mode of the Higgs boson. Let me remind you that only a handful every thousand Higgs particles decay into two photons, in the most favourable circumstances.
Impressive. If you had been seeking for top quarks in 4-inverse-picobarns datasets since 1992 as I have, and then rejoiced at the 7-event signal from which CDF extracted in 1994 mass and cross section of the long-sought sixth quark, you would now also be looking for adjectives upon having a look at the figures in the new CMS paper, which uses over one inverse femtobarn of proton-proton collisions to measure the tiny asymmetric kinematics of top quark pairs produced at the LHC.
This afternoon (2.30 PM Chicago time) Pat Lukens, an old-timer of the CDF experiment, will give a "wine and cheese" seminar at Fermilab on the new observation of a heavy baryon, of the family of baryons containing bottom quarks, which was still at large.

The new particle, called "Xi_b^0", fits a hole in the group representation graph of ground-state baryons with J=1/2. You can see it in the graph on the right. Of all states in the middle level (ones containing one bottom quark) only the Xi_b^0 was still missing. By the way: none of the baryons of the top level have yet been observed.
Today I casually ran into a very nice figure which is perfect for an entry as "guess the plot", both because of its mysterious appearance, and because of the interesting physics it hides. It is a two-dimensional "surface" and its shape should tell you something. For the moment, I will just say it is something which has to do with both particle physics and astrophysics, and that it is quite cool, being a new way of looking at something we know well.