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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 »

Today the Cornell arxiv features a paper by J. Aguilar Saavedra and F. Jouaquim, titled "A closer look at the possible CMS signal of a new gauge boson". As I read the title I initially felt somewhat lost, as being a CMS member I usually know about the possible new physics signals that my experiment produces, and the fact that we had a possible signal of a new gauge boson had entirely escaped my attention. Hence I downloaded the paper and started reading it, hoping to discover I had discovered something new.
As I reported a couple of times in the course of the last three months, the ATLAS experiment (one of the two all-purpose experiments at the CERN Large Hadron Collider) has launched a challenge to data analyzers around the world. The task is to correctly classify as many Higgs boson decays to tau lepton pairs as possible, separating them from all competing backgrounds. Those of you who are not familiar with the search of the Higgs boson may wonder what the above means, so here is a crash course on that topic.

Crash course on the Higgs and its decays to tau leptons
Everybody seems to be talking about the Kardashian index (call it K) these days. It is a rather useless number that you compute as a ratio between the number of twitter followers you have and the number of citations that your papers got.

Here is a quote from its inventor Neil Hall:

“I am concerned that phenomena similar to that of Kim Kardashian may also exist in the scientific community,” wrote Hall. “I think it is possible that there are individuals who are famous for being famous (or, to put it in science jargon, renowned for being renowned). We are all aware that certain people are seemingly invited as keynote speakers, not because of their contributions to the published literature but because of who they are.”
The other day I wrote a post reporting of the lowered expectations of SUSY enthusiasts, who now apparently look forward to seeing 2-sigma effects in the next Run data of the CMS and ATLAS collaborations. That would keep their hope going, apparently.

I would have no problem letting them wait for late 2015, when the first inverse femtobarns of 13 TeV collisions will have been given a look at. But another thing happened today which made me change my mind - a colleague noted in the comments thread of that article that the LHC experiments appear to not publish their 2- and 3-sigma excesses when they see them, waiting for more data that "wipes out" the fluctuation. This is a strong (and probably unsupported) claim!
This morning at the ICNFP 2014 conference in Kolympari (Crete) the floor was taken by Abdelhak Djouadi, who gave a very nice overview of the theoretical implications of the Higgs boson discovery, especially exploring the status of Supersymmetry models.

Djouadi explained how even if the average mass of sparticles is being pushed up in surviving models of Supersymmetry -both because of the negative result of direct searches and because of the effect of hardwiring in the theoretical models the knowledge of a "heavy" lightest scalar particle, which sits at 125 GeV- there is reason to be optimistic. He explained that for stop quarks, it is the geometric mean of their masses that has to be high, but the lightest one may be laying well below the TeV.

Yesterday I gave a lecture at the 3rd International Conference on New Frontiers in Physics, which is going on in kolympari (Crete). I spoke critically about the five-sigma criterion that is nowadays the accepted standard in particle physics and astrophysics for discovery claims.

My slides, as usual, are quite heavily written, which is a nuisance if you are sitting at the conference trying to follow my speech, but it becomes an asset if you are reading them by yourself post-mortem. You can find them here (pdf) and here (ppt) .