A Quantum Diaries Survivor

The 2009 World Conference on Science Journalism took place last week in heat-wave-struck London, at the convenient location of Westminster Central Hall (see below). More than 900 delegates got together from 90 countries to discuss the future of science journalism, understand the challenges the field is facing, and finding strategies to face them. An impressive event, excellently organized.

As I promised a week ago, I am posting answers to a few of the 42 questions which constituted the first part of an the exam selecting experimental particle physicists for the INFN (the italian institute of nuclear physics) four years ago. Next week, a similar exam will take place to "qualify" post-doctoral scientists which aspire at a temporary position with INFN.

In a few days, scores of Italian post-doctoral researchers in experimental particle physics will get tested on their knowledge of the matter, without any promise of a position, but just to get one further "stamp" on their curriculum, testifying that they are competent enough to be worth offering a temporary position by INFN, the Italian Institute for (sub)Nuclear Physics. So this is a  national exam, with the sole purpose of giving a green light to be admitted to two-year positions , which are typically paid less than 1400 euros a month, and which are so far not available. Frankly, I feel ashamed, since I myself work for INFN, and I strongly disagree with its current recruitment policies.

If you have followed this blog for long enough, dear readers, the words "multi-muons", "anomalous muons", or even "lepton jets" are not foreign to you. They all refer to a paper appeared on the ArXiv on the evening of Halloween last year. In the paper the CDF collaboration published the results of a detailed analysis which described how a component of collider data containing two or more muons could not be explained by known Standard Model processes.

In a few days italian post-docs working in high-energy physics will be asked to gather for a nasty exam, held by the INFN -the italian institute for nuclear physics- to qualify valiant researchers for future hiring in the institute.The exam generated a wave of outrage among the very pool of people at which it is aimed: the scores of "precari" (temporary workers) who are spending the best years of their life to try and make a career in particle physics.  Let me explain why that is so.

Prologue

Below I offer a preview of the slides I will show tomorrow at an invited seminar on the rather technical topic of  "The b-jet energy calibration with Z-->bb decays", which I have come to CERN to give at a meeting of the LHCb collaboration. As I mentioned already in the first part of this two-part article, the topic is rather technical, and I do not expect a large audience -but I will nonetheless make an attempt at explaining the meaning of the slides pasted below. Then, of course, I am available to provide some additional light on any specific issue among those dealt below which you may want to understand more about.

Tomorrow I am traveling to CERN, where I have been invited to give a seminar at a meeting of the LHCb experiment. My talk will discuss the issue of the energy calibration of b-quark jets, a topic to which I have devoted a good part of my research time for the last thirteen years. The talk will of course be centred on the explanation of the analysis Julien Donini and I, together with a few colleagues, performed in CDF a few years ago, the search for Z boson decays to b-quark jet pairs.

Today I visited the 53rd international art exposition at the Biennale di Venezia, which this year is titled "Fare Mondi" (making worlds). I am posting below a few pictures I took of the installations I saw there, for those of you who are not insensitive to contemporary arts. But before I do, let me add a personal note.

From 1958 to 1970 Wladimiro Dorigo, my father, directed a political and cultural magazine called "Questitalia" ("This italy"), where emerging political issues were discussed, and the ongoing transformations of Italian society were dissected by a distinguished group of intellectuals. I own a copy of all the 150 issues of that publication, and every once in a while I pick one of them out of the lot at random, and learn what Italy was 40 or 50 years ago.

It is a well-known fact that it is much easier to measure a physical quantity than to correctly assess the magnitude of the uncertainty on the measurement: the uncertainty is everything! A trivial demonstration of the above fact is the following. Consider you are measuring the mass of the top quark (why, I know you do it at least once a week, just to keep mentally fit). You could say you have no idea whatsoever of what the top mass is, but you are capable of guessing, and your best guess is that the top mass is  twice the mass of the W boson: after all, you have read somewhere that the top quark decays into a W boson plus other stuff, so a good first-order estimate is 2x80.4= 160.8 GeV.

It feels good, for a die-hard sceptic like I am, to live and let unexplained phenomena die. The phenomena in question are measured deviations from the predictions of the Standard Model (SM), our wonderful theory of subnuclear interactions, which has been condemned to fail by theorists soon after its construction, but continues, disappointingly for many, to succeed in explaining experimental results.