A Quantum Diaries Survivor

Trevor Hastie, the Stanford University guru on Statistical Learning (he coined the term together with his colleagues Tibshirani and Friedman) is in Padova this week, where he is giving a short course on his pet topic and a seminar. I am happy to report this as this was partly made possible by the European Union-funded network of which I am the project coordinator, AMVA4NewPhysics. But most of the merit is of Prof. Giovanna Menardi, PI of the Padova node of the network, who organized it... And of course I am happy because I am learning from his insightful lectures!(Above, prof. Menardi introduces the lectures).

At 10:00 AM this morning, my smartphone alerted me that in two months I will have to deliver a thorough review on the physics of boson pairs - a 50 page thing which does not yet even exist in the world of ideas. So I have better start planning carefully my time in the next 60 days, to find at least two clean weeks where I may cram in the required concentration. That will be the hard part!

The top quark is the heaviest known matter corpuscle we consider elementary. Elementary is an overloaded word in English, so I need to explain what it means in the context of subatomic particles. If we grab a dictionary we get several possibilities, like e.g.- elementary: pertaining to or dealing with elements, rudiments, or first principles- elementary: of the nature of an ultimate constituent; uncompounded- elementary: not decomposable into elements or other primary constituents- elementary: simple

In 1952 my uncle Antonio, then 18 years old, left his family home in Venice, Italy to never return, running away from the humiliation of a failure at school. With a friend he reached the border with France and crossed it during the night, chased by border patrols and wolves. Caught by the French police Toni - that was the abbreviated name with which was known by everybody - was offered a choice: be sent back to Italy, facing three months of jail, or enrol in the French legion. Afraid of the humiliation and the consequences, he tragically chose the latter.

Another chapter in the saga of the search for the elusive, but dominant, decay mode of the Higgs boson has been reported by the CMS collaboration last month. This is one of those specific sub-fields of research where a hard competition arises on the answer to a relatively minor scientific question. That the Higgs boson couples to b-quarks is indirectly already well demonstrated by a number of other measurements - its coupling to (third generation) quarks being demonstrated by its production rate, for example. Yet, being the first ones to "observe" the H->bb decay is a coveted goal.

Back from vacations, I think I need to report a few random things before I get back into physics blogging. So I'll peruse the science20 article category aptly called "Random Thoughts" for this one occasion.My summer vacations took place just after a week spent in Ecuador, where I gave 6 hours of lectures on LHC physics and statistics for data analysis to astrophysics PhD students. I did report about that and an eventful hike in the last post. Unfortunately, the first week of my alleged rest was mostly spent fixing a few documents that the European Commission expected to receive by August 31st. As a coordinator of a training network, I have indeed certain obligations that I cannot escape. 

If I am alive, I probably owe it to my current very good physical shape.That does not mean I narrowly escaped a certain death; rather, it means that if I had been slower there are good chances I would have got hit by lightning, under arduous conditions, at 4300 meters of altitude.

This is the fifth and final part of Chapter 3 of the book "Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab". (the beginning of the chapter was omitted since it described a different story). The chapter recounts the pioneering measurement of the Z mass by the CDF detector, and the competition with SLAC during the summer of 1989.  The title of the post is the same as the one of chapter 3, and it refers to the way some SLAC physicists called their Fermilab colleagues, whose hadron collider was to their eyes obviously inferior to the electron-positron linear collider.

This is the fourth part of Chapter 3 of the book "Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab". The chapter recounts the pioneering measurement of the Z mass by the CDF detector, and the competition with SLAC during the summer of 1989. The title of the post is the same as the one of chapter 3, and it refers to the way some SLAC physicists called their Fermilab colleagues, whose hadron collider was to their eyes obviously inferior to the electron-positron linear collider.

This is the third part of Chapter 3 of the book "Anomaly! Collider Physics and the Quest for New Phenomena at Fermilab". The chapter recounts the pioneering measurement of the Z mass by the CDF detector, and the competition with SLAC during the summer of 1989. The title of the post is the same as the one of chapter 3, and it refers to the way some SLAC physicists called their Fermilab colleagues, whose hadron collider was to their eyes obviously inferior to the electron-positron linear collider.

I have recently been reproached, by colleagues who are members of the competing ATLAS experiment, of misusing the word "see" in this blog, in the context of searches for physics signals. That was because I reported that CMS recently produced a very nice result where we measure the rate of H->bb decays in events where the Higgs boson recoils against a energetic jet; that signal is not statistically significant, so they could argue that CMS did not "see" anything, as I wrote in the blog title. 

A new analysis by the ATLAS collaboration, based of the data collected in 13 TeV proton-proton collisions delivered by the LHC in 2016, finds an excess of X-->4 lepton events at a mass of 240 GeV, with a local significance of 3.6 standard deviations. The search, which targeted objects of similar phenomenology to the 125 GeV Higgs boson discovered in 2012, is published in ATLAS CONF-2017-058. Besides the 240 GeV excess, another one at 700 GeV is found, with the same statistical significance.