A Quantum Diaries Survivor

The following is an excerpt from a book I am working on intermittently. I do not know whether the project will ever see the light, and it just occurred to me that I could share a tiny bit of it with you in my blog. Enjoy!----

A process which caught some of the LHC Higgs analysts by surprise in the recent run of analyses for summer 2011 conferences is the production of multiple-lepton events by a process called "internal photon conversion in Z events". What is it, and how can we size it up ?

The conversion of a real, energetic photon into a fermion-antifermion
pair readily occurs when the particle traverses a medium: the process is also known as "pair production", and is the leading form of energy loss of energetic photons in matter. It is thanks to it (and to the related process called "bremsstrahlung" of energetic electrons) that our electromagnetic calorimeters can measure electrons and photons!

This morning I read with interest a paper on Physics Today, titled "Communicating the Science of Climate Change", by R. Somerville and S. Hassol. In it, there is a table worth pondering about. Here it is:

October is passing and the neutrino saga continues to make headlines here and there, but I know that the excitement is bound to slowly dampen, as the preprint claiming superluminal speeds ages in the Arxiv without being sent to a scientific magazine.

The saga of the superluminal neutrinos took a dramatic turn today, with the publication of a very simple yet definitive study by ICARUS, another neutrino experiment at the Gran Sasso Laboratories, who has looked at the neutrinos shot from CERN since 2010.

The saga of the superluminal neutrinos took a dramatic turn today, with the publication of a very simple yet definitive study by ICARUS, another neutrino experiment at the Gran Sasso Laboratories, who has looked at the neutrinos shot from CERN since 2010.

Higgs boson hunters often catch themselves dreaming of the boson having a mass high enough to give rise to the spectacular decay into two Z bosons, and then four charged leptons in the final state. At a hadron collider -let's talk of the LHC to be specific- such a signature is the only one providing events which, once properly selected, are more likely signal than background. The situation of observing an event display being able to tell for sure what it represents, among the infinite possibilities and the intrinsic indetermination of quantum processes, is reassuring and gives a physicist a feeling of power. God did not play dice this time: those two are 100% Z bosons, and their combined mass is exactly the one of the Higgs.

I read with interest and some amusement (on the mouse joke) the piece written here by Sascha Vongehr. I find his arguments wrong and decided to answer him in the comments thread of his post, but my answer got a bit too long and I did not want to hijack a nice discussion that was developing there; plus I found out that what I was writing could be suitable for this blog in its own right. So below I explain what I criticize about his arguments.

Fabrizio Tamburini (left) is an old friend - I have known him since 1976, when we both used to attend the gatherings of the newborn Associazione Astrofili Veneziani, at the Lido of Venice. The love for astronomy had brought us together, but we took different paths in our scientific activities. Fabrizio remained maybe more faithful to his old love for the universe, and is now a well-known and respected astrophysicist, who studies original ideas in the physics of photon propagation and more. I repeatedly invited him to write about his research here, but so far he has not accepted, mainly for lack of time... But I am sure he will soon.

The Draconids (also called Giacobinids) are a meteor shower associated to comet Giacobini-Zinner (see below for a 100-year-old picture of the comet). While most years this shower passes unnoticed to all but few professionals and experts amateurs, yielding only very few meteors in the nights between October 6th and 10th, every once in a while the Draconids do put up a real show, producing hundreds, or even thousands of meteor streaks per hour in clear skies.

One of the issues that emerged in the discussion of whether researchers should be bloggers is the fact that it is always dangerous to wear multiple "hats", i.e. carrying multiple responsibilities which may sometimes come in conflict with one another.Wearing two hatsOf course this is a very common and old problem. I am indebted to Jim S.M., who sent me a few excerpts from Churchill's autobiography, which are very relevant to the issue besides being quite amusing:

Tomorrow I will fly to Frascati, where are the headquarters of INFN, the italian institute for nuclear physics. I will attend to an event there, called "Incontri di Fisica" (Physics meetings), where high-school teachers meet researchers and receive training, as well as discuss ways to improve science education and popularization in schools and outside.I will be discussing the subject of "Science popularization with blogs" on Wednesday afternoon and then, two days later, I will be the last speaker with another short talk, where I will try to summarize some ideas on the matter. And you might help for this latter presentation.