A Quantum Diaries Survivor

This is just a short post to report about a useful paper I found by preparing for a talk I will be giving next week at the 3rd International Conference on New Frontiers in Physics, in the pleasant setting of the Orthodox Academy of Crete, near Kolympari.My talk will be titled "Extraordinary Claims: the 0.000029% Solution", making reference to the 5-sigma "discovery threshold" that has become a well-known standard for reporting the observation of new effects or particles in high-energy physics and astrophysics.

Many new particles and other new physics signals claimed in the last twenty years were later proven to be spurious effects, due to background fluctuations or unknown sources of systematic error. The list is long, unfortunately - and longer than the list of particles and effects that were confirmed to be true by subsequent more detailed or more statistically-rich analysis.

A timely article discussing the hot topic of the production rate of pairs of vector bosons in proton-proton collisions has appeared on the Cornell arxiv yesterday. As you might know, both the ATLAS and CMS collaborations, who study the 8-TeV (and soon 13-TeV) proton-proton collisions delivered by the Large Hadron Collider at CERN, have recently reported an excess of events with two W bosons. The matter is discussed in a recent article here.

In the process of revising a chapter of my book, I found a clip I would like to share here, as it contains an analogy I cooked up and which I find nice enough to be proud of. Well, two analogies, as you'll soon find out; here I am speaking of the cat weighing trouble at the end of the piece - the other is quite trivial. The topic is the widely different masses of fermions, the building blocks of our universe, and the trouble in making sense of it and of measuring precisely their values. Comments welcome!

Two years have passed since the discovery of the Higgs boson (on July 4th, 2012), and the young particle still causes excitement. Originally it was the excess of Higgs decays to photon pairs as seen by the ATLAS experiment - but that anomaly has vanished with more data and more careful analyses. Then, it was the turn of the twin peaks: ATLAS again saw an inconsistent mass measurement with photon pairs and Z boson pairs.

Among the many more-or-less boring news from the ICHEP conference (International Conference on High Energy Physics), which is presently going on in Valencia (Spain), one bit today is sending good vibrations through the spine of many of the few phenomenologists who have chosen to remain faithful to the idea of Supersymmetry all the way to the bitter end. It is the excess of diboson events that ATLAS has just reported there.

A couple of weeks ago I reported here about the new measurement of the Higgs boson mass produced by the ATLAS experiment. That determination, which used the full dataset of Run 1 proton-proton collisions produced by the LHC in 2011-2012, became and remained for two weeks the most precise one of the Higgs mass. Alas, as I wrote the piece I already knew that CMS was going to beat that result very soon, but of course I could not say anything about it... It ached a bit!

Forty-eight centuries ago, a bronze-age settlement flourished on the southern coast of Peloponnese, about 30 miles south of what would two thousand years later become the important town of Sparta. The city had a harbour facing east on calm waters, and had a few dozen buildings, roads, a burial site, and probably more. We do not know its ancient name, so the place has been called with the name of the modern-times place, Pavlopetri.

Do you remember the top quark asymmetry measurements of CDF and DZERO ? A few years ago they caused quite some excitement, as both experiments were observing a departure from standard model expectations. This could really be the place where one would first observe new physics associated with top quark production, so the analyses triggered quite some theoretical investigations, deeper studies, and model building.

When I was five years old I used to be sort of an attraction to relatives. One of my mother's brothers is an engineer, and he was amazed by my ability to do complex calculations by heart. But to me it was only amusing to observe their amazement for what I considered a triviality.On one occasion - I remember it as it was yesterday - my uncle picked me up and while he kept me with his arms he asked me "Ok, let's see this. Tommaso, what is the square root of 5968?". Mind you, I do not remember the exact number; I only recall it was between 5000 and 7000. I watched up into the void for two seconds, and I replied "77.3". Uncle Ciccio put me down and ran for the pocket calculator - he did have one, although they were a real novelty those years.

The Cornell arxiv is known to not accept preprints without a minimal screening of their contents. Still, I am sometimes led to wonder if a similar attention is paid to the liberty that authors at times take with the titles of their papers. I am officially on vacation since yesterday, so you should not expect the list below to be a very comprehensive one. I just offer four examples of titles that might have been considered for some form of moral suasion toward the author by the arxiv managers, but apparently haven't. I just quote some titles below which struck me as kind of odd.

The muon is a remarkable particle, and its characteristics continue to be of interest eighty years after its discovery despite the fact that we have measured them better than almost anything else around. So, for instance, the muon lifetime is known to better accuracy than that of any other unstable particle; and the muon anomalous magnetic moment remains at the top of our list of things to determine more precisely nowadays.