A Quantum Diaries Survivor

In over 15 years of blogging, in this and previous sites, I have mostly stayed away from the topic of climate change, the environmental catastrophe we are creating with our "perennial growth" myths and our disdain of our planet and the other species that inhabit it, and the continuous slaughter of over a billion animals every year for our unnecessarily opulent lunch tables. 

Today I am back from one of the most interesting workshops I ever attended to, and I wish to share some thoughts I had on possible ways to enhance our research of new ideas for future particle detectors with you. Those ideas come from discussions with other participants to the workshop, or just from re-digesting things I have been pondering over for a while. 

To appreciate what B mesons are, and what is the magic of their behaviour, which is the topic of this article, I need to give you a three-paragraph introduction below.At the smallest distance scales, matter is made of quarks and leptons, which we consider as point-like objects endowed with different properties and interactions. Most of the matter around us is in fact made up of three-quark systems: protons and neutrons, organized in tightly packed nuclei kept together by the strong force; with electrons (which are the lightest charged leptons) orbiting around them thanks to the electromagnetic force attracting them to the protons. 

Physicists from the CMS experiment at CERN's Large Hadron Collider have used the total data sample of 13 TeV proton-proton collisions collected in the past few years to search for resonant decays of heavy hadrons into pairs of J/Psi mesons, and they found three of them. One of the three new resonances is likely to be the same as a particle already identified for the first time by the competitor LHCb experiment, while the other two are new finds. LHCb is also a LHC detector, but it is one optimized for heavy hadron spectroscopy; while CMS is a "general purpose" detector built with the primary goal of finding the Higgs boson (a 2012 success) and searching for new phenomena at the highest-energy frontier. 

Yes, I know - I have touched on this topic already a couple of times in this blog, so you have the right to be bored and surf away. I am bound to talk about this now and then anyway, though, because this is the focus of my research these days. Recently I was in the Elba island (a wonderful place) for a conference on advanced detectors for fundamental physics, and I presented a poster there on the topic of artificial-intelligence-assistend design of instruments for fundamental physics. Below is the poster (I hope it's readable in this compressed version - if you really want a better pic just ask).

Neural networks are everywhere today. They are used to drive vehicles, classify images, translate texts, determine your shopping preferences, or finding your quickest route to the supermarket. Their power at making sense of small or large datasets alike is enabling great progress in a number of areas of human knowledge, too. Yet there is nothing magical about them, and in fact what makes them powerful is something that has been around for century: differential calculus.

When I explain to the public (in this blog, or at public conferences or schools) how the Large Hadron Collider operates, I have to gloss over a lot of detail that is unnecessary to grasp the important concepts, which enable other discussions on interesting subnuclear physics. This is good practice, and it also saves me from having to study details I have forgotten along the way - they say that what you are left with when you forget everything is culture, and I tend to agree. I have a good culture in particle physics and that's all I need to do some science popularization ;-)

As the twentythree regular readers of this blog know [(c) A.Manzoni], in recent times I have moved the main focus of my research to advanced applications of deep learning to fundamental science. That does not mean that I am not continuing to participate in the CMS experiment at the CERN Large Hadron Collider - that remains the main focus of my research; but it does mean that what remains of my brain functionalities is mostly invested in thinking about future applications of today's and tomorrow's computer science innovations. 

I was happy to meet Giorgio Bellettini at the Pisa Meeting on Advanced Detectors this week, and I thought I would write here a note about him. At 89 years of age Giorgio still has all his wits around him, and he is still as compelling and unstoppable as anybody who has met him will recall. It is a real pleasure to see that he still attends all sessions, always curious to hear the latest developments in detector design and performance. 

Two recent analyses by the CMS experiments stand out, in my opinion, for their suggestive results. They both produce evidence at the two-three sigmaish level of the signals they were after: this means that the probability of the observed data under the no-signal hypothesis is between a few percent and a one in a thousand, so nothing really unmistakable. But the origin of the observed effects are probably of opposite nature - one is a genuine signal that is slowly but surely sticking its head up as we improve our analysis techniques and collect more data, while the other is a fluctuation that we bumped into. 

The recent precise measurement of the W boson mass produced by the non-dead CDF collaboration last month continues to be at the focus of attention by the scientific community, for a good reason - if correct, the CDF measurement in and of itself would be the conclusive proof that our trust in the Standard Model of particle physics when producing predictions of particle phenomenology needs a significant overhaul. 

My attendance to the JENAS symposium in Madrid this week provided me with the opportunity to meet some of the senior colleagues who will influence the future development of technologies for fundamental research in the coming decade and more. Over coffee-break discussions, poster sessions, and social dinner I exploited the situation by stressing a few points which I have come to consider absolutely crucial for our field. Of course I am moved not only by caring for the progress of humanity but also by the fact that I would like the research plan I have put together in collaboration with a few colleagues to succeed... Ultimately, the two things are very well aligned though!