Physics

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. Before I explain what I mean with the above, I will mention that the reason for this post was originally to advertise a…

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 ;-)One of the things…

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. In some sense, the kind of CMS work I am presently involved in…

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.  Besides having been a remarkable tennis player in his youth, Giorgio had a bright career as a particle physicist, but I cannot speak about his successes…

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…

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. Note that the above does not mean that the W mass is the only reason to think that our understanding of fundamental interactions between elementary particles is incomplete.…

Despite shutting down its operations in 2011, data from an old experiment at the Collider Detector at Fermilab (CDF) has pushed scientists to further rethink the Standard Model. The CDF re-measured the mass of the “W boson” particle and found that it weighs more than the Standard Model suggests it should. The new measurement is the most accurate measurement ever of the W boson’s mass.  The Standard Model The results of the CDF’s decade-long experiment to measure the mass of the W boson found that the mass of the W boson was slightly greater than expected. That small discrepancy has…

As a test of Einstein’s General Theory of Relativity the Event Horizon Telescope image shows us an extreme example of light being bent by the mass of a black hole. General Relativity (GR) predicts that solar mass objects will do this to some degree which is very hard but not impossible to measure. In the case of a black hole it predicts what Event Horizon Telescope saw to within the measurement precision of the EHT. Any modified theory of gravity that stands a chance would have to match these observations. The image of the light field near the supermassive Black Hole Sagittarius A*.This is…

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…

As I write these few lines, I am sitting in the nice auditorium at CSIC in Madrid, where I came for a congress that is a bit different to many others that take place around the world at all times. Truth be told, covid-19 took a big hit on the organization of these events, but slowly things are getting back to normality - the only visible sign of something different from 2019 in the auditorium is the fact that about 80 percent of the 180 scientists sitting around me wear a mask. The event is the second JENAS seminar (the first was indeed in October 2019, in Orsay), a joint venture of three…