Physics

The ATLAS Collaboration has released last week the results of a careful analysis of a large dataset of proton-proton collisions acquired during Run 2 of the Large Hadron Collider. This is a measurement of CP violation effects in the system of B hadrons. Although LHC and ATLAS are things that readers of Science20 may be acquainted with, I realize that the previous 14-word sentence contains already a mention of at least four unknown entities to 99.99% of non specialists, so I suspect I have to open a parenthesis already now. Very briefly, CP violation is a very peculiar effect that arises in…

One of the most suprising results of the "Machine Learning for Jets" (but really, for particle physics in general) workshop I attended in New York City two weeks ago was the outcome of a challenge that the organizers had proposed to the participants: find a hidden signal of some new physics process in a dataset otherwise made up of some physics background, when no information on the new physics was given, nor on the model of the background.\p> The problem is called, in statistical terms, as one of anomaly detection. In other words, you have an otherwise homogeneous dataset (with many…

The third "Machine Learning for Jets" workshop is ongoing these days at the Kimmel centre of New York University, a nice venue overlooking Washington Square park in downtown Manhattan. I came to attend it and remain up-to-date with the most advanced new algorithms that are been used for research in collider physics, as I have done last year. The workshop is really well organized and all talks are quite interesting, so this is definitely a good time investment for me. The first thing I noticed as I joined the 100-strong audience yesterday was that I am at least 20 to 25 years older than the…

Majorana fermions, particles that act as their own antiparticle and were first hypothesized by Italian physicist Ettore Majorana in 1937, have not been detected after all. A 2017 report of the discovery of a particular kind of Majorana fermion, the chiral Majorana fermion, was a false alarm, finds a new study, which means construction of a topological quantum computer also remains elusive. Some particle physicists are using underground observatories to discover if the ghost-like particle known as the neutrino, a subatomic particle that rarely interacts with matter, might be a Majorana fermion…

There is dark energy as sure as there is light in the world. It just may not be a simple scalar multiplier in our equations as we had hoped it would be. Dark energy is what the scientific consensus says that over 95% of the mass-energy of the universe is comprised of.  This is backed by many studies and a new study to be published in the Astrophysical Journal (1)  which also pairs with earlier research that showed the dark matter may not be the same in every direction (2).    This indicates to my theorizing mind that the dark energy will turn out to be a scalar.…

What hurts you is not what you don't know, but those mistaken assumptions which "everyone knows to be true".[The following text is courtesy Andras Kovacs - T.D.] This post is related to the book entitled "Maxwell-Dirac Theory and Occam's Razor: Unified Field, Elementary Particles, and Nuclear Interactions". This book is authored by Andras Kovacs, Giorgio Vassallo, Paul O'Hara, Antonino Oscar Di Tommaso, and Francesco Celani. The book's first edition is in print, and we are currently working on its second edition. After discussing our work with others peers, it became clear that we need to…

I am currently in Bangkok, where the final 2019 meeting of the CMS collaboration started today. The meeting was inaugurated this morning with an official visit of Her Royal Highness Princess Maha Chakri Sirindhorn, giving me the rare opportunity to miss an appointment with a princess, something that was still missing from my repertoire. Checked now. At the opening plenary session, which is being held in a spacious conference room at the Mandarin Hotel, I am sitting in the second row. Two large screens stand in front of the audiences on the left and on the right, so the speakers have…

Last month the Museum of Natural History of Venice hosted, in the last room of the exhibit called "room of the cetaceans" (where a large skeleton of a whale hangs from the ceiling), an exhibit of artwork produced by high-school students from the Venice area. The event, which belongs to the "Art and Science across Italy" project, was the culminating point of a series of lectures on particle physics, on science in art, and related topics which involved the students and INFN personnel from the Padova section. I toured the high schools in Venice, Mestre and Mogliano to give 7 lectures during…

Is there a fifth force of Nature, beyond the four we know about ? This question has been around ever since it was understood that 1 - electric charges attract and repel, and influence one another, due to the action of the electromagnetic force; 2 - hadronic matter is held together by the strong force; 3 - quarks transmute into other quarks due to the action of the weak force (and leptons do that too); 4 - bodies carrying mass feel attracted to one another, although very weakly, by the gravitational force. After electric and magnetic forces were understood in the nineteenth century to be…

[I extorted the text below from my friend and colleague Andrea Giammanco, who has been one of the driving forces behind a new scientific result at the crossroads of nuclear and particle physics - TD] A new result by the CMS collaboration [CMS-PAS-HIN-19-001, cds.cern.ch/record/2699428] demonstrates for the first time that top quarks can be produced in nucleus-nucleus collisions.To provide the context for this breakthrough, let us start by recalling that the flagship accelerator of CERN is named Large Hadron Collider (LHC) and not Large Proton Collider, in spite of being most famous for how…