Physics

A first observation of the Omega_b baryon -a quite exotic particle composed of a bottom quark and two strange quarks- has been recently published by the DZERO collaboration. Their paper claims to observe the so-far-unseen particle in 1.3 inverse femtobarns of Run II data (about a hundred trillion proton-antiproton collisions, that is). The claim is based on the signal they find, 17.8 fitted events making a peak in the reconstructed mass distribution, a signal whose significance is computed to exceed five standard deviations: 5.4 of them, to be precise. "Five sigma", as it is dubbed by…

Researchers in condensed matter physics at the University of Pennsylvania and the University of Chicago have created an experimental and computer model to study how jamming, the physical process in which collections of particles are crammed together to behave as solids, might affect the behavior of systems in which thermal motion is important, such as molecules in a glass. The study presents the first experimental evidence of a vestige of the zero temperature jamming transition — the density at which large, loose objects such as gas bubbles in liquid, grains of sand or cars become rigid…

Dark matter, dark energy and scalar tensor vector theories of gravity are widely thought of as at odds.  I have shown that if the scalar and vector fields common to alternative gravities are considered as any other quantum fields on a curved space time the consequence is the creation of particles and matter which need not couple into the electromagnetic force.  In short if there are "extra" fundamental forces of nature then there will be "extra" dark matter particles related to those forces.  (Some people have commented in a way which indicates that they are here looking for a…

With an unexpected move, the Austrian Minister of Research and Science, Johannes Hahn, announced last Friday that he intends to put an end to the 50-year-long participation of Austria to CERN. Such a move is hard to understand, in light of the great prospects of physics that the start-up of LHC will bring at the end of this year. Losing membership to CERN would mean a downgrade of Austrian scientists in all the projects they are involved, and it would be detrimental to the experiments, to the lab, and to particle physics in general, but most of all it would be a catastrophe for Austrian…

Radiation ! The word brings sudden silence and a feel of insecurity. The effect of  nuclear radiation brings the memory of  Nagasaki and Hiroshima. Everyone wishes  to escape from radiation. But can we escape? Really none can. It is here and everywhere. In fact, we are in the sea of radiation. Radiation pervades.   The earth on which we stand is full of radioactive elements. The earth constantly radiating. We also radioactive due to K-40. Air we breathe, the water we drink , the food we eat are all naturally radioactive. As you aware, the Earth is bombarded…

On my way back to CERN from Fermilab (yes, I am betting on two tables at a time these days, as our Poker-addict friend Garth Sundem suggests), I made a 7-hour stopover in New York. Originally this was meant to save money to my employer, because other combinations costed more than the Swiss ticket I found. But I made virtue of necessity, and organized a meeting with my friend Peter Woit in the West Village. It turned out that I picked the right day for my visit. The weather was perfect, albeit a bit windy. I took the metro from JFK to the 42nd street and stopped by Bryant park, one of my…

Chessplayers are a strange lot. Those who get attracted by the game and end up sticking to it, making it the game of their life, are typically intelligent, creative thinkers; yet among them one may usually count a unusually large number of nutcases. It is not a secret, for instance, that several of the best chess players of the past were disturbed souls. Whole books have been written on this topic (see for instance the famous "The psychology of the chess player" by R.Fine), and I cannot offer any meaningful contribution here. However, I can tell you the personal story of the worst moment of…

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Imagine a time when the entire universe froze - according to a new model for dark energy, that is essentially what happened about 11.5 billion years ago, when the universe was a quarter of the size it is today.    A cosmological phase transition, similar to freezing, is one of the distinctive aspects of this latest effort to account for dark energy; a mysterious, unseen negative force that some cosmologists say makes up more than 70 percent of all the energy and matter in the universe and is pushing the universe apart at an ever-faster rate.  Another feature that distinguishes…

When I became an amateur chess player and I enrolled in the "Esteban Canal" chess club in Venice, about a quarter of a century ago, I met and got to know personally dozens of people sharing my interest for the game of the kings. Many of them became good friends of mine, but only maybe two or three have made a permanent dent in my soul and have stayed in my heart since then, despite our lives took different routes. Among this small subset was Francesco, universally known as "chicco" by all those who loved him. Chicco had a volcanic mind, a razor-sharp sense of humour he never turned off, and…