Physics

Ultra-short X-ray flashes have enabled scientists to watch electrons jumping between the fragments of exploding molecules. The study reveals up to what distance a charge transfer between the two molecular fragments can occur, marking the limit of the molecular regime.

The technique used can show the dynamics of charge transfer in a wide range of molecular systems. Such mechanisms play a role in numerous chemical processes, including photosynthesis.


Have physicists conquered the scaling behavior of exotic giant molecules?

When a two-body relation becomes a three-body relation, the behavior of the system changes. The basic physics of two interacting particles is well understood but the mathematical description of a three- or many-body system becomes so difficult that calculating the dynamics can blast the capacities of even modern super computers.

Under certain conditions, the quantum mechanical three-body problem may have a universal scaling solution and  physicists from Heidelberg University say they have experimentally confirmed such a model. The scientists under Prof. Dr. Matthias Weidemüller investigated three-particle molecules, known as trimers, under exotic conditions. 

The U.S. Department of Energy has given the green light to the LUX-Zeplin (LZ) experiment, which wants to help figure out dark matter, an invisible substance that must make up a lot more of the universe than visible matter does. It is essentially a scientific placeholder because whatever it is should explain a number of important behaviors of the universe, including the structural integrity of galaxies. 


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.
I guess every profession has its own kind of personalized spam. Here is a couple of recent samples from my own:

  • From a Fermilab address: "According to the TRAIN database training for course FN000508 / CR - Workplace Violence and Active Shooter/Active Threat Awareness Training expired on 07/01/2014. Please make arrangements to take this class. If this training is no longer required then you or your supervisor should complete the Individual Training Needs Assessment [...]"
Note that
(1) I am not a user any longer, so their database is at fault. They still send out these notifications anyway.


Recently this headline on Real Clear Science caught my eye: Carbon-12 Nucleus Shaped Like Equilateral Triangle.  It led to an article in Physics World, entitled

In the 1980s, the discovery of soccer-ball-shaped carbon molecules called buckyballs helped to spur an explosion in nanotechnology research.

Now, there appears to be a new ball on the pitch - a cluster of 40 boron atoms forms a hollow molecular cage similar to a carbon buckyball. It's the first experimental evidence that a boron cage structure, previously only a matter of speculation, does indeed exist.

Carbon buckyballs are made of 60 carbon atoms arranged in pentagons and hexagons to form a sphere—like a soccer ball. Their discovery in 1985 was soon followed by discoveries of other hollow carbon structures including carbon nanotubes. Another famous carbon nanomaterial—a one-atom-thick sheet called graphene—followed shortly after.


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!

The 37th International Conference on High Energy Physics (ICHEP) began last Thursday in Valencia, Spain with three days of parallel sessions, now moves on to plenary sessions until Wednesday, summing up the current state of the art in the field. The plenary sessions will be webcast.
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.