Below I offer a preview of the slides I will show tomorrow at an invited seminar on the rather technical topic of "The b-jet energy calibration with Z-->bb decays", which I have come to CERN to give at a meeting of the LHCb collaboration. As I mentioned already in the first part of this two-part article, the topic is rather technical, and I do not expect a large audience -but I will nonetheless make an attempt at explaining the meaning of the slides pasted below. Then, of course, I am available to provide some additional light on any specific issue among those dealt below which you may want to understand more about.
Tomorrow I am traveling to CERN, where I have been invited to give a seminar at a meeting of the LHCb experiment. My talk will discuss the issue of the energy calibration of b-quark jets, a topic to which I have devoted a good part of my research time for the last thirteen years. The talk will of course be centred on the explanation of the analysis Julien Donini and I, together with a few colleagues, performed in CDF a few years ago, the search for Z boson decays to b-quark jet pairs.
Created in a Bose Einstein Condensate, sound may enter these acoustic black holes but it may not leave. This creates an system we can experiment with on a table top level and learn about black holes from it.
The strange and unique features of the Bose condensate never cease to surprise us. A while back they were used to slow a beam of light almost to a standstill.
Now a research team out of the institute of technology in Haifa Israel claims to have created "A sonic black hole in a density-inverted Bose-Einstein condensate.
" by O. Lahav, A. Itah, A. Blumkin, C. Gordon, and J. Steinhauer (Arxiv link to PDF).
The folks at In the Dark
have come up with A Unified Quantum Theory of Sexual Interaction
. This is the best geek hilarity I've ever seen. It's probably even funnier if you have any idea what they are talking about, in regard to quantum theory. I particularly enjoyed their quip about string theorists "twiddling their thumbs":
Self- interactions involving a solitary phase are generally difficult
to observe, although examples have been documented that involve
short-lived but highly-excited states accompanied by various forms of stimulated emission,
The search for planets capable of sustainable life (as we know it) is on, but with an infinite number of planets astronomers are focusing their attention on each system's 'habitable zone', where heat radiated from the star is just right to keep a planet's water in liquid form.
They have found planets orbiting red dwarf stars because those make up about three-quarters of the stars close to our solar system. Potentially habitable planets must orbit closer to those stars, perhaps one-fiftieth the distance of Earth to the sun, since they are smaller and generate less heat than our sun.
It is a well-known fact that it is much easier to measure a physical quantity than to correctly assess the magnitude of the uncertainty on the measurement: the uncertainty is everything!
A trivial demonstration of the above fact is the following. Consider you are measuring the mass of the top quark (why, I know you do it at least once a week, just to keep mentally fit). You could say you have no idea whatsoever of what the top mass is, but you are capable of guessing, and your best guess is that the top mass is twice the mass of the W boson: after all, you have read somewhere that the top quark decays into a W boson plus other stuff, so a good first-order estimate is 2x80.4= 160.8 GeV.
Core-collapse (or gravitational) supernovae are among the most energetic and violent events in the universe and constitute the final tremendous explosions in the life cycles of stars 8 times more massive than our Sun.
After running out of fuel, the core of such a star collapses and forms a neutron star or a black hole. At the same time, the outer layers are ejected at high velocity (up to 10% of the speed of light) and shine as brightly as billions of stars together.
To provide some perspective, the total energy suddenly released by such a supernova exceeds the total energy release by our Sun to-date; and also in the next 10 billion years.
It feels good, for a die-hard sceptic like I am, to live and let unexplained phenomena die. The phenomena in question are measured deviations from the predictions of the Standard Model (SM), our wonderful theory of subnuclear interactions, which has been condemned to fail by theorists soon after its construction, but continues, disappointingly for many, to succeed in explaining experimental results.
'True muonium' is a long-theorized but never-seen tiny atom that was first proposed more than 50 years ago. True muonium, which unlike "muonium" (an atom made of an electron and an anti-muon) is made of a muon and an anti-muon. Both muons and anti-muons are created frequently in nature when energetic particles from space — cosmic rays — strike the Earth's atmosphere yet their existence is fleeting and their combination, 'true muonium,' decays naturally into other particles in a few trillionths of a second. This has made observation impossible.
But it might be observed even in current collider experiments, according to theoretical work published recently by researchers at the SLAC National Accelerator Laboratory and Arizona State University.
This is going to be a rather long piece, so for the lazy and the absent-minded among you I decided to put together an executive summary at the top, and not at the bottom of the article as I usually do. It is a bit of a spoiler, but those of you who can invest some time reading about particle physics will not be deterred by the first few lines of text. Besides, an executive summary is needed because we are discussing real news here: so here it is.