Physics

In a recent PNAS paper, scientists have described how they managed to achieve a quantum entanglement with a minimum of 103 dimensions with only two particles.

103 dimensions rather than 3? Is that a typo?

Elementary particles such as photons can produce superpositions - where they exist in many possible quantum states simultaneously. In addition, when two particles are entangled a connection is generated so measuring the state of one (whether they are in one place or another, or spinning one way or another, for example) affects the state of the other particle instantly, no matter how far away from each other they are.


Now that we know that the Higgs boson has a mass of 125 GeV and displays all the properties that a regular standard model Higgs boson should have, one question you could ask is, is it possible that a top quark decays into a Higgs boson ?

The question is a legitimate one since the top quark has a mass 40% larger than the Higgs, so in principle a decay could be allowed. For instance, one could imagine that the top "fluctuates" into a bottom quark - W boson combination, then that the W boson emits a Higgs particle, and finally the bottom quark and W boson fuse themselves into a charm quark. Or, once the top fluctuates into a Wb pair, it is the bottom quark which emits the Higgs boson before rejoining with the W creating a charm quark. The diagrams are shown below.
Would the existence of B-modes in the cosmic microwave background (CMB) radiation be an evidence for inflation? Many influential colleagues claim that this is indeed the case. But their arguments are based on standard cosmological schemes.

Actually, pre-Big Bang patterns beyond conventional cosmology do not require inflation and can generate CMB B-modes.

Two papers by the BICEP2 Collaboration :

BICEP2 I: Detection Of B-mode Polarization at Degree Angular Scales, arXiv:1403.3985

As a child, you may have been fascinated to learn that draining the water from a bathtub causes a spinning tornado to appear.

That or gravity may have been your first introduction to classical mechanics. As the water rotated faster, a vortex appeared.

Yet if the water is extremely cold liquid helium, the fluid will swirl around an invisible line to form a vortex that obeys the laws of quantum mechanics. Sometimes, two of these quantum tornadoes flex into curved lines, cross over one another to form a letter X shape, swap ends, and then violently retract from one another—a process called reconnection.


I received the following comment from Bo Thide', one of the authors of the paper where Fabrizio Tamburini and collaborators explain their novel method to multiply the transmission of information via EM waves (see here). I think his points are of interest to many so I decided to elect his comment to a independent posting here.

By the way, Bo Thide' is a Swedish professor at the Uppsala department of Physics and Astronomy. For his CV see here.

Comments welcome...

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From Bo Thide':
At 125 GeV of mass, the Higgs boson is a very heavy particle; yet its natural width is predicted to be of just 4.15 MeV in the standard model, a value much smaller than that of particles of similar mass. The top quark, for instance, has a width of 1.5 GeV; and the Z boson has a width of 2.5 GeV: three orders of magnitude larger.

The Higgs boson, colloquially called the God Particle because of its fundamental nature, may not be the smallest particle out there. Well before the Higgs had even been found at the Large Hadron Collider, there were lots of hypotheses put forth as to what forces and particles might make up its existence.

Thomas Ryttov, particle physicist and associate professor at the Center for Cosmology and Particle Physics Phenomenology (CP ³ - Origins) at University of Southern Denmark, says what he calls the most important of these hypotheses has been critically reviewed and that the existence of smaller yet unseen particles is now more likely than ever. 

"There seems to be no new or unseen weaknessess. My review just leaves them just stronger," he says.


The first reported direct detection of gravitational waves via the B-mode polarization of the CMB may have supported the simplest and most popular inflationary models.  Results from the European Space Agency’s Planck CMB observing satellite may or may not contradict these new findings.  Great, what does any of that mean?  I present a plainly worded, but not patronizing, explanation of all this.  The B-mode polarization of the CMB is what it is called but what does that mean and why is it important?  How might this week’s smashing announce

Almost 14 billion years ago, the universe we inhabit burst into existence in an extraordinary event that initiated the Big Bang. In the first fleeting fraction of a second, the universe expanded exponentially, stretching far beyond the view of our best telescopes. All this, of course, was just theory.

Researchers from the BICEP2 collaboration today announced the first direct evidence for this cosmic inflation. Their data also represent the first images of gravitational waves, or ripples in space-time. These waves have been described as the "first tremors of the Big Bang." Finally, the data confirm a deep connection between quantum mechanics and general relativity.
The tau lepton is a particle of very complex phenomenology. Although point-like as its lighter counterparts - the electron and the muon - the tau has a quite respectable mass, 1.77 GeV, which makes all the difference from the other charged leptons.

The tau was discovered in 1975 by Martin Perl at the SPEAR electron-positron collider. The acceptance of that observation was quite slow: the events found by Perl and his team were complicated because of the peculiar properties of the newfound particle. Perl had found an excess of events featuring an electron and a muon and an energy imbalance, which were hard to explain unless hypothesizing the creation of a pair of short-lived, heavy leptons.