Most of the laws of nature treat particles and antiparticles equally, but stars and planets are made of particles, or matter, and not antiparticles, or antimatter. That asymmetry, which favors matter to a very small degree, has puzzled scientists for many years.

New research by UCLA physicists, published in the journal Physical Review Letters, offers a possible solution to the mystery of the origin of matter in the universe.
Alexander Kusenko, a professor of physics and astronomy in the UCLA College, and colleagues propose that the matter-antimatter asymmetry could be related to the Higgs boson particle, which was the subject of prominent news coverage when it was discovered at Switzerland`s Large Hadron Collider in 2012.
Specifically, the UCLA researchers write, the asymmetry may have been produced as a result of the motion of the Higgs field, which is associated with the Higgs boson, and which could have made the masses of particles and antiparticles in the universe temporarily unequal, allowing for a small excess of matter particles over antiparticles.
If a particle and an antiparticle meet, they disappear by emitting two photons or a pair of some other particles. In the "primordial soup" that existed after the Big Bang, there were almost equal amounts of particles of antiparticles, except for a tiny asymmetry: one particle per 10 billion. As the universe cooled, the particles and antiparticles annihilated each other in equal numbers, and only a tiny number of particles remained; this tiny amount is all the stars and planets, and gas in today`s universe, said Kusenko, who is also a senior scientist with the Kavli Institute for the Physics and Mathematics of the Universe.

sursa: www.phys.org

 

Polarisation oscillation rather than modulation of light intensity
To date, information in server farms is transported directly between individual computers via glass fibre cables. Semiconductor lasers generate light pulses; the information is coded in the changes to light intensity. The faster light intensity is varied, the faster information is transferred. Maximum speed is limited by fundamental physical laws, however. Therefore, the RUB team headed by Prof Dr Martin Hofmann and PD Dr Nils Gerhardt does not modulate light intensity but uses light polarisation instead.

Aligning spins and generating oscillating polarisation
Using a laser, the RUB researchers generate a specific circularly polarised light, in which the polarisation direction oscillates, i.e. alternates between two rotational directions. It is possible to make this oscillation much faster than to change the laser light intensity. The reason: variation of light intensity through electric-current modulation is based on the motion of many electrons that cannot be shifted at any chosen speed. Polarisation oscillation, on the other hand, is based on a quantum-mechanical property of electrons, namely the spin, and the motion of a few electrons is sufficient therefor. By orienting the spins of a group of electrons in the laser into the same direction, the researchers generate oscillating polarisation. They have decoded the underlying effect in detail.

sursa: www.phys.org