The measured abundance of helium in the universe (about 25% of all normal matter) suggests that there is about one proton for every 1010 photons. This in turn suggests that at some earlier phase of the universe an almost equal number of protons and anti-protons existed and gradually annihilated, but that because of some fundamental asymmetry (at the level of one part per ten billion) in the way that the weak nuclear force treats matter and antimatter, protons but not anti-protons survived to the present time.
The standard model of particle physics usually enshrines this asymmetry in the form of "CP violation," a mathematical convention concerning the interaction of particles in which one imagines what happens when the charge of all the particles is reversed (charge conjugation, abbreviated as C) and the coordinates of all particles is reversed (the parity operation, or P).The standard model is successful in predicting how CP violation works out in the decay of K mesons or B mesons (see Update 600) but not so good at predicting where the abundance of baryons (protons plus neutrons) comes from.
Phil Schewe | Physics news update 614
Pulses of electrons manipulate nanomagnets and store information
21.07.2017 | American Institute of Physics
Vortex photons from electrons in circular motion
21.07.2017 | National Institutes of Natural Sciences
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
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