Showing posts with label cp violation. Show all posts
Showing posts with label cp violation. Show all posts

Fifty years of CP violation

via @CERN http://t.co/9Rac42mBVh #CPviolation #CPsymmetry #matter #antimatter
The CP violation is a violation of the CP-symmetry, a combination between the charge conjugation symmetry (C) and the parity symmetry (P).
CP-symmetry states that the laws of physics should be the same if a particle is interchanged with its antiparticle, and then its spatial coordinates are inverted.
The CP violation is discovered in 1964 by Christenson, Cronin, Fitch, and Turlay (Cronin and Fitch awarded the Nobel Prize in 1980) studying the kaons' decays and it could have a key-role in the matter-antimatter imbalance.
Now the CERN Courier dadicated a special issue about the fifty years of the discovery (download here).
Christenson, J., Cronin, J., Fitch, V., & Turlay, R. (1964). Evidence for the 2π Decay of the K_{2}^{0} Meson Physical Review Letters, 13 (4), 138-140 DOI: 10.1103/PhysRevLett.13.138

In search of violations

This week high-energy physics published some interesting results for our fundamental knowledge of the universe. On 14th November, LHCb published the preliminar analysis about a possible CP-violation in charm decays (see also the CERN's Bulletin and Mat Charles' presentation).
The researches about CP-violations are very important because in this way we can argue the differences between matter and anti-matter. If a physics law is CP-invariant, we must write that the beahvior of matter and anti-matter is the same. But our universe is constituted by matter and we don't know why it is so. The answer could be in CP-violation studies, like the preliminary data analyzed by LHCb team. The main goal of the experiment is the search of the properties of quark b, but he could also measure the properties of quark c. And studying the preliminary data about c decays the team find a clue of a CP-violation in a non expected channel. Following Tommaso Dorigo and Marco Delmastro (english translation by Google), if the result will be confirmed by further analysis, this could be the first sign of physics beyond Standard Model.
The other possible violation is the wall of the speed of light: indeed, OPERA experiment confirm their previous data. Yesterday, in the updated version of their famous preprint, OPERA's researchers described a new serie of measures realized with CNGS using a short-bunch wide-spacing beam.