A photo from open sources Physicists working with results experiments at the Large Hadron Collider at CERN, reported the discovery of two previously unknown massive particles. Team of scientists analyzed the data obtained during the BaBar experiment, which was conducted in 2006 by a team of Stanford physicists.
Then the researchers noticed two energy surges, but not could find an explanation for them.
Now, a group led by Tim Gershon from University of Warwick in the UK announced that energy bursts were caused by the presence of two massive particles, mesons. The mass of each of these particles, which so far have received code names DS3 * (2860) and DS1 * (2860), almost three times the mass of the proton and corresponds to 2.86 GeV.
“The results of our research clearly indicate what exactly these particles cause an energy surge in BaBar experiment, “says Gershon, lead author of the new research.
The laws of particle physics say that mesons are compound particles consisting of two elementary particles of quarks. They are components of matter and are considered indivisible, i.e. non-decaying.
The quarks inside the mesons are connected by the so-called strong interaction, which, unlike other fundamental interactions, increases as the distance between elementary particles. Recall that the same force holds the nucleus atoms together.
Strong fundamental interaction is the least the studied phenomenon of the Standard Model of particle physics. However, it is this field of knowledge that describes the interaction of particles in The universe.
Quarks are known to be divided into six different flavors: top, bottom, weird, charming, pretty and true. New particles contain one charming antiquark and one strange quark. It is noteworthy that DS3 * (2860) also has spin value of 3. This means that in this experiment physicists for the first time in history saw a meson with a spin value of 3, containing a charming quark.
The remaining mesons that scientists have ever observed have such a combination of quarks that the value of their spin cannot exceed or equal to three, which makes the exact properties of quarks ambiguous. However, with a spin value of 3, this the ambiguity disappears, and the exact configuration of the DS3 * particle (2860) it becomes much easier to define.
Gershon and his colleagues note that the unusual properties of a particle DS3 * (2860) make it an ideal example for exploring the strong interactions, since the calculations for massive quarks are significantly more accurate than for the lungs.
The discovery was made possible primarily because for energy burst interpretation in data and identification two particles at once used an innovative compilation technique Dalitz diagrams. Physicists note that this technique has never been not used to process data obtained at the LHC.
This technique allows you to separate and visualize various the ways in which the particle can make its decay. After successful testing of the Dalitz chart, scientists hope that he will continue to be used to interpret these experiments on TANK. In the future, with the help of similar studies, it will become possible discovery of new, possibly even more exotic elementary particles.
Particle Monitoring Articles DS3 * (2860) and DS1 * (2860) and data analysis using the Dalitz chart so far posted on the site preprints arXiv.org. Scientists accepted for publication in journals Physical Review D and Physical Review Letters.
Hadron Collider
