Scientists from Novosibirsk State University and the Institute of Nuclear Physics attended the Large Hadron Collider conference wh ere the discovery of a “doubly charmed” particle was presented

At EPS HEP 2017 in Venice, the largest conference of the year on the physics of elementary particles, the LHCb collaboration of the Large Hadron Collider (LHC) presented the discovery of a new particle. About 1000 scientists from around the world participated in the LHCb experiment, including scientists from Novosibirsk State University and Institute of Nuclear Physics (INP) SB RAS.


“On July 6 a report was made by Patrick Spradlin. The particle was found by analyzing 1.7 fb-1 data collected as part of the 2016 LHCb experiment at a collision energy of 13 TeV protons.  The data was analyzed during the year and the final result obtained before the conference. The existence of baryons containing two charmed quarks was predicted by the quark model, but so far, no such particles have been observed. In the future, measurements of the properties of this particle will be carried out such as the lifetime and the search for other decay channels," said Senior Researcher at the Laboratory of Heavy Quark Physics in Hadronic Interactions at the INP SB RAS and Novosibirsk State University Pavel Krokovny.  

The new particle is the baryon Ξcc ++, containing two c (charm) quarks. Its decay into the Λc + baryon, two π + mesons and kaons K- was used. The measured mass of the new particle, 3621 MeV / c2, is almost 4 times larger than the mass of the proton, the lightest baryon. This is due to the presence of two c-quarks in it. The analysis of the data confirms that this particle has an appreciable lifetime, that is, it decays with the aid of weak interaction.

Researchers in joint laboratories at Novosibirsk State University and INP SB RAS currently participate in three LHC experiments: ATLAS, CMS and LHCb. Scientists from the Heavy Quark Physics Laboratory in Hadronic Interactions at the Interdisciplinary Center for Elementary Particle Physics and Astrophysics in the NSU Physics Department are involved in the LHCb experiment.