6 July 2017, at the EPS Conference on High Energy Physics in Venice, the LHCb experimentat CERN’s Large Hadron Collider reported the observation of a doubly charmed baryon, a new particle containing two charm quarks and one up quark. CERN has made a press release of this new detection and the collaboration has submitted a paper reporting these findings to the journal Physical Review Letters.
The mass of the newly identified particle is about 3621 MeV, which is almost four times heavier than the most familiar baryon, the proton, a property that arises from its doubly charmed quark content. It is the first time that such a particle has been unambiguously detected.
“Finding a doubly heavy-quark baryon is of great interest as it will provide a unique tool to further probe quantum chromodynamics, the theory that describes the strong interaction, one of the four fundamental forces,” said Giovanni Passaleva, new Spokesperson of the LHCb collaboration. “Such particles will thus help us improve the predictive power of our theories.”
The LHCb collaboration is comprised of 1185 members from 72 units, 16 countries. Researchers of the Chinese team are from Tsinghua University, Central China University, University of Chinese Academic of Sciences and Wuhan University. According to Giovanni Passaleva, “The LHCb Chinese scientists played a crucial role in the observation of the new particle. They are being rewarded for a long standing and highly recognized experimental effort.”
This new finding has consolidated the place of the Chinese team in the collaboration and won Chinese theorists respect. “A group of Chinese theorists provided also fundamental inputs to drive the analysis to the right direction and gave key suggestions to achieve this result.” said Giovanni Passaleva.
Team CCNU, which is made up of two teachers ( Xie Yuehong and Yin Hang), one post doctor ( Yu Jiesheng) and one doctoral student ( Xu Menglin) made great contribution to the finding of the exceptionally charming particle. “It is an extremely challenging systematic project; every step is crucial. What impressed me the most is that after observing significant signals, we made it to hold our thrills and excitements and continued doing lots and lots of detailed works. We applied many approaches to measure the lifetime of the new particle and finally made sure that this was the one we had been expecting. I’m so happy that the team of CCNU could play such an important role in finding the new particle.” said Xie Yuehong, the principle of the particle physics experiment group of CCNU. The research work of CCNU has won many national and provincial supports.
The observation of this new baryon is just a beginning, other representatives of the family of doubly-heavy baryons art to detect. Team CCNU together with the Chinese team of LHCb will continue the research.
CERN Press Release:
http://press.cern/press-releases/2017/07/lhcb-experiment-charmed-announce-observation-new-particle-two-heavy-quarks
Research Paper:
http://lhcb-public.web.cern.ch/lhcb-public/Images2017/LHCb-PAPER-2017-018.pdf
