Scientists from the Beijing-based Institute of High Energy Physics (IHEP), the Chinese Academy of Sciences (CAS) and the University of Hawaii recently reported the discovery of a new sub-atomic particle known as "X1835."
"If this discovery is accompanied by more experimental data, it is likely to deepen our understanding of how matter is formed," said Jin Shan, a senior physicist at the IHEP.
The discovery was made with the Beijing Spectrometer (BES) at the Beijing Electron Positron Collider (BEPC). The particle's mass is slightly less than twice the proton mass. Its lifespan is also very short, about 10-23 seconds.
The results were published in the December 31 edition of Physics Review Letters, one of the world's premier journals for physics research. The discovery was first reported early last year, however.
Tord Ekelof, a professor at Uppsala University in Sweden and a leading international physicist, highly praised the discovery.
"This could be the first evidence that matter and anti-matter can be bound together to become a new form of matter. It is a very important discovery in physics," Ekelof said at an international high-energy physics conference in Sweden last July.
Jin says the X1835 has received considerable attention from the international high-energy physics community. High-energy scientists have conducted experiments for over 30 years in search of it because of the possibility that it could be a new kind of particle.
Almost all known particles that experience strong nuclear force are composed of either two or three quarks, the smallest known material. Yet particle physicists have long predicted the existence of other types of particles, including those containing more than three quarks, or those made of gluons and quarks.
Experimental observations of any new types of particles would be an important verification of traditional particle physics theories, said Jin.
"However, to really pin down the nature of the X1835, more experimental and theoretical efforts are needed, and more experimental data is especially essential. The name X reflects that its structure is not fully understood yet," Jin said.
The discovery of the X1835 is one of the most important achievements of the BES collaboration, which is composed of physicists from more than 20 institutions from China, the United States and other countries, Jin said.
(China Daily 02/07/2006 page7)
