Title: Super Z Factory and Experimental Physics on It
Speaker: Zhao-xi Zhang, Academician of the Chinese Academy of Sciences, Institute of Theoretical Physics, Chinese Academy of Sciences
Reporting time: 3:30-4:30 pm，June 17, 2019
Reporting location: Xingjian Building 437
Summary of the report:
The only neutral weak gauge particle in the standard model, the Z-Boson, which is capable of resonating in a positive-negative electron collider (the center-of-momentum of the collision is 91 GeV); a dedication to build electron-positron collider running at the resonance energy, a large number of Z-Bosons are produced, together with a large experimental device platform consisting of a matched sensitive detector to be called a Z-Boson sub-factor; using modern accelerators, colliders and detector technology, the colliding brightness of the Z-boson factory is expected to reach 10^36 cm^-2 s^-1 and it can accurately detect the occurrence of the case, so that the highest brightness is different from the Z-boson factory which has been seen in the world. The boson factory is known as the Super Z-Boson Factory which comprehensively and accurately studies the properties of Z-Boson generation, its decaying and decaying secondary particles to look for rare cases, etc. In particular, researching them from the generation to the decay can rigorously test of the particle physics standard model and find the most sensitive discovery of new physics outside the standard model; Super Z-Boson sub-factor is still an experimental platform to study tau lepton physics, heavy flavor physics, heavy flavor and double heavy flavor hadron physics, the hadronization of quantum chromodynamics (QCD), the determination of the fragmentation function, etc. It has irreplaceable advantages. Finally pointing out that in order to meet the development needs of particle physics, the world at least one super Z-Boson Factory needs to be built.
Zhao-xi Zhang, a famous particle physicist, is an academician of the Chinese Academy of Sciences and researcher of the Institute of Theoretical Physics of the Chinese Academy of Sciences. Mainly engaged in particle physics theory research, he is known as Bc-meson research in the world. He published a research paper on the strong generation of J/psi particles based on perturbative quantum chromodynamics and originally proposed a 'color singlet mechanism' that directly produces J/psi particles, which is often cited as a representative paper for this mechanism. Theoretically, he calculated correctly such things ranging from the fragmentation function of b quark, Bc-meson, the transverse momentum distribution to total cross section of the ground state and excited state of Bc-meson. The width of the main decay channel of Bc-meson and the lifetime of Bc-meson are also calculated. He explicitly predicted the way and possibility of experimenting with Bc-meson. In 1998, the experiment of TEVATRON in the United States took the lead in discovering the Bc-meson as predicted by theory. The theoretically produced sub-BCVEGPY and GENXICC, which were written and upgraded in time to produce "double-flavored" particles, have been very useful for experimental research and have been used by several experimental groups. Focusing on the experiments of combining medium and high energy physics in China, he carried out relevant theoretical research and put forward valuable suggestions for our experiments. He has won the first prize of the Natural Science of the Chinese Academy of Sciences and the Wu Youxun Physics Prize of the Chinese Physical Society.