S.H. Wang wangsh@bepc2.ihep.ac.cn
Institute of High Energy
Physics
Beijing 100039, China3mm
The Review Meeting for the Beijing Tau-Charm Factory (BTCF) was held in the Institute of High Energy Physics, Beijing November 4-5. 13 members of the Critical Review Panel attended the meeting, they are M. Davier (co-chairman) of LAL, D. Boussard and J. Kirkby of CERN, W.K.H. Panofsky, A. Chao and J. Dorfan of SLAC, F.J. Gilman of Carnegie-Mellon University, S.Kurokawa of KEK, T.D. Lee of Columbia University, M.`Tigner of Cornell University, and J.L. Xie (co-chairman), S.X. Fang and M.H. Ye of IHEP. President G.Z. Zhou of the Chinese Academy of Sciences made the opening address for the meeting. Z.P. Zheng briefly reviewed the feasibility study results of BTCF, T. Huang described its physics goals, W.G. Li and Y.Z. Wu introduced the detector and accelerator of the BTcF respectively, and S.H.Wang explained the schedule of BTcF's R/D program. Stimulating discussion were then followed.
The panel commended the IHEP management and BTCF study team for their
vision and effectiveness in carrying out the feasibility study for BTCF.
High energy physics is developing along two complementary frontiers; one
pushed to higher energies, the other to greater precision. The next step in
precision physics requires dedicated accelerators, known as factories, which
are optimized for he study of specific particles. B-Factories are presently
under construction in the US (PEP-II) and Japan (KEKB) and a ``strangeness''
factory DA
NE is nearing completion in Italy. The essential machine
that is not yet approved is the tau-charm factory, leaving an important gap
in the world's particle physics program. The absence of a tau-charm factory
elsewhere gives China a unique opportunity to continue at the forefront of
particle physics at modest cost.
The panel has made a realistic assessment for the feasibility of the BTCF: with regard to the accelerator, the high luminosity of BTCF is feasible; the engineering parameters of BTCF, although quite challenging, are somewhat less stringent than the low energy rings of the B-factories that are now under construction; with regard to the proposed detector, feasibility is assured; the technologies incorporated are all currently in use or now under construction for the B-factories and the performance requirements for the BTCF detector are no more stringent than for those detectors.
The panel is very favorably impressed by the BTCF feasibility study report and regards it as an excellent foundation for the R/D program. The panel suggested that the R/D items for the accelerator proposed by the Chinese scientists should be divided into two distinct categories. The first category, such as demonstration of lattice design with adequate dynamic aperture, demonstration of impedance control and superconducting technology, constitutes the R/D that should be well under way prior to project authorization. The second category involves items that have less urgency and can be carried out after construction approval. For the R/D items of the detector, the panel felt that the studies and prototypes proposed by the Chinese scientists were appropriate, but would need to be carried out together with the international collaboration, which would allow optimization of the detector design and establishment of the necessary infrastructure and tools at IHEP.
The meeting recognized that the Chinese Authorities would generally prefer to defer construction authorization until completion of R/D, and concluded that considerable advantage to China would result if a commitment to construction could be made at the earliest possible occasion.
The panel believed that BTCF would have a major impact on world science and there is a broad and important physics program for it to carry out. With this project, China will continue to push the frontier of particle physics; the BTCF should draw substantial international collaboration and prove highly attractive to the community of young Chinese scientists; and it will bring in additional high technology which is very useful for many application in the national economy.