[en] The underground facility at Kamioka can be extended to be one of the active centers for the future high energy physics in Japan. It will focus on the ultra-high energy physics through searches for rare phenomena. (author)

[en] Physics issues of the e⁺e^- linear colliders are reviewed in the hundreds GeV to TeV region, as a part of the effort to design the future plan of Japanese high energy physics. In this report, we rather begin with the question of ''physics below TeV.'' and ''hadron versus e⁺e^- colliding beams''. We then try to perform detailed analyses on simulated events of various test reactions to see what we could realiastically perform with a e⁺e^- collider in TeV region. Then follow reconstruction of the final state and implications of the exercise. (Mori, K.)

[en] The Linear Collider Study Group conceived the plans of a e⁺e^- linear collider in the TeV region and has proceeded with its design study. For the RF source a lasertron was examined in the course of research and development. For the purpose of further extending the efforts firmly, an overall design has been made of the 1 TeV x 1 TeV e⁺e^- linear collider. Boundary conditions in the design are the realization of 1 TeV x 1 TeV within this century, the power available up to 300 MVA, overall length up to 30 km, luminosity 10³³ cm^-2sec^-1, etc. Contents are the following: an outline of the linear collider, beam dynamics, accelerating tubes, microwave source, injector, final focussing system, detector. (Mori, K.)

[en] We show cross sections of various processes and introduce the cluster analyses suitable to multi-jets events. (author)

[en] Discussions were carried out on computing requirements for future hadron collider experiments. These requirements contains not only data aquisition and online monitoring but following items such as detector design and software development, higher level trigger processing, raw data processing, physics analysis, Monte Carlo Simulations, and networking. This report deals with brief considerations on the abovementioned items and possible solutions for these problems in respect to computing requirements corresponding to the capability of M200H equivalents, vector and/or parallel data processing, optical disk recording, reduction technology of 100 MH₂ triggers to 1 H sub(z), networking of very high band width. It was concluded that large amount data processing from a future hadron collider detectors was very interesting in the technological basis. If computing cost reduction could be achieved, it was concluded that total computing power necessary for the development of 100 - 200 M200 equivalents might become available. Technological developments such as optical recording shall accompany the above-mentioned computer upgrading. Development of multi-micro-processor farms is also required especially for the on-line high-level filtering and increasing off-line computing power. The requirements of reduction of 100 MH sub(z) triggers to 1 MH₂ looked very difficult to solve in the present technical basis but they should be solved by continuing studies and continuous information exchanges on this subject. (Takagi, S.)

[en] Monte Carlo code ISAJET developed by Paige was used to generate the W⁺W^- pair and QCD jets and to see whether the hadronic decay of W boson is distinguished from QCD jet or not. The conclusion is that a considerable number of QCD jets have the structure in the energy flow similar to that of W boson. So it will be very hard to discriminate between the hadronic decay of a weak boson and a QCD jet only by a hadron calorimeter. (Aoki, K.)

[en] Upgrading the KEK 12 GeV proton synchrotron and its booster is significant for the creation of new physics, the high-grade education and cultivation of physicists of next generation and the impacts on other domains of science. The new accelerator complex is proposed and this should attract great enthusism among various science communities. The time schedule will be construction of a super booster in 1987 - 1989, improvements in the main ring in 1986 - 1988, constructions of secondary and primary areas in 1987 - 1991 and a heavy ion injection facility in 1990 - 1991; the main ring to be converted to a superconducting synchrotron in 1990s. Contents are the following: new wave of particle physics, the border region between particle and nuclear physics, possible PS upgrading, etc. (Mori, K.)

[en] What experiments would be like at a multi-TeV hadron collider and the feasibility of a general-purpose detector to uncover new phenomena in such a high energy machine are described. Although much R and D is needed in almost every part, a 4π detector can be built and operated at the maximum luminosity of up to 10³³ cm^-2s^-1. But the detector must be necessarily big and costly. The typical size is about (20 m)³, the weight is about 20 ktons, the number of channels is about 1/2 million, and the cost is about 250 M$. The construction will take as many years as that of the machine itself. An intense program of R and D on every aspect must be vigorously pursued. (Mori, K.)

[en] The possibility is estimated to find the heavy Higgs boson with multi-tens-TeV hadron colliders. Production cross section of the heavy Higgs is quite large. The dominant process is the intermediate vector boson (IVB) fusion. The heavy Higgs boson decays predominantly into a WW or ZZ pair with the branching ratio of - 2/3 for WW and - 1/3 for ZZ. Helicity states of these vector bosons are dominated by longitudinal polarization. These W or Z further decay into a jet pair or a lepton pair. We concentrate on the cases where one of the vector bosons decays into a jet pair and the other into a lepton pair. In order to get a general view, we study the decay modes with a simple Monte Carlo simulation. We estimate event rates for the signals and backgrounds and investigate the possibility to find the heavy Higgs. (Mori, K.)

[en] A variety of physics topics to test and to go beyond the standard model can be studied with the superconducting super collider (SSC) or with the large hadron collider (LHC). We focus on specific subjects at high energy hadron colliders and report on a simulation study of the feasibilities of detecting the W jets and the heavy quarks of the 4 th generation. The second subject of our simulation study is identification of heavy quarks of the 4 th generation. The question of how many quark/lepton generations are is one of the outstanding puzzles in the understanding of particle physics. The SSC or LHC with its huge CMS energies available provides a good place to search for new heavy particles. (Mori, K.)