forces of nature and to understand the ultimate structure of matter

in terms of the properties and interactions of its basic constituents.

Although the focus of each of the programs is somewhat different, most experiments in both the High Energy and the Nuclear Physics programs depend on large experimental facilities that accelerate beams of particles to collide with stationary targets or other moving particle beams. These are required to probe the properties of atomic nuclei, in the case of Nuclear Physics, or to study elementary particles such as quarks in the case of High Energy Physics. The primary experimental technique used in both programs is to analyze the results of the collisions. Many entirely new forms of matter can be created in these collisions by means of a series of energy-to-matter transformations. The study of these dynamic phenomena then reveals the properties of the underlying building blocks and basic forces involved. In general, as the particles studied become more elementary, their component parts are bound together more tightly. Thus, larger, more powerful and complex accelerators, detectors and supplementary equipment are required to carry out the research.

Although progress in High Energy and Nuclear Physics is dependent on the availability of these forefront accelerator and colliding beam facilities, as well as on the sophisticated detectors that record the effects of particle collisions, these advanced facilities are only one facet of the program. Progress in both High Energy and Nuclear Physics features a continuing interplay of advancements in experiment, theory and technology. HENP experiments are done at the very forefront of theoretical and technical knowledge, and the range of experiments possible is determined by available technology. Physicists frequently have to invent unique equipment and technology to carry out the experiments of greatest importance. Great strides in technology advancement are now coming at the same time that our understanding in both fields of research is growing rapidly. Together, these advance

ments provide a clear view of the kinds of new experimental facilities that will be required to take advantage of the growing number of successes in recent years.

The large scientific facilities supported by the HENP programs are available to qualified scientists for experimental research on the basis of the merit of their scientific proposals. Approximately 75% of the research in High Energy Physics is done by universitybased scientists who usually form collaborations with scientists from other universities or from DOE's laboratories. Typically, proposals from university and laboratory user groups for accelerator research time are evaluated by scientific program advisory committees which recommend for selection those proposals with the greatest scientific promise. The High Energy Physics program operates almost exclusively in this mode, while Nuclear Physics, in addition to national facilities, also supports dedicated accelerator facilities located on the campuses of four leading universities (Duke, Yale, Texas A&M, and the University of Washington) where research is primarily conducted by resident researchers and graduate students. To complement, interpret, and guide the experimental work, each program supports a vigorous theoretical research effort at universities and at the national laboratories.

HIGH ENERGY PHYSICS

Considerable progress has been made in recent years toward improving our understanding of energy and matter and their most elemental transformations. We have not only identified a growing number of particles, but have seen how they relate to one another and how they can be transformed during collisions with other particles in accelerator experiments. A long-standing goal of high energy physicists is to understand these diverse and complex phenomena by formulating a theory which would encompass all of the interactions of matter and energy revealed by their research. These "unified" and "grand unified" theories, as physicists call them, hypothesized over the last 10 years, imply that the diversity

existing in the universe today may have evolved from a single

force, or process, that existed only when the universe was formed some 20 billion years ago.

These theories aim at linking together, or unifying, the four known fundamental forces of nature and identifying the basic

constituents, or building blocks, of matter. The electromagnetic force describes how atoms and molecules are formed and is the cornerstone to understanding chemistry, electronic communications and biological processes. The weak nuclear force describes processes such as the radioactive decay of nuclei. The strong nuclear force helps describe how the nucleons, and thus all nuclear matter, are held together. The gravitational force, perhaps the most familiar of the four forces of nature, explains such things as why rocks fall and planets move in their orbits. The basic constituents of matter are presently hypothesized to consist of "quarks and leptons." Quarks are thought to be the constituents of nuclear matter. Leptons are weakly interacting particles, like the

electrons, muons, and neutrinos.

Recent research results have led to an increasingly better understanding of the forces of nature. That understanding is defined in theories that indicate that the weak nuclear and the electromagnetic forces are actually different forms of a single force--referred to as the electroweak force. Two U.S. physicists shared in the 1979 Nobel Prize for work on this unification. The 1980 Nobel Prize in Physics was also awarded to two U.S. physicists for work that is expected to contribute to unification theories that encompass the strong nuclear and electroweak forces. Eventually, it is postulated that the gravitational force will be incorporated into a super unification theory, bringing all of the basic forces into a unified framework.

Among the predictions of the new theories is that protons, which were previously thought to be absolutely stable, do eventually decay; and that neutrinos, among the most abundant particles in the

universe and previously thought to be massless, could instead have a small mass. Special emphasis in the experimental program is focused on testing these and other predictions of the unified theories

Advances in experimental research during 1983 were highlighted by the observation at CERN in Geneva, Switzerland of the long-sought particles (called "W" and "Z") which are the carriers of the weak nuclear force. The discovery was made by an international team of researchers which included research scientists from the U.S. The observation of these particles, each of which is almost a hundred times heavier than a proton, was critical to the theory of unification of the weak and electromagnetic forces which had predicted their existence. Significant progress has also been achieved in precision measurements of the results of collisions of high energy electrons and positrons at the Positron-Electron Project (PEP) and the Stanford Positron-Electron Asymmetric Ring (SPEAR) facilities at the Stanford Linear Accelerator Center. Teams of university and laboratory scientists have measured a surprisingly long lifetime of a particle thought to contain one of the heaviest quarks, and have observed the presence of new states of matter resulting from decays of particles containing "charmed" quarks. The long lifetime, interesting in itself, has also given new clues in the search for even heavier particles. interpretation for the new states observed is that they could be made up entirely of the gluons that are thought to be the carriers of the strong nuclear force.

One

The experimental work in High Energy Physics is carried out primarily on the high energy accelerator and colliding beam

facilities operated by the Department. In FY 1985, these include: the 38 GeV (billion electron volts) proton synchrotron, called the Alternating Gradient Synchrotron (AGS), at Brookhaven National Laboratory (BNL); the 1000 GeV superconducting magnet proton synchrotron at Fermi National Accelerator Laboratory (Fermilab); and the 32 GeV linear electron accelerator at the Stanford Linear

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Accelerator Center (SLAC). SLAC also has two electron-positron colliding beam facilities for which the linear accelerator acts as the Stanford Positron Electron Asymmetric Ring

the injector:

(SPEAR) (4 GeV x 4 GeV) and the Positron-Electron Project (PEP) (1 GeV x 15 GeV). Each of these DOE accelerator centers provides a unique set of experimental capabilities, complementary to the others. As an ensemble they provide capabilities essential for a comprehensive forefront national research program in high energy physics. A major part of High Energy Physics funding is required develop, maintain and operate the major accelerator and

to

detector facilities at these laboratories.

Before I discuss the budget request, I would like to report a majo technological achievement during this last year. The Energy Saver the world's first high energy accelerator using superconducting magnets, has been brought into successful operation at Fermilab. The last superconducting magnet was installed in March 1983 and by early July the beam had been accelerated to 512 GeV, a world recor energy. The accelerator is presently providing beam to experiment at 400 GeV. This energy will be increased to approximately 700 Ge in the near future. In FY 1985 the accelerator is expected to operate at energies near 1000 GeV. This is truly a major step in the development of superconducting magnet technology.

FY 1985 HIGH ENERGY PHYSICS BUDGET REQUEST

The FY 1985 request for the High Energy Physics program is $561.0 million, which consists of $381.6 million for Operating Expenses, $65.4 million for Capital Equipment and $114.0 million for Construction (Table 2).