NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
This project was supported by the Department of Energy under Grant No. DE-FG0296ER40974, the National Science Foundation under Grant No. PHY-9600688, and a grant from the National Research Council's Basic Science Fund.
International Standard Book No 0-309-06037-0
Library of Congress Catalog Card No. 97-81203
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Copyright 1998 by the National Academy of Sciences. All rights reserved.
Front cover: The power of micro-vertex detectors, a new technology, is used to depict an interesting high-energy event. The detectors (shown in grey) are made of silicon and surrounded the collision point where high-energy interactions took place at 300,000 per second. The inner detector was located 3 cm from the collision point, and all detectors had spatial resolutions of about a thousandth of a centimeter. This fine resolution, needed to resolve the high density of tracks (some of which are shown in green and red), allows accurate extrapolation into the interaction region, inside the beam pipe—shown by the inner circle. The green tracks come from the original interaction, whereas the red ones come from two disconnected points. The latter are actually from B mesons that were created at the collision point but traveled several millimeters before decaying. The detector technology clearly reveals such decays even though the mean life is only a billionth of a second. From other information collected, one knows that this event is an example of the production of a pair of the very heavy top quarks, recently discovered by the CDF and DO collaborations at Fermilab. (Courtesy of Joseph Incandela, CDF and Fermilab.)
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