QUARKS: The Stuff of Matter

Surprisingly, quarks have been around for almost 20 years: Murray Gell-Mann and his Cal Tech colleague George Zweig introduced them to the world in 1964, along with Gell-Mann's Joycean coinage for the ""stuff of matter."" Since then, Fritzsch (Max Planck Institute for Physics, Munich) has been a prominent contributor to the successive discoveries, refinements, and clarifications that have turned early scoffers into believers and made believers even more zealous to track quarks to their innermost lairs. Here, he endeavors to guide a conscientious reader through the thickets of hadrons and leptons, and to explain the evolution of strangeness, charm, flavor, and other exotic indices that characterize quarks. Enlightenment will largely depend on the reader's sophistication and occasional blind faith. Nonetheless, Fritzsch lays out the data and diagrams in an orderly fashion that carries conviction. There are glimmers of clarity as he sets forth the background--weak and strong interactions among nuclear particles, early models, analogies between quantum electrodynamics and ""chromodynamics""--and those with some mathematical background cannot help but be intrigued by the group theoretic structures that model the quark compositions of what used to be thought of as the elementary particles (protons, neutrons, etc.). The air gets rarefied, however, as more recent speculations unfold and we hear of vacuums that are not quite vacuums, virtual particles, and newly proposed unified theories concerning the forces governing interactions of matter. What remains, however, is a fundamental excitement. Quark theory has been wonderfully predictive: the omega minus particle was detected, quark ""jets"" have been documented--though nobody's seen a genuine quark on the loose to date. That will require--guessably--even more giant machines to accelerate particles, creating the delicious picture of physicists at CERN, Fermi lab, and other centers relentlessly perusing the infinitesimally small with the superhuge. The intimations are exhilarating, if the particulars are sometimes less than comprehensible.