THE ELUSIVE NEUTRINO A Subatomic Detective Story NICKOLAS SOLOMEY For more than 60 years, researchers in particle physics have been pursuing the neutrino. Just developing the technology and the means to detect this subatomic particle took 20 years. Physicists continue to be tantalized by the question of its mass—does the neutrino weigh anything and, if so, how much?—and the unique characteristics of spin and symmetry that set this particle apart from others. In The Elusive Neutrino: A Subatomic Detective Story, University of Chicago physicist Nickolas Solomey takes his readers through the mind-bending world of particle physics, using research involving neutrinos as a navigational tool. Solomey’s discussion spans the history of particle physics from the discovery of radioactivity to present theoretical speculation about the mass and origin of elementary particles. He describes the scientific principles relevant to the neutrino search through the efforts of the scientists who discovered them, sharing their fears and triumphs and making The Elusive Neutrino a human story in addition to a scientific one. He also powerfully demonstrates the synergy of experiment and theory that drives modern science. Is the neutrino its own antiparticle? Can neutrinos account for the missing matter of the universe? In hunting for the answer to these and other questions, physicists have made some of the most exciting and significant discoveries of the twentieth century. Studies of a new kind of neutrino interaction eventually led scientists to a unified theory of electroweak particle interactions—a merging of the theories explaining radioactivity and electromagnetism. This theory explained some previously baffling phenomena and, more important, represents a huge step toward someday discovering the superforce that would explain all particle interactions. Experiments with neutrinos first led physicists of the 1940s to suspect the existence of a veritable zoo of subatomic particles, many more than they had expected. Decades later, studies of the types of neutrinos told physicists how many particles this zoo could contain. In a story that ranges from the unimaginably minute to the unimaginably vast, Solomey also shows us how scientists are studying neutrinos for clues to the origin and (perhaps) the future of the universe. The Elusive Neutrino: A Subatomic Detective Story takes us on a tour of this fascinating branch of physics—a tour that’s not only engaging but enlightening. ABOUT THE AUTHOR Nickolas Solomey is Compton Lecturer of Physics and Research Scientist at the Enrico Fermi Institute of the University of Chicago. An experimentalist in the field of elementary particle physics, he participates in research at the Fermi National Accelerator Laboratory and has also spent several years at the European Center for Nuclear Research (CERN). Cover image: A sulfur ion accelerated to high energies strikes an atomic nucleus in a gold target, producing a spray of hundreds of subatomic particles. This image of the collision, from CERN experiment NA-35, was captured in a special type of light-emitting detector that records the particle trajectories as bright lines. (Courtesy CERN)

Solomey Nickolas

The elusive neutrino, a subatomic detective story