U.S.-Japan Cooperative Science: Theory of Heavy Flavor Decays in the Era of Beauty Factories

University Of Notre Dame, Notre Dame IN

Investigators

Abstract

0089550 Bigi This award supports a three-year collaborative research project between Professor Ikaros Bigi of the University of Notre Dame and Professor Ichirou Sanda of Nagoya University in Japan. The researchers will be researching the theory of heavy flavor decays in the era of beauty factories. CP (Charge/Particle) violation constitutes one of the central mysteries of the successful Standard Model of high-energy physics. CP is the violation of the combined conservation laws associated with charge conjugation (C) and parity (P) by the weak nuclear force, which is responsible for reactions such as the decay of atomic nuclei. Parity, or space inversion, is the reflection in the origin of the space coordinates of a particle or particle system (in three dimension). Parity conservation means that left and right and up and down are indistinguishable in the sense that an atomic nucleus throws off decay products up as often as down and left as often as right. For years it was assumed that charge conjugation and parity were exact symmetries of elementary processes, namely those involving electromagnetic, strong, and weak interactions. Thirty-six years after it was discovered that parity was violated in the weak interaction beta decay, it has not yet been established in any other system. At the same time it is of great cosmological significance as essential for generating the baryon number of the universe. Since theory predicts large CP asymmetries in the decays of beauty hadrons, dedicated experiments are starting to collect data in both the U.S. and Japan. New theoretical technologies have been developed to deal quantitatively with the weak decays of beauty hadrons. One crucial element in this progress has been maintaining close contact with experiments. The promise of this strategy has grown even stronger with huge amounts of new data. The project brings together the efforts of two laboratories that have complementary expertise and research capabilities. The researchers' goal is to gain a better understanding of the phenomenon of matter-antimatter asymmetry, so obvious in nature, but not quite understood. Results of the research could impact on some discovery in the field of B-hadron physics. This research advances international human resources through the participation of graduate students. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. The researchers plan to publish results of the research in scientific journals and report on the findings at scientific meetings.