In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor. In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved; apart from their masses and quantum numbers, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. In the past, observations of CP violation were confined to neutral . K mesons, but since the early 1990s, a large number of CP-violating processes have been studied in detail in neutral . B mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of . K,D, and . B mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model.In the near future, there will be a transition from the current to a new generation of experiments; thus a review of the status of quark flavor physics is timely. This report is the result of the work of physicists attending the 5th CKM workshop, hosted by the University of Rome "La Sapienza", September 9-13, 2008. It summarizes the results of the current generation of experiments that are about to be completed and it confronts these results with the theoretical understanding of the field which has greatly improved in the past decade.
Bibliographical noteFunding Information:
This work is supported by the Australian Research Council and the Australian Department of Industry Innovation, Science and Research, the Natural Sciences and Engineering Research Council (Canada), the National Science Foundation of China, the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physique des Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Department of Science and Technology of India, the Istituto Nazionale di Fisica Nucleare (Italy), the Ministry of Education Culture, Sports, Science, and Technology (Japan), the Japan Society of Promotion of Science, the BK21 program of the Ministry of Education of Korea, the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, the Slovenian Research Agency, Ministerio de Educación y Ciencia (Spain), the Science and Technology Facilities Council (United Kingdom), and the US Department of Energy and National Science Foundation.
Individuals have received support from European Community’s Marie-Curie Research Training Networks under contracts MRTN-CT-2006-035505 (‘Tools and Precision Calculations for Physics Discoveries at Colliders’) and MRTN-CT-2006-035482 (‘FLAVIAnet’), from the National Science Foundation of China (grants 10735080 and 10625525), the DFG Cluster of Excellence ’Origin and Structure of the Universe’ (grant BU 706/2-1), the Japan Society for the Promotion of Science (grant 20244037), and the A. von Humboldt Stiftung, from MICINN, Spain (grant FPA2007-60323), from the ITP at University of Zurich, from the US National Science Foundation (grant PHY-0555304) and Department of Energy (grants DE-FG02-96ER41005 and DE-AC02-07CH11359–Fermi Research Alliance, LLC), and from Generalitat Valenciana (grant PROMETEO/2008/069).