文摘
Over the past two decades, meson photo- and electroproduction data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even non-existent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledge in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a state-of-the-art meson-beam facility needs to be constructed. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility. Communicated by U.-G. Mei?nerWilliam J. Briscoe received his PhD from the Catholic University of America (CUA) in 1978 (M.S. Northeastern 1972, B.A. CUA 1970). He was an assistant research professor for four years at UCLA. He came to the George Washington University in 1982 as an assistant professor, was promoted to associate professor in 1986 and professor in 1998. Currently, he is director of the GW/JLab Data Analysis Center and director of the GW Institute for Nuclear Studies. He has held guest and visiting scientist positions at several international laboratories.Michael D?ring received his PhD in 2007 from the Universitat de València, Spain. He held postdoctoral research positions at the Research Center Jülich, Germany (2007-010) and at the HISKP/University of Bonn, Germany (2010-014). He has been an assistant professor at The George Washington University since 2014. He received an NSF Career award in 2015. His research interests cover baryon spectroscopy and the phenomenology of photoproduction reactions, as well as finite–volume effects in Lattice QCD simulations.Helmut Haberzettl is a theoretical nuclear and particle physicist. He received his doctoral degree from the University of Bonn, Germany, in 1979. He worked as a research associate at the University of South Africa, in Pretoria, and the University of Bonn. In 1988, he joined the faculty of The George Washington University in Washington, DC. He has held numerous visiting positions, mainly in Germany. His main areas of research include interactions of mesons and nucleons at intermediate energies, and the interactions of hadrons and photons as described by microscopic reaction theories.D. Mark Manley is an experimentalist and phenomenologist in hadronic physics. He received the doctoral degree from the University of Wyoming in 1981 and worked as a postdoctoral research associate at Virginia Polytechnic Institute and State University and Lawrence Livermore National Laboratory before joining the Physics Department at Kent State University in 1986. He has been a full professor there since 1997. His recent research has focused on meson photoproduction and multichannel partial-wave analyses.Megumi Naruki is an associate professor in the Department of Physics at Kyoto University. After obtaining her PhD at Kyoto University in 2006, she served as an assistant professor at KEK and conducted the first experiment to search for the Θ + pentaquark at the J-PARC Hadron Facility. Prior work experience includes the dilepton measurements at 12 GeV pA interactions. Her primary research activity is experimental hadron physics, especially baryon spectroscopy using intense meson beams.Igor I. Strakovsky is an experimentalist and phenomenologist in hadronic physics. He received the doctoral degree from the Petersburg Nuclear Physics Institute in 1969 and worked as an associate research scientist and research scientist at PNPI before joining the Physics Department at The GeorgeWashington University in 1997. He has been a full research professor there since 2009. He is the primary person keeping up the much-referenced SAID database, providing a support of experimental programs associated with analyses of preliminary experimental data and help in the planning of new measurements. His recent research has focused on multichannel partial-wave analyses.Eric Swanson is a professor of physics at the University of Pittsburgh specializing in the theory of hadronic structure. He obtained his PhD from the University of Toronto in 1991 and subsequently spent three years at MIT and six years in North Carolina before moving to Pittsburgh. He has published in theoretical hadronic physics, condensed matter physics, and biophysics and authored the book, “Science and Society- He is a founder of the APS Topical Group on Hadronic Physics and has been a visiting scientist at TRIUMF, Oxford, JLab, and LANL.