Relativistic Quantum Invariance

This book describes the invariant nature of the relativistic quantum field theories utilizing the idea of interpolating the instant form dynamics and the light-front dynamics. While the light-front dynamics (LFD) based on the light-front time was proposed by Dirac in 1949, there has not yet been a salient review on the connection between the LFD and the instant form dynamics (IFD) based on the ordinary time. By reviewing the connection between LFD and IFD using the idea of interpolating the two different forms of the relativistic dynamics, one can learn the distinguished features of each form and how one may utilize those distinguished features in solving the complicated relativistic quantum field theoretic problems more effectively. With the ongoing 12-GeV Jefferson Lab experiments, the internal structures of the nucleon and nuclei are vigorously investigated in particular using the physical observables defined in the LFD rather than in the IFD. This book offers a clear demonstration on why and how the LFD is more advantageous than the IFD for the study of hadron physics, illustrating the differences and similarities between these two distinguished forms of the dynamics. It aims at presenting the basic first-hand knowledge of the relativistic quantum field theories, describing why and how the different forms of dynamics (e.g., IFD and LFD) can emerge in them, connecting the IFD and the LFD using the idea of the interpolation, and demonstrating explicit examples of the interpolation in quantum electrodynamics and other field theories. While the level of presentation is planned mainly for the advanced undergraduate students and the beginning graduate students, the topics of the interpolation between the IFD and the LFD are innovative enough for even the experts in the field to appreciate its usefulness.

Professor Chueng-Ryong Ji at Department of Physics, North Carolina State University (NCSU), joined the faculty in 1987 and served as the director of the Graduate Program for 2013-2015. He is a fellow and outstanding referee of American Physical Society (APS) and serves as the chair of the International Light Cone Advisory Committee. His recent research work with the Jefferson Lab Angular Momentum (JAM) collaborators including his graduate student published in Phys. Rev. Lett.121,152001(2018) “First Monte Carlo Global QCD Analysis of Pion Parton Distributions” was highlighted with a short summary (Synopsis) on the APS website as well as the IOP’s “Physics World.” Professor Ji pioneered the idea of connecting the instant form dynamics and the light-front dynamics and applied this idea in solving relativistic bound state and scattering problems. His seminal work with his graduate students and visiting scholar “Interpolating quantum electrodynamics between instant and front forms” was published in Phys. Rev. D98, 036017(2018). Professor Ji wrote the book entitled “Pedestrian Approach to Particle Physics” as the first monograph published by the Asia Pacific Center for Theoretical Physics in 2007. Before he joined the faculty at NCSU, he was a visiting scholar at the theory group of the Stanford Linear Accelerator Center (SLAC) for 1982-84, a postdoctoral fellow at Department of Physics, Stanford University, for 1984-86, and a research associate at Brooklyn College of the City University of New York in for 1986-97. Professor Ji received his Ph.D. in 1982 from Korea Advanced Institute of Science and Technology and his Bachelor’s degree with Honor in 1976 from Seoul National University.