Jingshin Theoretical Physics Symposium in Honor of Professor Ta-You Wu

The following sections are included:

• Foreword

• Preface

• Contents

The following sections are included:

• A Passion for Physics Inspired by Prof. Yao's Lectures on Modern Physics

• Happiest Years

• Pioneer Works on Transuranium Elements — Ph.D. Thesis

• Return to China and Teaching at Peking Univ. — A Beautiful Time Full of Hope

• Struggles to do Research in Wartime China

• Prof. Wu and His Most Talented Students

• Plunging into new Areas of Research in Ann Arbor, Columbia, Ottawa and Buffalo

• A Pioneer Sower of Physics in Taiwan

• A Man with Profound Love of Physics

• References

The following sections are included:

• PAPERS

• MONOGRAPHS AND BOOKS

• WORKS DONE UNDER THE DIRECTION OF WU

First of all I would like to express my heartfelt appreciation of the kind thought of my colleagues in organizing this symposium. It was sixty years ago when I came here as a graduate student. Today is a most happy day for me to come back here and to recall to my friends my fond memory of my experience here that has shaped my career…

I would like to spend a few minutes to comment on Professor Wu's Ph D. thesis. Before I do this, I should express my thanks to Dr. H. H. Hsu of the Los Alarnos Laboratory who had helped me track down the relevant papers…

This year marks the 90th birthday of Professor Ta-You Wu, who is deeply respected by science and education circles on both sides of the Straits. As a colleague in physics on the mainland, I hereby extend my sincere benediction and greetings to Mr. Wu…

The following sections are included:

• Brochure Profile on Ta -You Wu Lecturers
  • 1992 Ta-You Wu Lecturer: Chen Ning Yang
  • 1993 Ta-You Wu Lecturer: Abraham Pais
  • 1994 Ta-You Wu Lecturer: Joseph H. Taylor
  • 1995 Ta-You Wu Lecturer: T. D. Lee
  • 1996 Ta-You Wu Lecturer: Pierre-Gilles de Gennes
  • 1997 Ta-You Wu Lecturer: Paul Ching-Wu Chu

• Concluding Remark

• Footnotes & References

That symmetry dictates interactions, that geometry is at the heart of physics, and that formal beauty plays a role in describing the world are insights that have had a profound effect on current thought.

One of the most entertaining scientific autobiographies is a book called From Immigrant to Inventor, by Michael Pupin. The name Pupin may be seen over the door of the physics laboratory of Columbia University; for the younger physicists of today the name belongs to the building, and the man is forgotten. This is a pity for he was a colorful as well as a great man. He arrived in America from the backwoods of Hungary at the age of 16, and after various adventures became a Columbia professor when he was 34. He was born with a restless curiosity and a fixed determination to master the science of his time…

The vibrational eigenfrequency problem for carbon-60 is solved analytically by fully exploiting the icosahedral symmetry of the molecule. Exact algebraic expressions for the characteristic polynomials of the vibration are obtained by combining two different methods. Our calculation is based on an inter-atomic interaction which consists of four force-constants, two for bond-stretching and two for angle-oscillation.

Using accurate wave functions, we calculate the quantum number "K" for 33 ¹P^o He resonances in the inelastic scattering region (below the N=3 threshold). We found that this K quantum number is remarkably stable for two of the five resonance series. However, in the other three series, K changes greatly from lower members to higher members. A similar calculation is done for 23 ¹P^o resonances below the N=2 threshold. The result is used to explain the source of existing controversy in the classification of helium resonances in the literature. A critical comparison between the most accurate experiment and theory is made.

The following sections are included:

• Heavy and light hole mixing

• Quantum well excitons

• Raman scattering

• Polarization of hot photoluminescence

This is a tutorial review on knot invariants and their construction using the method of statistical mechanics. We begin with brief reviews of the elements of knot theory and relevant results in statistical mechanics. We then show how knot invariants, including those discovered recently, can be obtained by applying techniques used in solving lattice models in lattice statistics. Our approach is based on the consideration of solvable models with strictly local Boltzmann weights. The presentation, which is self-contained and elementary, is intended for a general readership. A table of polynomial invariants for knot and links containing up to six crossings is included in the Appendix.

We develop a field theory for a partially filled Landau level based on composite fermions with a finite vortex core, whose mean-field states are exactly those described by well-tested trial wave functions. Despite non-orthogonality of free composite-fermion states and non-Hermiticity of the mean-field Hamiltonian, a consistent perturbation theory is formulated and the mean-field Fermi sea at half filling is shown to be stable. While low-energy and long-distance physics is the same as in the Chern-Simons fermion theory new physics is expected to show up for larger wave vectors.

We will derive both quaternion and octonion algebras as the Clebsch-Gordan algebras based upon the su(2) Lie algebra by considering angular momentum spaces of spin one and three. If we consider both spin 1 and ½ states, then the same method will lead to the Lie-super algebra osp(1,2). Also, the quantum generalization of the method is discussed on the basis of the quantum group su_q(2).

The following sections are included:

• Introduction

• Quantum-State Tomography

• References

The spin density matrix for particles of arbitrary intrinsic angular momentum is explicitly expressed in terms of directly measurable quantities. The latter are taken to be either expectation values of components of multipole moments, or the relative weights of partial beams split-up by a Stern–Gerlach apparatus according to eigenvalues of dipole projections in several directions.

We introduce a new sum-rule for large-N_c QCD which relates the density of heavy quarkonium states, the state-averaged square of the wavefunction at the origin, and the heavy quark current-current correlator. Focusing on the region of energy just above perturbative threshold, we calculate the correlator by incorporating arbitrarily high orders in the QCD coupling α_s. We use the sum-rule to determine the bottomonium potential using experimentally measured s-wave leptonic widths and compare the result with the potential obtained by direct calculation from the measured s-wave spectrum. We discuss the utility of the sum-rule method for accurate determination of the confining potential.

In the framework of a model in which a single leptonic photon γ_ι has the same coupling to the doublets μν_μ and , there is no cosmological bound on the strength of this coupling.

While internal space-time symmetries of relativistic particles are dictated by the little groups of the Poincaré group, it is possible to construct representations of the little group for massive particles starting from harmonic oscillator wave functions for the quark model. The resulting oscillator wave functions are covariant and can be Lorentz-boosted. It is thus possible to obtain the parton model by boosting the quark model. A review of Wigner's theory of the little groups is given. It is shown that the covariant oscillator wave functions become squeezed as as the system becomes boosted. It is shown also that the Lorentz-squeezed quark distribution exhibits the peculiarities of Feynman's parton model including the lack of coherence in the calculation of cross sections. A historical review of the concept of covariance is given.

The ηπ^- system has been studied in the reaction η^-p → ηπ^-p at 18 GeV/c. A large asymmetry in the angular distribution is observed indicating interference between L-even and L-odd partial waves. The a₂(1320) is observed in the J^PC = 2⁺⁺ wave, as is a broad enhancement between 1.2 and 1.6 GeV/c² in the 1^-+ wave. The observed phase difference between these waves shows that there is phase motion in addition to that due to a₂(1320) decay. The data can be fitted by interference between the a₂(1320) and an exotic 1^-+ resonance with and .

The general decomposition and inner structure of spin connection on the sphere bundle of a compact and oriented Riemannian manifold is given in terms of N orthonormal vectors via Clifford algebra. A detailed discussion of the application of this inner structure to the Gauss-Bonnet-Chern (GBC) theorem shows that the GBC form can be expressed in terms of a smooth vector field and take the form of the δ function . As a result, the curvature is found to be a generalized function under this situation. The topological current of the GBC theorem and its topological structure are discussed also. Furthermore, the Morse theory formula of Euler-Poincaré characteristic has been obtained.

The supersymmetric left-right (SUSYLR) models solve many of the problems of the minimal supersymmetric standard model (MSSM) such as the R-parity and SUSYCP problems. The first one implies that supersymmetry can provide a naturally stable LSP (lightest supersymmetric particle) which can serve as the cold dark matter of the universe. It is then shown that if W_R mass in the TeV range, the SUSYLR models also provide a natural solution to the strong CP problem without the need for an axion. It is therefore argued that the theory just beyond the MSSM is the SUSYLR model. A crucial prediction of the model is the prediction of the electric dipole moment of the neutron of arising from one-loop contribution to the strong CP parameter . Other predictions are a light doubly charged scalar boson and its fermionic superpartner with masses in the few hundred GeV range.

We calculate the lifetime (or decay length) dilation of an unstable particle in flight traveling with constant linear acceleration, where "constant linear acceleration" has been redefined in relativistically consistent terms. These predictions are made using two existing physical theories of non-inertial frames and could easily be tested using the linear accelerators available today. The physical theories are based on the principle of "limiting four-dimensional symmetry," which requires the transformations to have the symmetry property of the Lorentz group in the limiting case where the acceleration goes to zero. The validation of either of these theories would allow an exact calculation of the result of the famous "clock paradox" of special relativity.

We suggest that naive perturbation theory up to 0(α_s³) underestimates the theoretical prediction for . We use Padé Summation (PS) and find α_s(M_z) = .313(9). Using the new 4-loop QCD β-function, we find α_s(M_z) = .1172(11) in agreement with recent values.

Physics involving phase transition between hadronic matter and quark gluon plasma is discussed. The necessary condition for the formation of quark matter phase manifest that such kind of new phase can be realized in relativistic heavy ion collisions. The difference on energy density between hadronic matter and quark matter is estimated. The way to estimate the energy density in relativistic heavy ion collisions is proposed. Two possible signatures of appearance of quark matter in relativistic heavy ion collisions are discussed.

In this paper we review the current status of cosmological theory. First a brief discussion of Friedmann model and classical observations is presented. Next the events of the early Universe from a fraction of a second to the pressent are discussed from the point of view of high temperature thermodynamics. The most important phenomena in this phase are pair creation of particles and nuclear equilibrium at temperatures 10⁹ K and above. When the temperature drops, nuclear equilibrium will freeze out, resulting in the synthesis of helium and some light elements. Likewise pairs of particles will annihilate at lower temperatures but some relic particles may remain intact today. So far the theory seems to be on solid ground. However, there are many unanswered questions which force one to make certain drastic assumptions, such as the existence of dark (invisible) matter. One is also forced to retrace the evolution of the Universe back in time to 10^-36 second, during which quantum effects of gravity become important. This then leads to the Inflationary Theory. This theory is still under development. Scanty data exist to support or to refute the theory. The origin of our Universe – the ultimate frontier in astrophysics and a Pandora Box – is now open for exploration.

The following sections are included:

• Introduction

• Physical Time in Accelerated Frames

• Physical Implications of the Principle of Limiting 4-Dimensional Symmetry

• Generalized Møller-Wu-Lee Transformation

• Minimal Generalization of Lorentz Transformations—the Wu Transformation

• Exact Rotational Transformations Based on Limiting 4-Dimensional Symmetry

• Problems of Physical Time in Non-inertial Frames and Particle Kinematics

• Appendix. Rotational Transformation with Constant Angular Accelerations

• References

Based on the principle of relativity and the experimental fact that light can propagate in vacuum, the speed of light is shown to be absolute. It is further concluded that any signal that can propagate in vacuum must also have an absolute speed equal to that of light.

We have used the Classtalk system, a classroom communication system, and the Web to augment large classroom teaching. With the Classtalk system, the usual mode of operation is to have several question/answer sessions interspersed with the lecture. To promote the participation of the entire class, during these sessions, students are encouraged to interact with neighbors. We refer a question/answer session as an "interactive quiz session", or an IQ-session. In this manner we engage the attention of the whole class, so that the entire class may be more involved in the classroom experience. The Classtalk system is a useful tool to capture and hold the students' attention. Students like the statistical plots of feedback with anonymity. We are developing a collection of IQ questions for using the system. We are pleased with the results. On the Web, we make use of the Comment Board and the Instructor's Comment column. Among other things, students get help through email and through the Comment Board on the Web. From the instructor's point of view, what is communicated to the individual student, can be made available to all students in an anonymous manner using the Web. This is an important time saving feature, especially when teaching a large class.

The following sections are included:

• Appendix A. A Chronology of Ta-You Wu's Life and Career

• Appendix B. Data of "Elementary Particles" (1998) for Comparison with Those on pp. 82-83 in "Innovation in Physics"

• Appendix C. Captions and Credits of Photos