117941616
Lorentz Group derivable from Polarization Optics 1
The Lorentz group is the fundamental language for space-time symmetries of relativistic particles. This group can these days be derived from the symmetries observed in other branches of physics. It is shown that this group can be derived from optical filters. The group O(2,1) is appropriate for attenuation filters, while the O(3) group describes phase-shift filters. The combined operation leads to a two-by-two representation of the six-parameter Lorentz group. It is shown also that the bilinear representation of this group is the natural language for the polarization optics. The Lorentz group serves useful purposes in many branches of physics. In this note, we would like to show that the bilinear representation of the six-parameter Lorentz group [1] is the natural language for polarization of light waves. In studying polarized light propagating along the z direction, the traditional approach is to consider the x and y components of the electric fields. Their amplitude ratio and the phase difference determine the degree of polarization. Thus, we can change the polarization either by adjusting the amplitudes, by changing the relative phase shift, or both. For convenience, we call the optical device which changes amplitudes an “attenuator,” and the device which changes the relative phase a “phase shifter.” Let us write the electric field vector as
14939249
Coupled Harmonic Oscillators and Feynman's Rest of the Universe
According to Feynman, the universe consists of two parts - the system in which we are interested and the rest of the universe which our measurement process does not reach. Feynman then formulates the density matrix in terms of the observable world and the rest of the universe. It is shown that coupled harmonic oscillators can serve as an illustrative example for Feynman's ``rest of the universe.'' It is pointed out that this simple example has far-reaching consequences in many branches of physics, including statistical mechanics, measurement theory, information theory, thermo-field dynamics, quantum optics, and relativistic quantum mechanics. It is shown that our ignorance of the rest of the universe increases the uncertainty and entropy in the system in which we are interested.
73571003
Time separation as a hidden variable to the Copenhagen school of quantum mechanics
The Bohr radius is a space‐like separation between the proton and electron in the hydrogen atom. According to the Copenhagen school of quantum mechanics, the proton is sitting in the absolute Lorentz frame. If this hydrogen atom is observed from a different Lorentz frame, there is a time‐like separation linearly mixed with the Bohr radius. Indeed, the time‐separation is one of the essential variables in high‐energy hadronic physics where the hadron is a bound state of the quarks, while thoroughly hidden in the present form of quantum mechanics. It will be concluded that this variable is hidden in Feynman’s rest of the universe. It is noted first that Feynman’s Lorentz‐invariant differential equation for the bound‐state quarks has a set of solutions which describe all essential features of hadronic physics. These solutions explicitly depend on the time separation between the quarks. This set also forms the mathematical basis for two‐mode squeezed states in quantum optics, where both photons are observable,...
668406
Quantization of electromagnetic fields in a circular cylindrical cavity
We present a quantization procedure for the electromagnetic field in a circular cylindrical cavity with perfectly conducting walls, which is based on the decomposition of the field. A new decomposition procedure is proposed; all vector mode functions satisfying the boundary conditions are obtained with the help of this decomposition. After expanding the quantized field in terms of the vector mode functions, it is possible to derive the Hamiltonian for this quantized system.
1673726
Symmetries Shared by the Poincaré Group and the Poincaré Sphere
Henri Poincare formulated the mathematics of Lorentz transformations, known as the Poincare group. He also formulated the Poincare sphere for polarization optics. It is shown that these two mathematical instruments can be derived from the two-by-two representations of the Lorentz group. Wigner’s little groups for internal space-time symmetries are studied in detail. While the particle mass is a Lorentz-invariant quantity, it is shown to be possible to address its variations in terms of the decoherence mechanism in polarization optics.
1320799
Wigner rotations and Iwasawa decompositions in polarization optics.
Wigner rotations and Iwasawa decompositions are manifestations of the internal space-time symmetries of massive and massless particles, respectively. It is shown to be possible to produce combinations of optical filters which exhibit transformations corresponding to Wigner rotations and Iwasawa decompositions. This is possible because the combined effects of rotation, phase-shift, and attenuation filters lead to transformation matrices of the six-parameter Lorentz group applicable to Jones vectors and Stokes parameters for polarized light waves. The symmetry transformations in special relativity lead to a set of experiments which can be performed in optics laboratories.
5924990
BARYON DENSITY AND THE DILATED CHIRAL QUARK MODEL
We calculate perturbatively the effect of density on hadronic properties using the chiral quark model implemented by the QCD trace anomaly to see the possibility of constructing a Lorentz-invariant Lagrangian at finite density. We calculate the density-dependent masses of the constituent quark, the scalar field, and the pion in one-loop order using the technique of thermofield dynamics. In the chiral limit, the pion remains massless at finite density. It is found that the tadpole-type corrections lead to decreasing masses with increasing baryon density, while the radiative corrections induce Lorentz-symmetry-breaking terms. We found in the large N{sub c} limit with large scalar mass that the tadpoles dominate and the mean-field approximation is reliable, giving rise to a Lorentz-invariant Lagrangian with masses decreasing as the baryon density increases. {copyright} {ital 1997} {ital The American Physical Society}
73541758
PLS RF system operation during the commissioning
The storage ring of the Pohang Light Source (PLS) is designed to store 100s mA of 2 GeV electrons injected from the full energy linear accelerator. To compensate for the synchrotron radiation loss three RF cavities were installed in one of the straight sections powered by three 60 kW-TV transmitters independently. Phase and amplitude are controlled by the separate low level systems. During the commissioning, since the beam lifetime is limited by the vacuum pressure, various accelerating voltages were set to investigate the system characteristics. Even one cavity is enough to store 100 mA of beam, whereas the vacuum-limited lifetime is few minutes at 1 mTorr. The cavity HOM-induced multi-bunch instabilities were observed at certain condition and cured to some extent by shifting phase and water temperature. General description of RF system performance and trouble-shoots during the commissioning are presented.
8523168
Fixed-Point Analysis of the Low-Energy Constants in the Pion-Nucleon Chiral Lagrangian
In the framework of heavy-baryon chiral perturbation theory, we investigate the fixed point structure of renormalization group equations (RGE) for the ratios of the renormalized low energy constants (LECs) that feature in the pion-nucleon chiral Lagrangian. The ratios of the LECs deduced from our RGE analysis are found to be in semi-quantitative agreement with those obtained from direct fit to the experimental data. The naturalness of this agreement is discussed using a simple dimensional analysis combined with Wilsonian RGEs.
121020837
Observation of zeros and amplification of quadrupole-matrix-element contributions to photoelectron angular distributions
14653529
Vector susceptibility and chiral phase transition in AdS/QCD Models
We calculated the vector susceptibilitiy in holographic QCD models to study QCD chiral/deconfinemnt phase transition. We found that the vector susceptibility obtained in this work agrees with the results from various model calculations and lattice QCD. Just above Tc χV from QCD calculations [12, 17, 18] saturate to the value of the free-quark gas faster than what we obtain in this work. We also discuss the chiral phase transitions in AdS/QCD models.