119082127
Wigner's Photons
If Einstein's photon is $E = cp = \hbar\omega$, Wigner's photon is its helicity which is a Lorentz-invariant concept coming from the E(2)-like little group for massless particles. In addition, the E(2)-like little group has two translation-like degrees of freedom. What happens to them? They are associated with the gauge degree of freedom. Since the physics of polarized light waves can be formulated within the framework of the Lorentz group, it is now possible to use polarization experiments to study the E(2)-like little group in terms of quantities that can be measured in laboratories.
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.
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.
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,...
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.
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.
18064237
The effect of kaon condensation on quark-antiquark condensate in dense matter
Abstract Assuming that at sufficiently high densities the constituent quarks become relevant degrees of freedom, we study within the framework of a chiral quark model the influence of s -wave K − condensation on the quark–antiquark condensates. We find that, in linear density approximation, the presence of a K − condensate quenches the u ¯ u condensate, but that the d ¯ d condensate remains unaffected up to the chiral order under consideration. We discuss the implication of the suppressed u ¯ u condensate for flavor-dependent chiral symmetry restoration in dense matter.
56009963
Single bunch collective effects in PLS storage ring
The single bunch collective effects such as the bunch lengthening due to the potential well distortion and the microwave instability which also increases the energy spread, the transverse head-tail instability, and the transverse strong head-tail instability are investigated in the Pohang Light Source storage ring. The threshold current and the Chao-Gareyte scaling factor of the bunch lengthening, the longitudinal broadband impedance, and the transverse impedance have been measured and compared with the ZAP code results.
118715122
Physics from Tristan
The TRISTAN e + e − storage ring has delivered a total of about 60 pb−1 to each of the three general purpose solenoidal detectors: AMY, TOPAZ and VENUS. The center-of-mass energy range, between 50 and 64 GeV, is where interference effects between the virtual photon and Z0 mediators of the annihilation process are largest. Experiments at TRISTAN study the electroweak interactions, QCD, and search for new phenomena. Among the reported results are: measurements of R; the observation of forward-backward charge asymmetries for e+e− → lepton pairs, \(e^ + e^ - \to b\bar b\), and \(e^ + e^ - \to q\bar q\); limits on lepton compositeness; determinations of \(\Lambda _{\overline {MS} }\); measurements of various multihadron event properties; evidence for differences between quark and gluon jets; the demonstration of the running of αs and the existence of the triple-gluon coupling; and searches for a variety of new particles. This report describes a few selected results from the AMY experiment.
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.
119304627
The evolution of FTK, a real-time tracker for hadron collider experiments
We describe the architecture evolution of the highly-parallel dedicated processor FTK, which is driven by the simulation of LHC events at high luminosity (1034 cm-2 s-1). FTK is able to provide precise on-line track reconstruction for future hadronic collider experiments. The processor, organized in a two-tiered pipelined architecture, execute very fast algorithms based on the use of a large bank of pre-stored patterns of trajectory points (first tier) in combination with full resolution track fitting to refine pattern recognition and to determine off-line quality track parameters. We describe here how the high luminosity simulation results have produced a new organization of the hardware inside the FTK processor core.