126020793
REPRESENTATIONS OF THE TWO-DIMENSIONAL EUCLIDEAN GROUP FOR MASSLESS PARTICLES WITH INTEGER SPIN
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.
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.
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.
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.
119495662
Direct radiative recombination of electrons with atomic ions: Cross sections and rate coefficients
Simple expressions are obtained which permit systematic estimates of the rate coefficients for direct radiative recombination (DRR) of fast electrons with atomic ions of various ionic species. The analysis utilizes a set of cross sections obtained through numerical calculations combined with the use of an interpolation scheme to smoothly connect reduced cross sections (apart from normalizations) of the bremsstrahlung tip region and the low-lying DRR region. It is shown that these numerical cross sections can be reproduced by the predictions of a modified semiclassical Kramers formula with an appropriate effective charge Z/sub eff/, which is larger than the effective charge which reproduces the energy levels of the states into which capture occurs. In accord with this modified Kramers formula, the numerically obtained total cross sections are shown to scale with Z/sub eff//sup 2//K for each isoelectronic sequence, and with a parameter (n/sub 0/)/sub eff/ which characterizes each isoelectronic sequence. Using these scaling properties, simple analytic expressions are obtained for recombination rate coefficients, for the rate of electron kinetic-energy loss, and for the rate of radiated power loss, assuming a classical Maxwell-Boltzmann thermal distribution of continuum electrons.
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.
3194304
Kaon Condensation and Enforced Charge Neutrality of the Color-Flavor Locked Phase
We investigate the influence of charged kaon condensation in hadronic sector on the formation of the electron-free charge neutral quark matter of equipartition of three light flavors, i.e., a phenomenon called ``enforced electrical neutrality" of the color-flavor locked (CFL) phase. We employ the chiral quark model which is assumed to be applicable, "bottom-up," toward chiral restoration while accessible to kaon condensation in the hadronic sector. Approaching "bottom-up" the high density regime is more appropriate in addressing the properties of compact stars than approaching "top-down" from asymptotic QCD. It turns out that the presence of hadronic kaon condensation makes the electron-free charge-neutral CFL phase energetically more favorable with a relatively small color-superconducting gap $\Delta_0\sim 20$ MeV compared to $\Delta_0\sim 70$ MeV required in the absence of such kaon condensation.
51814291
Design study on standing-wave linear accelerator
A compact standing-wave linac has been designed using S-band microwaves for medical and industrial applications. It uses a bi-periodic structure with constant impedance. It consists of a buncher section with three-cells and on-axis coupled cavities with nine-cells. The total length is 740.0 mm including the electron gun. Using SUPERFISH, HFSS and PARMELA codes, it is capable to deliver 4.5 MeV electron beams with pulsed microwaves of 4.8 MW at 2,856 MHz. In this paper, we present the detailed design studies on a compact S-band standing-wave linac.
119289779
M(T2)-assisted on-shell reconstruction of missing momenta and its application to spin measurement at the LHC
We propose a scheme to assign a 4-momentum to each WIMP in new physics event producing a pair of mother particles each of which decays to an invisible weakly interacting massive particle (WIMP) plus some visible particle(s). The transverse components are given by the value that determines the event variable M{sub T2}, while the longitudinal component is determined by the on-shell condition on the mother particle. Although it does not give the true WIMP momentum in general, this M{sub T2}-assisted on-shell reconstruction of missing momenta provides kinematic variables well correlated to the true WIMP momentum and thus can be useful for an experimental determination of new particle properties. We apply this scheme to some processes to measure the mother particle spin and find that spin determination is possible even without good knowledge of the new particle masses.