120854919
Covariant harmonic oscillators and the parton picture
It is shown that the covariant-harmonic-oscillator wave function exhibits the peculiarities of the Feynman parton picture in the infinite-momentum frame.
119689322
Internal Space-time Symmetries according to Einstein, Wigner, Dirac, and Feynman
When Einstein formulated his special relativity in 1905, he established the law of Lorentz transformations for point particles. It is now known that particles have internal space-time structures. Particles, such as photons and electrons, have spin variables. Protons and other hadrons are regarded as bound states of more fundamental particles called quarks which have their internal variables. It is still one of the most outstanding problems whether these internal spacetime variables are transformed according to Einstein’s law of Lorentz transformations. It is noted that Wigner, Dirac, and Feynman made important contributions to this problem. By integrating their efforts, it is then shown possible to construct a picture of the internal spacetime symmetry consistent with Einstein’s Lorentz covariance. email: yskim@physics.umd.edu email: marilyne.noz@gmail.com 1
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.
40702960
Covariant phase-space representation and overlapping distribution functions.
The Lorentz deformation property of the phase-space distribution function is studied for harmonic oscillators. The overlap effect of two distribution functions is discussed in detail. It is shown that the Lorentz deformation of the phase-space distribution is responsible for the polynomial cutoff behavior of the proton form factor in the harmonic-oscillator quark model.
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.
8670554
Eugene Wigner and Translational Symmetries
As Einstein's $E = mc^{2}$ unifies the energy-momentum relation for massive and massless particles, Wigner's little group unifies their internal space-time symmetries. It is pointed out that translational symmetries play essential roles both in formulating the problem, and in deriving the conclusions. The input translational symmetry is the space-time translation, and the output translational symmetry is built in the E(2)-like little group for massless particles. The translational degrees of freedom in this little group are gauge degrees of freedom. It should be noted that a number of condensed matter physicists played important supporting and supplementary roles in Wigner's unification of internal space-time symmetries of massive and massless particles.
5119942
Measuring superparticle masses at hadron collider using the transverse mass kink
We present a detailed study of the collider observable mT2 applied for pair-produced superparticles decaying to visible particles and a pair of invisible lightest supersymmetric particles (LSPs). Analytic expressions of the maximum of mT2 over all events (mT2max) are derived. It is noticed that if the decay product of each superparticle involves more than one visible particle, mT2max being a function of the trial LSP mass mχ has a kink structure at mχ = true LSP mass, which can be used to determine the mother superparticle mass and the LSP mass simultaneously. To see how well mT2max can be constructed from collider data, a Monte-Carlo analysis of the gluino mT2 is performed for some superparticle spectra.
59372197
BEAM SIMULATION OF SQQ INJECTION SYSTEM IN KIRAMS-30 CYCLOTRON ∗
The injection system of KIRAMS-30 cyclotron consists of a doublegap buncher,an SQQ, and a spiral inflector. Initial beam with 100 mmmrad has been generated by random Gaussian function in the transverse plane and random uniform function in the longitudinal direction. Using the 3D electric and magnetic fields of a buncher, SQQ, inflector, and return-yoke bore, the characteristics of the beam injected into the KIRAMS-30 cyclotron’s central region has been obtained. This paper presents the results of its beam characteristics and parameters of each beam element.
11157984
Growth time of the longitudinal coupled bunch mode beam instability at the Duke FEL facility
To determine the required power of an amplifier for the longitudinal feedback (LFB) system, the growth time of the strongest longitudinal coupled bunch mode instability (CBMI) in the Duke storage ring should be measured in advance. In 2005, we measured strength of the strongest longitudinal beam instability in the Duke storage ring with four and eight symmetrically filled buckets. By analyzing measured data, the growth time of the strongest dipole mode of the longitudinal CBMI in the Duke storage ring can be estimated. At a beam energy of 274 MeV, the growth time is about 0.365 ms for a total stored beam current of 160 mA. From the measured growth time, we estimated the required power of the amplifier for the LFB system. To damp all harmful longitudinal CBMIs with an energy deviation of 0.1 % (rms) within its growth time of 0.365 ms, we have to supply about HOW (rms) to an LFB kicker whose a central frequency is 937.3875 MHz. In this paper, we describe the growth time of the longitudinal CBMI at the Duke storage ring and the estimation of the required power for the LFB system to damp all CBMIs within 0.365 ms.
122988282
A method of closed orbit correction under constraint conditions
We have developed the correction algorithm of the closed orbit distortion (COD) under the constraint condition where beam positions at particular points are not changed. The new algorithm is based on the modified PSINOM algorithm including the regularization process in order to avoid the inversion problem of the ill-posed response matrices. We have confirmed that the COD is well corrected with no orbit leak in the simulation and is in good agreement with the experiment.
9733106
Microlensing Detections of Planets in Binary Stellar Systems
We demonstrate that microlensing can be used for detecting planets in binary stellar systems. This is possible because in the geometry of planetary binary systems, in which the planet orbits one of the binary components and the other binary star is located at a large distance, both planet and secondary companion produce perturbations in a common region around the planet-hosting binary star, and thus the signatures of both planet and binary companion can be detected in the light curves of high-magnification lensing events. We find that identifying planets in binary systems is optimized when the secondary is located within a certain range that depends on the type of the planet. The proposed method can detect planets with masses down to one-tenth of the Jupiter mass in binaries with separations 100 AU. These ranges of planet masses and binary separations are not covered by other methods, and thus microlensing would be able to make the planetary binary sample richer.