Eulerian parametrization of Wigner’s little groups and gauge transformations in terms of rotations in two‐component spinors

1986 ◽  
Vol 27 (9) ◽  
pp. 2228-2235 ◽  
Author(s):  
D. Han ◽  
Y. S. Kim ◽  
D. Son
Keyword(s):  
Gauge Transformations ◽  
Two Component ◽  
Wigner’S Little Groups

scholarly journals Do Small-Mass Neutrinos Participate in Gauge Transformations?

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Y. S. Kim ◽  
G. Q. Maguire ◽  
M. E. Noz
Keyword(s):  
Small Mass ◽  
Large Momentum ◽  
Mass Limit ◽  
Finite Mass ◽  
Gauge Invariant ◽  
Gauge Transformations ◽  
Zero Mass ◽  
Massive Neutrinos ◽  
Wigner’S Little Groups ◽  
Dirac Spinors

Neutrino oscillation experiments presently suggest that neutrinos have a small but finite mass. If neutrinos have mass, there should be a Lorentz frame in which they can be brought to rest. This paper discusses how Wigner’s little groups can be used to distinguish between massive and massless particles. We derive a representation of theSL(2,c)group which separates out the two sets of spinors: one set is gauge dependent and the other set is gauge invariant and represents polarized neutrinos. We show that a similar calculation can be done for the Dirac equation. In the large-momentum/zero-mass limit, the Dirac spinors can be separated into large and small components. The large components are gauge invariant, while the small components are not. These small components represent spin-1/2non-zero-mass particles. If we renormalize the large components, these gauge invariant spinors represent the polarization of neutrinos. Massive neutrinos cannot be invariant under gauge transformations.

THE QUANTUM TUNNELLING BETWEEN TWO-COMPONENT BOSE–EINSTEIN CONDENSATES IN A DOUBLE-WELL CONFIGURATION

2005 ◽  
Vol 19 (20) ◽  
pp. 3285-3292
Author(s):  
GUO-FENG ZHANG
Keyword(s):  
Berry Phase ◽  
Time Dependent ◽  
Hamilton Operator ◽  
Gauge Transformations ◽  
Quantum Tunnelling ◽  
Interacting Species ◽  
Particle Population ◽  
Two Component ◽  
Population Imbalance ◽  
Bose Einstein

We examine in terms of exact solutions of the time-dependent Schrödinger equation, the quantum tunnelling process in Bose–Einstein condensates of two interacting species trapped in a double well configuration. Based on the two series of time-dependent SU(2) gauge transformations, we diagonalize the Hamilton operator and obtain analytic time-evolution formulas of the population imbalance and the berry phase. The particle population imbalance [Formula: see text] of species A between the two wells is studied analytically.

Spectroscopic Observations of Visual Double Stars

1965 ◽  
Vol 5 ◽  
pp. 109-111
Author(s):  
Frederick R. West
Keyword(s):  
Radial Velocity ◽  
High Dispersion ◽  
Velocity Difference ◽  
Spectrograph Slit ◽  
Spectroscopic Observations ◽  
Double Stars ◽  
Visual Double Stars ◽  
Relative Orbit ◽  
Two Component ◽  
Star Images

There are certain visual double stars which, when close to a node of their relative orbit, should have enough radial velocity difference (10-20 km/s) that the spectra of the two component stars will appear resolved on high-dispersion spectrograms (5 Å/mm or less) obtainable by use of modern coudé and solar spectrographs on bright stars. Both star images are then recorded simultaneously on the spectrograph slit, so that two stellar components will appear on each spectrogram.

A technique for protecting delicate specimens during processing

1989 ◽  
Vol 47 ◽  
pp. 982-983
Author(s):  
R.J. Mount ◽  
R.V. Harrison
Keyword(s):  
Basilar Membrane ◽  
Low Cost ◽  
Organ Of Corti ◽  
Region Of Interest ◽  
Sensory Epithelium ◽  
Physical Damage ◽  
Air Drying ◽  
Specimen Handling ◽  
Two Component

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.

Fifth virial coefficient of a two-component mixture of hard discs

1997 ◽  
Vol 90 (4) ◽  
pp. 679-681
Author(s):  
F. SAIJA ◽  
G. FIUMARA ◽  
P.V. GIAQUINTA
Keyword(s):  
Virial Coefficient ◽  
Component Mixture ◽  
Two Component

Phase transitions and shapes of two component membranes and vesicles II : weak segregation limit

1994 ◽  
Vol 4 (8) ◽  
pp. 1333-1362 ◽  
Author(s):  
Takashi Taniguchi ◽  
Kyozi Kawasaki ◽  
David Andelman ◽  
Toshihiro Kawakatsu
Keyword(s):  
Phase Transitions ◽  
Two Component

Strongly coupled nonneutral plasmas : Equilibrium and relaxation in two-component plasmas in Penning-Malmberg trap

2000 ◽  
Vol 10 (PR5) ◽  
pp. Pr5-271-Pr5-274
Author(s):  
H. Totsuji ◽  
K. Tsuruta ◽  
C. Totsuji ◽  
K. Nakano ◽  
T. Kishimoto ◽  
...  
Keyword(s):  
Strongly Coupled ◽  
Nonneutral Plasmas ◽  
Two Component
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