Physical Degrees of Freedom for Gauge Fields and the Issue of Spin

The conflict between the physical degrees of freedom of gauge bosons and the Lorentz group irreps naturally used to describe their couplings to matter fields are illustrated and discussed, and applied to issues of linear and angular momentum.Comment: 10pp., no figures, to appear in PACSpin2011 (Cairns, 20-24 June, 2011) conf. proc. (AIP

No Strings Attached: Potential vs. Interaction Energy In QCD

In infrared-stable fixed-point field theories, the interaction energy of a test particle is proportional to the non-relativistic (heavy source) coordinate-space potential derived from the field strength produced by that source. This is no longer true in ultraviolet-stable fixed-point field theories (UVSFPFT) as they may not have a finite infrared fixed point. This leads to the possibility that UVSFPFTs may have quite conventional field strength distributions despite the unusual spatial dependence expected for the interaction energy.Comment: 4 pages, LaTeX, no figures, uses sprocl.sty, to appear in the Proceedings of the Int'l Workshop on Quark Confinement and the Hadron Spectrum II (June 26-29, 1996, Villa Olmo, Como, Italy), ed. N. Brambill

Origin of spontaneous violation of the Lorentz symmetry: Vortices in the cosmos

By carefully studying the (1,0)+(0,1) representation space for massive particles we point to the existence of certain inherent tachyonic dispersion relations: E^2= p^2-m^2. We put forward an interpretation that exploits these ``negative mass squared'' solutions; rotational invariance is spontaneously broken. Relevance of these results to the vortices in the cosmos is pointed out. NOTE: Just as "negative energy solutions'' of Dirac equation are re-interpreted as antiparticles, similarly the possibility exists for re-interpreting the tachyonic dispersion relations of all (j,0)+(0,j) representation spaces via spontaneous Lorentz symmetry breaking. In Mod. Phys. Lett. A8:2623-2630,1993 we exhibited this explicitly for the j=1 representation space. The interest in this old subject has grown markedly in recent years as is evident from numerous theoretical and phenomenological works on the subject. With this observation, we make this replacement of our paper fourteen years after its initial publication. The Abstract and main text remain unaltered. The title is changed to reflect the underlying physics more closely.Comment: This is an exact copy of the published paper with an extended bibliography and a revised title. A brief note is added to point out a systematic way to spontaneously break Lorentz symmetr

Pion LINAC as an Energy-Tagged Neutrino Source

The energy spectrum and flux of neutrinos from a linear pion accelerator are calculated analytically under the assumption of a uniform accelerating gradient. The energy of a neutrino from this source reacting in a detector can be determined from timing and event position information.Comment: 16 pages, 4 figures. Replacement of Section II.D and minor corrections elsewhere. The basic point and conclusions of the paper are unchanged. Phys. Rev. ST Accel. Beams 11,124701 (2008); Erratum submitte