3 research outputs found
Lorentz Invariance and Origin of Symmetries
In this letter we reconsider the role of Lorentz invariance in the dynamical
generation of the observed internal symmetries. We argue that, generally,
Lorentz invariance can only be imposed in the sense that all Lorentz
non-invariant effects caused by the spontaneous breakdown of Lorentz symmetry
are physically unobservable. Remarkably, the application of this principle to
the most general relativistically invariant Lagrangian, with arbitrary
couplings for all the fields involved, leads by itself to the appearance of a
symmetry and, what is more, to the massless vector fields gauging this symmetry
in both Abelian and non-Abelian cases. In contrast, purely global symmetries
are only generated as accidental consequences of the gauge symmetry.Comment: 10 page LaTeX fil
Spontaneous Lorentz Violation via QED with Non-Exact Gauge Invariance
We reconsider an alternative theory of the QED with the photon as a massless
vector Nambu-Goldstone boson and show that the underlying spontaneous Lorentz
violation caused by the vector field vacuum expectation value, while being
superficial in gauge invariant theory, becomes physically significant in the
QED with a tiny gauge non-invariance. This leads, through special dispersion
relations appearing for charged fermions, to a new class of phenomena which
could be of distinctive observational interest in particle physics and
astrophysics. They include a significant change in the GZK cutoff for UHE
cosmic-ray nucleons, stability of high-energy pions and W bosons, modification
of nucleon beta decays, and some others.Comment: 15 pages, to appear in Eur.Phys.J.
Standard Model with Partial Gauge Invariance
We argue that an exact gauge invariance may disable some generic features of
the Standard Model which could otherwise manifest themselves at high energies.
One of them might be related to the spontaneous Lorentz invariance violation
(SLIV) which could provide an alternative dynamical approach to QED and
Yang-Mills theories with photon and non-Abelian gauge fields appearing as
massless Nambu-Goldstone bosons. To see some key features of the new physics
expected we propose partial rather than exact gauge invariance in an extended
SM framework. This principle applied, in some minimal form, to the weak
hypercharge gauge field B_{mu} and its interactions leads to SLIV with B field
components appearing as the massless Nambu-Goldstone modes, and provides a
number of distinctive Lorentz beaking effects. Being naturally suppressed at
low energies they may become detectable in high energy physics and
astrophysics. Some of the most interesting SLIV processes are considered in
significant detail.Comment: 32 pages, extended version, to appear in Eur.Phys.J.