2,655 research outputs found
Understanding flavor mixing in Quantum Field Theory
We report on recent results showing that a rich non-perturbative vacuum
structure is associated with flavor mixing in Quantum Field Theory.
We treat explicitly the case of mixing among three generations of Dirac
fermions.
Exact oscillation formulas are presented exhibiting new features with respect
to the usual ones. CP and T violation are also discussed.Comment: 9 pages. Presented at the "International Conference on Flavor
Physics", Zhang-Jia-Jie, China, May 31 - June 6 200
Group theoretical aspects of neutrino mixing in Quantum Field Theory
By resorting to recent results on the Quantum Field Theory of mixed
particles, we discuss some aspects of three flavor neutrino mixing. Particular
emphasis is given to the related algebraic structures and their deformation in
the presence of CP violation. A novel geometric phase related to CP violation
is introduced.Comment: 10 pages, 2 figures. Presented at the XII International Baksan School
"Particles and Cosmology", Baksan Valley, Kabardino-Balkaria, Russian
Federation - April 21 - 26, 200
A new perspective in the dark energy puzzle from particle mixing phenomenon
We report on recent results on particle mixing and oscillations in quantum
field theory. We discuss the role played in cosmology by the vacuum condensate
induced by the neutrino mixing phenomenon. We show that it can contribute to
the dark energy of the universe.Comment: 11 pages, to be published on the review book "Dark Energy-Current
Advances and Ideas
Dissipation and quantization for composite systems
In the framework of 't Hooft's quantization proposal, we show how to obtain
from the composite system of two classical Bateman's oscillators a quantum
isotonic oscillator. In a specific range of parameters, such a system can be
interpreted as a particle in an effective magnetic field, interacting through a
spin-orbit interaction term. In the limit of a large separation from the
interaction region one can describe the system in terms of two irreducible
elementary subsystems which correspond to two independent quantum harmonic
oscillators.Comment: 9 page
Dissipation and Topologically Massive Gauge Theories in Pseudoeuclidean Plane
In the pseudo-euclidean metrics Chern-Simons gauge theory in the infrared
region is found to be associated with dissipative dynamics. In the infrared
limit the Lagrangian of 2+1 dimensional pseudo-euclidean topologically massive
electrodynamics has indeed the same form of the Lagrangian of the damped
harmonic oscillator. On the hyperbolic plane a set of two damped harmonic
oscillators, each other time-reversed, is shown to be equivalent to a single
undamped harmonic oscillator. The equations for the damped oscillators are
proven to be the same as the ones for the Lorentz force acting on two particles
carrying opposite charge in a constant magnetic field and in the electric
harmonic potential. This provides an immediate link with Chern-Simons-like
dynamics of Bloch electrons in solids propagating along the lattice plane with
hyperbolic energy surface. The symplectic structure of the reduced theory is
finally discussed in the Dirac constrained canonical formalism.Comment: 22 pages, LaTe
On Normal ordering and Canonical transformations in Thermal Field Theory
We look at a real scalar field in thermal equilibrium in the context of the
new normal ordering and field split defined by Evans and Steer. We show that
the field split defines a natural canonical transformation, but that this
transformation differs from others known in thermal field theory.Comment: 13 pages, LaTeX. (Revisions made to discussion and various small
errors in equations corrected
Quantum Groups, Coherent States, Squeezing and Lattice Quantum Mechanics
By resorting to the Fock--Bargmann representation, we incorporate the quantum
Weyl--Heisenberg (-WH) algebra into the theory of entire analytic functions.
The main tool is the realization of the --WH algebra in terms of finite
difference operators. The physical relevance of our study relies on the fact
that coherent states (CS) are indeed formulated in the space of entire analytic
functions where they can be rigorously expressed in terms of theta functions on
the von Neumann lattice. The r\^ole played by the finite difference operators
and the relevance of the lattice structure in the completeness of the CS system
suggest that the --deformation of the WH algebra is an essential tool in the
physics of discretized (periodic) systems. In this latter context we define a
quantum mechanics formalism for lattice systems.Comment: 22 pages, TEX file, DFF188/9/93 Firenz
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