4,576 research outputs found
Absence of Embedded Mass Shells: Cerenkov Radiation and Quantum Friction
We show that, in a model where a non-relativistic particle is coupled to a
quantized relativistic scalar Bose field, the embedded mass shell of the
particle dissolves in the continuum when the interaction is turned on, provided
the coupling constant is sufficiently small. More precisely, under the
assumption that the fiber eigenvectors corresponding to the putative mass shell
are differentiable as functions of the total momentum of the system, we show
that a mass shell could exist only at a strictly positive distance from the
unperturbed embedded mass shell near the boundary of the energy-momentum
spectrum.Comment: Revised version: a remark added at the end of Section
Gauge-invariant charged, monopole and dyon fields in gauge theories
We propose explicit recipes to construct the euclidean Green functions of
gauge-invariant charged, monopole and dyon fields in four-dimensional gauge
theories whose phase diagram contains phases with deconfined electric and/or
magnetic charges. In theories with only either abelian electric or magnetic
charges, our construction is an euclidean version of Dirac's original proposal,
the magnetic dual of his proposal, respectively. Rigorous mathematical control
is achieved for a class of abelian lattice theories. In theories where electric
and magnetic charges coexist, our construction of Green functions of
electrically or magnetically charged fields involves taking an average over
Mandelstam strings or the dual magnetic flux tubes, in accordance with Dirac's
flux quantization condition. We apply our construction to 't Hooft-Polyakov
monopoles and Julia-Zee dyons. Connections between our construction and the
semiclassical approach are discussed
Infraparticle Scattering States in Non-Relativistic QED: II. Mass Shell Properties
We study the infrared problem in the usual model of QED with non-relativistic
matter. We prove spectral and regularity properties characterizing the mass
shell of an electron and one-electron infraparticle states of this model. Our
results are crucial for the construction of infraparticle scattering states,
which are treated in a separate paper.Comment: AMS Latex, 45 pages, 2 figure
Probing Non-Abelian Statistics in nu=12/5 Quantum Hall State
The tunneling current and shot noise of the current between two Fractional
Quantum Hall (FQH) edges in the FQH state in electronic
Mach-Zehnder interferometer are studied. It is shown that the tunneling current
and shot noise can be used to probe the existence of parafermion
statistics in the FQH state. More specifically, the dependence of
the current on the Aharonov-Bohm flux in the Read-Rezayi state is asymmetric
under the change of the sign of the applied voltage. This property is absent in
the Abelian Laughlin states. Moreover the Fano factor can exceed 12.7 electron
charges in the FQH state . This number well exceeds the maximum
possible Fano factor in all Laughlin states and the Moore-Read
state which was shown previously to be and respectively.Comment: 10 pages, 6 figure
Monopole creation operators as confinement--deconfinement order parameters
We study numerically two versions of the monopole creation operators proposed
by Frohlich and Marchetti. The disadvantage of the old version of the monopole
creation operator is due to visibility of the Dirac string entering the
definition of the creation operator in the theories with coexisting electric
and magnetic charges. This problem does not exist for the new creation operator
which is rather complicated. Using the Abelian Higgs model with a compact gauge
field we show that both definitions of the monopole creation operator can serve
as order parameters for the confinement--deconfinement phase transition. The
value of the monopole condensate for the old version depends on the length of
Dirac string. However, as soon as the length is fixed the old operator
certainly discriminates between the phases with condensed and non--condensed
monopoles.Comment: 12 pages, 7 figures, LaTeX2
On the Atomic Photoeffect in Non-relativistic QED
In this paper we present a mathematical analysis of the photoelectric effect
for one-electron atoms in the framework of non-relativistic QED. We treat
photo-ionization as a scattering process where in the remote past an atom in
its ground state is targeted by one or several photons, while in the distant
future the atom is ionized and the electron escapes to spacial infinity. Our
main result shows that the ionization probability, to leading order in the
fine-structure constant, , is correctly given by formal time-dependent
perturbation theory, and, moreover, that the dipole approximation produces an
error of only sub-leading order in . In this sense, the dipole
approximation is rigorously justified.Comment: 25 page
Design of the Pluto Event Generator
We present the design of the simulation package Pluto, aimed at the study of
hadronic interactions at SIS and FAIR energies. Its main mission is to offer a
modular framework with an object-oriented structure, thereby making additions
such as new particles, decays of resonances, new models up to modules for
entire changes easily applicable. Overall consistency is ensured by a plugin-
and distribution manager. Particular features are the support of a modular
structure for physics process descriptions, and the possibility to access the
particle stream for on-line modifications. Additional configuration and
self-made classes can be attached by the user without re-compiling the package,
which makes Pluto extremely configurable.Comment: Presented at the 17th International Conference on Computing in High
Energy and Nuclear Physic
Design of the Pluto Event Generator
We present the design of the simulation package Pluto, aimed at the study of
hadronic interactions at SIS and FAIR energies. Its main mission is to offer a
modular framework with an object-oriented structure, thereby making additions
such as new particles, decays of resonances, new models up to modules for
entire changes easily applicable. Overall consistency is ensured by a plugin-
and distribution manager. Particular features are the support of a modular
structure for physics process descriptions, and the possibility to access the
particle stream for on-line modifications. Additional configuration and
self-made classes can be attached by the user without re-compiling the package,
which makes Pluto extremely configurable.Comment: Presented at the 17th International Conference on Computing in High
Energy and Nuclear Physic
Design of the Pluto Event Generator
We present the design of the simulation package Pluto, aimed at the study of
hadronic interactions at SIS and FAIR energies. Its main mission is to offer a
modular framework with an object-oriented structure, thereby making additions
such as new particles, decays of resonances, new models up to modules for
entire changes easily applicable. Overall consistency is ensured by a plugin-
and distribution manager. Particular features are the support of a modular
structure for physics process descriptions, and the possibility to access the
particle stream for on-line modifications. Additional configuration and
self-made classes can be attached by the user without re-compiling the package,
which makes Pluto extremely configurable.Comment: Presented at the 17th International Conference on Computing in High
Energy and Nuclear Physic
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