48,757 research outputs found
Longitudinal profiles of Extensive Air Showers with inclusion of charm and bottom particles
Charm and bottom particles are rare in Extensive Air Showers but the effect
of its presence can be radical in the development of the Extensive Air Showers
(EAS). If such particles arise with a large fraction of the primary energy,
they can reach large atmospheric depths, depositing its energy in deeper layers
of the atmosphere. As a consequence, the EAS observables (, and
) will be modified, as well as the shape of the longitudinal profile
of the energy deposited in the atmosphere. In this paper, we will modify the
CORSIKA Monte Carlo by the inclusion of charm and bottom production in the
first interaction of the primary cosmic ray. Results for different selections
of the typical values of the heavy particles and distinct production
models will be presented.Comment: Replacement of tex file by the correct versio
Discerning Elementary Particles
We extend the quantum-mechanical results of Muller & Saunders (2008)
establishing the weak discernibility of an arbitrary number of similar fermions
in finite-dimensional Hilbert-spaces in two ways: (a) from fermions to bosons
for all finite-dimensional Hilbert-spaces; and (b) from finite-dimensional to
infinite-dimensional Hilbert-spaces for all elementary particles. In both cases
this is performed using operators whose physical significance is beyond
doubt.This confutes the currently dominant view that (A) the quantum-mechanical
description of similar particles conflicts with Leibniz's Principle of the
Identity of Indiscernibles (PII); and that (B) the only way to save PII is by
adopting some pre-Kantian metaphysical notion such as Scotusian haecceittas or
Adamsian primitive thisness. We take sides with Muller & Saunders (2008)
against this currently dominant view, which has been expounded and defended by,
among others, Schr\"odinger, Margenau, Cortes, Dalla Chiara, Di Francia,
Redhead, French, Teller, Butterfield, Mittelstaedt, Giuntini, Castellani,
Krause and Huggett.Comment: Final Version. To appear in Philosophy of Science, July 200
SO(3) Yang-Mills theory on the lattice
We numerically investigate the phase structure of pure SO(3) LGT at zero and
non-zero temperature in the presence of a Z2 blind monopole chemical potential.
The physical meaning of the different phases, a possible symmetry breaking
mechanism as well as the existence of an order parameter for the finite
temperature phase transition are discussed.Comment: 3 pages, 2 figures LaTeX file. Uses espcrc2 style and amssymb
package. Talk given at Lattice2002(nonzerot), Boston. Corrected version with
one added referenc
SO(3) vs. SU(2) Yang-Mills theory on the lattice: an investigation at non-zero temperature
The adjoint SU(2) lattice gauge theory in 3+1 dimensions with the Wilson
plaquette action modified by a Z(2) monopole suppression term is reinvestigated
with special emphasis on the existence of a finite-temperature phase transition
decoupling from the well-known bulk transitions.Comment: 13 pages, 9 figures. Based on contributions to CONFINEMENT 2003 and
Lattice2003(topology). To be published in Proceedings of CONFINEMENT 2003,
Tokyo, Japa
Anomalous Transport Processes in Anisotropically Expanding Quark-Gluon Plasmas
We derive an expression for the anomalous viscosity in an anisotropically
expanding quark-gluon-plasma, which arises from interactions of thermal partons
with dynamically generated color fields. The anomalous viscosity dominates over
the collisional viscosity for large velocity gradients or weak coupling. This
effect may provide an explanation for the apparent ``nearly perfect'' liquidity
of the matter produced in nuclear collisions at RHIC without the assumption
that it is a strongly coupled state.Comment: 31 pages, 1 figure, some typos in published version are correcte
Global Facilitation of Attended Features Is Obligatory and Restricts Divided Attention
Peer reviewedPublisher PD
``Plug and play'' systems for quantum cryptography
We present a time-multiplexed interferometer based on Faraday mirrors, and
apply it to quantum key distribution. The interfering pulses follow exactly the
same spatial path, ensuring very high stability and self balancing. Use of
Faraday mirrors compensates automatically any birefringence effects and
polarization dependent losses in the transmitting fiber. First experimental
results show a fringe visibility of 0.9984 for a 23km-long interferometer,
based on installed telecom fibers.Comment: LaTex, 6 pages, with 2 Postscript figures, Submitted to Applied
Physics Letter
Tensor product representations of the quantum double of a compact group
We consider the quantum double D(G) of a compact group G, following an
earlier paper. We use the explicit comultiplication on D(G) in order to build
tensor products of irreducible *-representations. Then we study their behaviour
under the action of the R-matrix, and their decomposition into irreducible
*-representations. The example of D(SU(2)) is treated in detail, with explicit
formulas for direct integral decomposition (`Clebsch-Gordan series') and
Clebsch-Gordan coefficients. We point out possible physical applications.Comment: LaTeX2e, 27 pages, corrected references, accepted by Comm.Math.Phy
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