3,484 research outputs found
Wedge Local Deformations of Charged Fields leading to Anyonic Commutation Relations
The method of deforming free fields by using multiplication operators on Fock
space, introduced by G. Lechner in [11], is generalized to a charged free field
on two- and three-dimensional Minkowski space. In this case the deformation
function can be chosen in such a way that the deformed fields satisfy
generalized commutation relations, i.e. they behave like Anyons instead of
Bosons. The fields are "polarization free" in the sense that they create only
one-particle states from the vacuum and they are localized in wedges (or "paths
of wedges"), which makes it possible to circumvent a No-Go theorem by J. Mund
[12], stating that there are no free Anyons localized in spacelike cones. The
two-particle scattering matrix, however, can be defined and is different from
unity
String-- and Brane--Localized Causal Fields in a Strongly Nonlocal Model
We study a weakly local, but nonlocal model in spacetime dimension
and prove that it is maximally nonlocal in a certain specific quantitative
sense. Nevertheless, depending on the number of dimensions , it has
string--localized or brane--localized operators which commute at spatial
distances. In two spacetime dimensions, the model even comprises a covariant
and local subnet of operators localized in bounded subsets of Minkowski space
which has a nontrivial scattering matrix. The model thus exemplifies the
algebraic construction of local observables from algebras associated with
nonlocal fields.Comment: paper re-written with a change of emphasis and new result
Tuning of structure inversion asymmetry by the -doping position in (001)-grown GaAs quantum wells
Structure and bulk inversion asymmetry in doped (001)-grown GaAs quantum
wells is investigated by applying the magnetic field induced photogalvanic
effect. We demonstrate that the structure inversion asymmetry (SIA) can be
tailored by variation of the delta-doping layer position. Symmetrically-doped
structures exhibit a substantial SIA due to impurity segregation during the
growth process. Tuning the SIA by the delta-doping position we grow samples
with almost equal degrees of structure and bulk inversion asymmetry.Comment: 4 pages 2 figure
Energy deposition studies for the High-Luminosity Large Hadron Collider inner triplet magnets
A detailed model of the High Luminosity LHC inner triplet region with new
large-aperture Nb3Sn magnets, field maps, corrector packages, and segmented
tungsten inner absorbers was built and implemented into the FLUKA and MARS15
codes. In the optimized configuration, the peak power density averaged over the
magnet inner cable width is safely below the quench limit. For the integrated
luminosity of 3000 fb-1, the peak dose in the innermost magnet insulator ranges
from 20 to 35 MGy. Dynamic heat loads to the triplet magnet cold mass are
calculated to evaluate the cryogenic capability. In general, FLUKA and MARS
results are in a very good agreement.Comment: 24 p
An operator expansion for integrable quantum field theories
A large class of quantum field theories on 1+1 dimensional Minkowski space,
namely, certain integrable models, has recently been constructed rigorously by
Lechner. However, the construction is very abstract and the concrete form of
local observables in these models remains largely unknown. Aiming for more
insight into their structure, we establish a series expansion for observables,
similar but not identical to the well-known form factor expansion. This
expansion will be the basis for a characterization and explicit construction of
local observables, to be discussed elsewhere. Here, we establish the expansion
independent of the localization aspect, and analyze its behavior under
space-time symmetries. We also clarify relations with deformation methods in
quantum field theory, specifically, with the warped convolution in the sense of
Buchholz and Summers.Comment: minor corrections and clarifications, as published in J. Phys A; 24
page
Revisiting the hierarchical structure of the 24 VIA character strengths: Three global dimensions may suffice to capture their essence
The Values in Action (VIA) framework maps 24 character strengths onto six more abstract virtues through a theoretical classification. However, compared to other individual difference constructs, there is little consensus about the factor-analytic structure of the VIA trait space. Applying Horn's parallel analysis, Goldberg’s Bass-ackwards approach, and cross-country congruency analysis, we scrutinize the factor-analytic solutions-hierarchy of the 24 VIA strengths with the aim to identify one or more useful global levels of abstraction (akin to the Big Five, HEXACO/Big Six, or personality metatraits). We assessed the 24 character strengths with the psychometrically refined IPIP-VIA-R inventory in two large and heterogeneous samples from Germany and the UK (total N ≈ 2,000). Results suggested that three global dimensions suffice to capture the essence of character strengths: Level III recovered more than 50% of the total variation of the 24 character strengths in well-interpretable, global/general, cross-culturally replicable dimensions. We provisionally labeled them positivity, dependability, and mastery. Their superordinate Level-II-dimensions were reminiscent of the "Big Two" personality metatraits Dynamism and Social Self-Regulation. Our results advance the understanding of the VIA character trait space and may serve as a basis for developing scales to assess these global dimensions
Energy Deposition Studies for the Hi-Lumi LHC Inner Triplet Magnets
A detailed model of the High Luminosity LHC inner triplet region with new
large-aperture Nb3Sn magnets, field maps, corrector packages, and segmented
tungsten inner absorbers was built and implemented into the FLUKA and MARS15
codes. In the optimized configuration, the peak power density averaged over the
magnet inner cable width is safely below the quench limit. For the integrated
luminosity of 3000 fb -1, the peak dose in the innermost magnet insulator
ranges from 20 to 35 MGy. Dynamic heat loads to the triplet magnet cold mass
are calculated to evaluate the cryogenic capability. In general, FLUKA and MARS
results are in a very good agreement.Comment: 4 pp. Presented paper at the 5th International Particle Accelerator
Conference, June 15 -20, 2014, Dresden, German
Spin polarized electric currents in semiconductor heterostructures induced by microwave radiation
We report on microwave (mw) radiation induced electric currents in
(Cd,Mn)Te/(Cd,Mg)Te and InAs/(In,Ga)As quantum wells subjected to an external
in-plane magnetic field. The current generation is attributed to the
spin-dependent energy relaxation of electrons heated by mw radiation. The
relaxation produces equal and oppositely directed electron flows in the spin-up
and spin-down subbands yielding a pure spin current. The Zeeman splitting of
the subbands in the magnetic field leads to the conversion of the spin flow
into a spin-polarized electric current.Comment: 3 pages, 4 figure
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