609 research outputs found
Dephasing in coherently-split quasicondensates
We numerically model the evolution of a pair of coherently split
quasicondensates. A truly one-dimensional case is assumed, so that the loss of
the (initially high) coherence between the two quasicondensates is due to
dephasing only, but not due to the violation of integrability and subsequent
thermalization (which are excluded from the present model). We confirm the
subexponential time evolution of the coherence between two quasicondensates
, experimentally observed by S. Hofferberth {\em
et. al.}, Nature {\bf 449}, 324 (2007). The characteristic time is found
to scale as the square of the ratio of the linear density of a quasicondensate
to its temperature, and we analyze the full distribution function of the
interference contrast and the decay of the phase correlation.Comment: revtex4, 9 pages, 8 figure
Fluctuations and stochastic processes in one-dimensional many-body quantum systems
We study the fluctuation properties of a one-dimensional many-body quantum
system composed of interacting bosons, and investigate the regimes where
quantum noise or, respectively, thermal excitations are dominant. For the
latter we develop a semiclassical description of the fluctuation properties
based on the Ornstein-Uhlenbeck stochastic process. As an illustration, we
analyze the phase correlation functions and the full statistical distributions
of the interference between two one-dimensional systems, either independent or
tunnel-coupled and compare with the Luttinger-liquid theory.Comment: 4 pages (revtex4), 4 color figures. Text substantially rewritten, two
figures adde
Origin Of The Far Off-Axis GRB171205A
We show that observed properties of the low luminosity GRB171205A and its
afterglow, like those of most other low-luminosity (LL) gamma ray bursts (GRBs)
associate with a supernova (SN), indicate that it is an ordinary SN-GRB, which
was produced by inverse Compton scattering of glory light by a highly
relativistic narrowly collimated jet ejected in a supernova explosion and
viewed from a far off-axis angle. As such, VLA/VLBI follow-up radio
observations of a superluminal displacement of its bright radio afterglow from
its parent supernova, will be able to test clearly whether it is an ordinary
SN-GRB viewed from far off-axis or it belongs to a distinct class of GRBs,
which are different from ordinary GRBs, and cannot be explained by standard
fireball models of GRBs as ordinary GRBsComment: 5 pages, 6 figures, updated data in Fig. 3, Corrected GRB angular
distance used in Fig.
corrections to polarized top decay into a charged Higgs
We calculate the radiative corrections to polarized top quark
decay into a charged Higgs boson and a massive bottom quark in two variants of
the two-Higgs-doublet model. The radiative corrections to the polarization
asymmetry of the decay may become as large as . We provide analytical
formulae for the unpolarized and polarized rates for and for . For our closed-form expressions for the unpolarized and
polarized rates become rather compact.Comment: 24 pages, 5 figures in the text, content modified, comments added,
appendices added, references updated, replaced with published versio
Prenatal diagnosis for haemophilia: A nationwide survey among female carriers in the Netherlands
Carriers of haemophilia face difficult choices regarding prenatal diagnosis, but little is known about the determinants that influence their decisions. The aim of this study was to assess the incidence of prenatal diagnosis and potential determinants affecting the choice for prenatal diagnosis. A nationwide survey was performed among all women who underwent carriership testing for haemophilia in the Netherlands between 1992 and 2004. Prenatal diagnosis was assessed i
Leptonic - and -decays: mass effects, polarization effects and radiative corrections
We calculate the radiative corrections to the unpolarized and the four
polarized spectrum and rate functions in the leptonic decay of a polarized into a polarized electron. The new feature of our calculation is that we
keep the mass of the final state electron finite which is mandatory if one
wants to investigate the threshold region of the decay. Analytical results are
given for the energy spectrum and the polar angle distribution of the final
state electron whose longitudinal and transverse polarization is calculated. We
also provide analytical results on the integrated spectrum functions. We
analyze the limit of our general results and investigate the
quality of the approximation. In the case we
discuss in some detail the role of the anomalous helicity flip
contribution of the final electron which survives the limit. The
results presented in this 0203048 also apply to the leptonic decays of
polarized -leptons for which we provide numerical results.Comment: 39 pages, 11 postscript figures added. Updated version. Four
references added. A few text improvements. Final version to appear in
Phys.Rev.
Political branding: sense of identity or identity crisis? An investigation of the transfer potential of the brand identity prism to the UK Conservative Party
Brands are strategic assets and key to achieving a competitive advantage. Brands can be seen as a heuristic device, encapsulating a series of values that enable the consumer to make quick and efficient choices. More recently, the notion of a political brand and the rhetoric of branding have been widely adopted by many political parties as they seek to differentiate themselves, and this has led to an emerging interest in the idea of the political brand. Therefore, this paper examines the UK Conservative Party brand under David Cameron’s leadership and examines the applicability of Kapferer’s brand identity prism to political branding. This paper extends and operationalises the brand identity prism into a ‘political brand identity network’ which identifies the inter-relatedness of the components of the corporate political brand and the candidate political brand. Crucial for practitioners, this model can demonstrate how the brand is presented and communicated to the electorate and serves as a useful mechanism to identify consistency within the corporate and candidate political brands
Resonant Thermoelectric Nanophotonics
Photodetectors are typically based either on photocurrent generation from electron–hole pairs in semiconductor structures or on bolometry for wavelengths that are below bandgap absorption. In both cases, resonant plasmonic and nanophotonic structures have been successfully used to enhance performance. Here, we show subwavelength thermoelectric nanostructures designed for resonant spectrally selective absorption, which creates large localized temperature gradients even with unfocused, spatially uniform illumination to generate a thermoelectric voltage. We show that such structures are tunable and are capable of wavelength-specific detection, with an input power responsivity of up to 38 V W^(–1), referenced to incident illumination, and bandwidth of nearly 3 kHz. This is obtained by combining resonant absorption and thermoelectric junctions within a single suspended membrane nanostructure, yielding a bandgap-independent photodetection mechanism. We report results for both bismuth telluride/antimony telluride and chromel/alumel structures as examples of a potentially broader class of resonant nanophotonic thermoelectric materials for optoelectronic applications such as non-bandgap-limited hyperspectral and broadband photodetectors
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