1,756 research outputs found
The Contentious Politics of Hospitality: Intra-EU Mobility and Social Rights
Intra-Eu mobility has become increasingly contested. Despite empirical evidence showing that migrants are not a burden for the receiving countries, a growing number of voters think that nationals should have priority in terms of jobs and welfare. In a realist perspective, this \ue2\u80\u9cnativist\ue2\u80\u9d turn cannot be ignored, as it might undermine the very idea of EU citizenship. While nondiscrimination, as enshrined in the Treaties, should certainly remain the first order principle to defend free movement from a legal and normative point of view, in the present predicament it might be reasonable to complement it with the less demanding principle of \ue2\u80\u9chospitality\ue2\u80\u9d. Practically, this would mean to give back to Member States a modicum of autonomy in filtering the access to social benefits for inactive or non-resident persons
Epsilon-Near-Zero Al-Doped ZnO for Ultrafast Switching at Telecom Wavelengths: Outpacing the Traditional Amplitude-Bandwidth Trade-Off
Transparent conducting oxides have recently gained great attention as
CMOS-compatible materials for applications in nanophotonics due to their low
optical loss, metal-like behavior, versatile/tailorable optical properties, and
established fabrication procedures. In particular, aluminum doped zinc oxide
(AZO) is very attractive because its dielectric permittivity can be engineered
over a broad range in the near infrared and infrared. However, despite all
these beneficial features, the slow (> 100 ps) electron-hole recombination time
typical of these compounds still represents a fundamental limitation impeding
ultrafast optical modulation. Here we report the first epsilon-near-zero AZO
thin films which simultaneously exhibit ultra-fast carrier dynamics (excitation
and recombination time below 1 ps) and an outstanding reflectance modulation up
to 40% for very low pump fluence levels (< 4 mJ/cm2) at the telecom wavelength
of 1.3 {\mu}m. The unique properties of the demonstrated AZO thin films are the
result of a low temperature fabrication procedure promoting oxygen vacancies
and an ultra-high carrier concentration. As a proof-of-concept, an all-optical
AZO-based plasmonic modulator achieving 3 dB modulation in 7.5 {\mu}m and
operating at THz frequencies is numerically demonstrated. Our results overcome
the traditional "modulation depth vs. speed" trade-off by at least an order of
magnitude, placing AZO among the most promising compounds for
tunable/switchable nanophotonics.Comment: 14 pages, 9 figures, 1 tabl
Vector boson production at hadron colliders: a fully exclusive QCD calculation at NNLO
We consider QCD radiative corrections to the production of W and Z bosons in
hadron collisions. We present a fully exclusive calculation up to
next-to-next-to-leading order (NNLO) in QCD perturbation theory. To perform
this NNLO computation, we use a recently proposed version of the subtraction
formalism. The calculation includes the gamma-Z interference, finite-width
effects, the leptonic decay of the vector bosons and the corresponding spin
correlations. Our calculation is implemented in a parton level Monte Carlo
program. The program allows the user to apply arbitrary kinematical cuts on the
final-state leptons and the associated jet activity, and to compute the
corresponding distributions in the form of bin histograms. We show selected
numerical results at the Tevatron and the LHC.Comment: 7 pages, 3 ps figure
Universality of transverse-momentum resummation and hard factors at the NNLO
We consider QCD radiative corrections to the production of colourless
high-mass systems in hadron collisions. The logarithmically-enhanced
contributions at small transverse momentum are treated to all perturbative
orders by a universal resummation formula that depends on a single
process-dependent hard factor. We show that the hard factor is directly related
to the all-order virtual amplitude of the corresponding partonic process. The
direct relation is universal (process independent), and it is expressed by an
all-order factorization formula that we explicitly evaluate up to the
next-to-next-to-leading order (NNLO) in QCD perturbation theory. Once the NNLO
scattering amplitude is available, the corresponding hard factor is directly
determined: it controls NNLO contributions in resummed calculations at full
next-to-next-to-leading logarithmic accuracy, and it can be used in
applications of the q_T subtraction formalism to perform fully-exclusive
perturbative calculations up to NNLO. The universality structure of the hard
factor and its explicit NNLO form are also extended to the related formalism of
threshold resummation.Comment: References added. Version accepted for publication on NP
Threshold resummation at NLL accuracy and soft-virtual cross sections at NLO
We consider QCD radiative corrections to the production of colourless
high-mass systems in hadron collisions. We show that the recent computation of
the soft-virtual corrections to Higgs boson production at NLO [1] together
with the universality structure of soft-gluon emission can be exploited to
extract the general expression of the hard-virtual coefficient that contributes
to threshold resummation at NLL accuracy. The hard-virtual coefficient is
directly related to the process-dependent virtual amplitude through a universal
(process-independent) factorization formula that we explicitly evaluate up to
three-loop order. As an application, we present the explicit expression of the
soft-virtual NLO corrections for the production of an arbitrary colourless
system. In the case of the Drell-Yan process, we confirm the recent result of
Ref.[2].Comment: Slightly expanded text, one reference added, version published on NP
Worker mobility under attack? Explaining labour market chauvinism in the EU
The aim of this paper is to investigate citizen views on the free movement of workers within the European Union (EU). We are interested in how situational and relational factors affect labour market chauvinist attitudes. Drawing on the threat theory, we advance new hypotheses on the role of intertemporal relative deprivation in amplifying chauvinist inclinations. From the intergroup contact theory and transnational approaches, we borrow insights on the role played by cross-border experiences and inclusion in discursive and associational networks in containing chauvinism. The analysis uses the original \u2018Reconciling Economic and Social Europe\u2019 (REScEU) survey conducted in six EU countries (i.e., France, Germany, Italy, Poland, Spain and Sweden) in the fall of 2016. The article shows that \u2013 though rooted in class and status positions \u2013 chauvinist attitudes are clearly sensitive to contingent situations and lifeworld experiences
Associated WH production at hadron colliders: a fully exclusive QCD calculation at NNLO
We consider QCD radiative corrections to Standard Model Higgs boson
production in association with a W boson in hadron collisions. We present a
fully exclusive calculation up to next-to-next-to-leading order (NNLO) in QCD
perturbation theory. To perform this NNLO computation, we use a recently
proposed version of the subtraction formalism. Our calculation includes
finite-width effects, the leptonic decay of the W boson with its spin
correlations, and the decay of the Higgs boson into a bbbar pair. We present
selected numerical results at the Tevatron and the LHC.Comment: 7 pages, 2 figure
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