107 research outputs found
Citizenship:Contrasting Dynamics at the Interface of Integration and Constitutionalism
EUDO Citizenship ObservatoryThis paper explores the different ways in which citizenship has played a role in polity formation in the
context of the European Union. It focuses on both the ‘integration’ and the ‘constitution’ dimensions.
The paper thus has two substantive sections. The first addresses the role of citizenship of the Union,
examining the dynamic relationship between this concept, the role of the Court of Justice, and the free
movement dynamic of EU law. The second turns to citizenship in the Union, looking at some recent
political developments under which concepts of citizenship, and democratic membership as a key
dimension of citizenship, have been given greater prominence. One key finding of the paper is that
there is a tension between citizenship of the Union, as part of the EU's ‘old’ incremental
constitutionalism based on the constitutionalisation of the existing Treaties, and citizenship in the
Union, where the possibilities of a ‘new’ constitutionalism based on renewed constitutional documents
have yet to be fully realise
Simulating Quantum Dynamics with Entanglement Mean Field Theory
Exactly solvable many-body systems are few and far between, and the utility
of approximate methods cannot be overestimated. Entanglement mean field theory
is an approximate method to handle such systems. While mean field theories
reduce the many-body system to an effective single-body one, entanglement mean
field theory reduces it to a two-body system. And in contrast to mean field
theories where the self-consistency equations are in terms of single-site
physical parameters, those in entanglement mean field theory are in terms of
both single- and two-site parameters. Hitherto, the theory has been applied to
predict properties of the static states, like ground and thermal states, of
many-body systems. Here we give a method to employ it to predict properties of
time-evolved states. The predictions are then compared with known results of
paradigmatic spin Hamiltonians.Comment: 8 pages, 3 figure
A fundamental test of the Higgs Yukawa coupling at RHIC in A+A collisions
Searches for the intermediate boson, , the heavy quantum of the Weak
Interaction, via its semi-leptonic decay, , in the 1970's instead
discovered unexpectedly large hadron production at high , notably ,
which provided a huge background of from internal and external
conversions. Methods developed at the CERN ISR which led to the discovery of
direct-single- in 1974, later determined to be from the semi-leptonic
decay of charm which had not yet been discovered, were used by PHENIX at RHIC
to make precision measurements of heavy quark production in p-p and Au+Au
collisions, leading to the puzzle of apparent equal suppression of light and
heavy quarks in the QGP. If the Higgs mechanism gives mass to gauge bosons but
not to fermions, then a proposal that all 6 quarks are nearly massless in a
QGP, which would resolve the puzzle, can not be excluded. This proposal can be
tested with future measurements of heavy quark correlations in A+A collisionsComment: 12 pages, 16 figures, 26th Winter Workshop on Nuclear Dynamics, Ocho
Rios, Jamaica WI, January 2-9, 2010. Corrected citation of 1974 direct single
lepton discover
Gauge thresholds in the presence of oblique magnetic fluxes
We compute the one-loop partition function and analyze the conditions for
tadpole cancellation in type I theories compactified on tori in the presence of
internal oblique magnetic fields. We check open - closed string channel duality
and discuss the effect of T-duality. We address the issue of the quantum
consistency of the toroidal model with stabilized moduli recently proposed by
Antoniadis and Maillard (AM). We then pass to describe the computation of
one-loop threshold corrections to the gauge couplings in models of this kind.
Finally we briefly comment on coupling unification and dilaton stabilization in
phenomenologically more viable modelsComment: 34 pages, 2 figures; references added, major changes to the
discussion of the model proposed by Antoniadis and Maillar
Physics at the LHC: a short overview
The CERN Large Hadron Collider (LHC) started operation a few months ago. The
machine will deliver proton-proton and nucleus-nucleus collisions at energies
as high as sqrt(s)=14 TeV and luminosities up to L~10^{34} cm^{-2}s^{-1}, never
reached before. The main open scientific questions that the seven LHC
experiments -- ATLAS, CMS, ALICE, LHCb, TOTEM, LHCf and MOEDAL -- aim to solve
in the coming years are succinctly reviewed.Comment: 9 pages, 16 plots. Invited review talk Hot-Quarks 2010, La
Londe-Les-Maures, July 2010. J. Phys. Conf. Ser. 270, 012001 (2011). Minor
typos correcte
Black holes with hair
I review some recent results on black holes with hair. I focus on the magnetically charged black holes in spontaneously broken Yang-Mills-Higgs theories and on the related self-gravitating magnetic monopoles. Some implications for black hole thermodynamics are discussed
- …