945 research outputs found
Patterns in the Fermion Mixing Matrix, a bottom-up approach
We first obtain the most general and compact parametrization of the unitary
transformation diagonalizing any 3 by 3 hermitian matrix H, as a function of
its elements and eigenvalues. We then study a special class of fermion mass
matrices, defined by the requirement that all of the diagonalizing unitary
matrices (in the up, down, charged lepton and neutrino sectors) contain at
least one mixing angle much smaller than the other two. Our new parametrization
allows us to quickly extract information on the patterns and predictions
emerging from this scheme. In particular we find that the phase difference
between two elements of the two mass matrices (of the sector in question)
controls the generic size of one of the observable fermion mixing angles: i.e.
just fixing that particular phase difference will "predict" the generic value
of one of the mixing angles, irrespective of the value of anything else.Comment: 29 pages, 3 figures, references added, to appear in PR
Isomorphisms between Quantum Group Covariant q-Oscillator Systems Defined for q and 1/q
It is shown that there exists an isomorphism between q-oscillator systems
covariant under and . By the isomorphism, the
defining relations of covariant q-oscillator system are
transmuted into those of . It is also shown that the similar
isomorphism exists for the system of q-oscillators covariant under the quantum
supergroup . Furthermore the cases of q-deformed Lie
(super)algebras constructed from covariant q-oscillator systems are considered.
The isomorphisms between q-deformed Lie (super)algebras can not obtained by the
direct generalization of the one for covariant q-oscillator systems.Comment: LaTeX 13pages, RCNP-07
Immigration Federalism: A Reappraisal
This Article identifies how the current spate of state and local regulation is changing the way elected officials, scholars, courts, and the public think about the constitutional dimensions of immigration law and governmental responsibility for immigration enforcement. Reinvigorating the theoretical possibilities left open by the Supreme Court in its 1875 Chy Lung v. Freeman decision, state and local offi- cials characterize their laws as unavoidable responses to the policy problems they face when they are squeezed between the challenges of unauthorized migration and the federal government’s failure to fix a broken system. In the October 2012 term, in Arizona v. United States, the Court addressed, but did not settle, the difficult empirical, theoretical, and constitutional questions necessitated by these enactments and their attendant justifications. Our empirical investigation, however, discovered that most state and local immigration laws are not organic policy responses to pressing demographic challenges. Instead, such laws are the product of a more nuanced and politicized process in which demographic concerns are neither neces- sary nor sufficient factors and in which federal inactivity and subfederal activity are related phenomena, fomented by the same actors. This Article focuses on the con- stitutional and theoretical implications of these processes: It presents an evidence- based theory of state and local policy proliferation; it cautions legal scholars to rethink functionalist accounts for the rise of such laws; and it advises courts to reassess their use of traditional federalism frameworks to evaluate these sub federal enactments
SU(3) Mixing for Excited Mesons
The SU(3)-flavor symmetry breaking and the quark-antiquark annihilation
mechanism are taken into account for describing the singlet-octet mixing for
several nonets assigned by Particle Data Group(PDG). This task is approached
with the mass matrix formalism
Generalized boson algebra and its entangled bipartite coherent states
Starting with a given generalized boson algebra U_(h(1)) known as the
bosonized version of the quantum super-Hopf U_q[osp(1/2)] algebra, we employ
the Hopf duality arguments to provide the dually conjugate function algebra
Fun_(H(1)). Both the Hopf algebras being finitely generated, we produce a
closed form expression of the universal T matrix that caps the duality and
generalizes the familiar exponential map relating a Lie algebra with its
corresponding group. Subsequently, using an inverse Mellin transform approach,
the coherent states of single-node systems subject to the U_(h(1)) symmetry
are found to be complete with a positive-definite integration measure.
Nonclassical coalgebraic structure of the U_(h(1)) algebra is found to
generate naturally entangled coherent states in bipartite composite systems.Comment: 15pages, no figur
Mechanism for the Singlet to Triplet Superconductivity Crossover in Quasi-One-Dimensional Organic Conductors
Superconductivity of quasi-one-dimensional organic conductors with a
quarter-filled band is investigated using the two-loop renormalization group
approach to the extended Hubbard model for which both the single electron
hopping t_{\perp} and the repulsive interaction V_{\perp} perpendicular to the
chains are included. For a four-patches Fermi surface with deviations to
perfect nesting, we calculate the response functions for the dominant
fluctuations and possible superconducting states. By increasing V_{\perp}, it
is shown that a d-wave (singlet) to f-wave (triplet) superconducting state
crossover occurs, and is followed by a vanishing spin gap. Furthermore, we
study the influence of a magnetic field through the Zeeman coupling, from which
a triplet superconducting state is found to emerge.Comment: 11 pages, 15 figures, published versio
Spin-triplet superconductivity in repulsive Hubbard models with disconnected Fermi surfaces: a case study on triangular and honeycomb lattices
We propose that spin-fluctuation-mediated spin-triplet superconductivity may
be realized in repulsive Hubbard models with disconnected Fermi surfaces. The
idea is confirmed for Hubbard models on triangular (dilute band filling) and
honeycomb (near half-filling) lattices using fluctuation exchange
approximation, where triplet pairing order parameter with f-wave symmetry is
obtained. Possible relevance to real superconductors is suggested.Comment: 5 pages, 6 figures, RevTeX, uses epsf.sty and multicol.st
Chaos in Static Axisymmetric Spacetimes I : Vacuum Case
We study the motion of test particle in static axisymmetric vacuum spacetimes
and discuss two criteria for strong chaos to occur: (1) a local instability
measured by the Weyl curvature, and (2) a tangle of a homoclinic orbit, which
is closely related to an unstable periodic orbit in general relativity. We
analyze several static axisymmetric spacetimes and find that the first
criterion is a sufficient condition for chaos, at least qualitatively. Although
some test particles which do not satisfy the first criterion show chaotic
behavior in some spacetimes, these can be accounted for the second criterion.Comment: More comments for the quantitative estimation of chaos are added, and
some inappropriate terms are changed. This will appear on Class. Quant. Gra
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