1,070 research outputs found
Resonance-assisted tunneling in deformed optical microdisks with a mixed phase space
The lifetimes of optical modes in whispering-gallery cavities depend crucially on the underlying classical ray dynamics, and they may be spoiled by the presence of classical nonlinear resonances due to resonance-assisted tunneling. Here we present an intuitive semiclassical picture that allows for an accurate prediction of decay rates of optical modes in systems with a mixed phase space. We also extend the perturbative description from near-integrable systems to systems with a mixed phase space, and we find equally good agreement. Both approaches are based on the approximation of the actual ray dynamics by an integrable Hamiltonian, which enables us to perform a semiclassical quantization of the system and to introduce a ray-based description of the decay of optical modes. The coupling between them is determined either perturbatively or semiclassically in terms of complex paths
The breaking of the flavour permutational symmetry: Mass textures and the CKM matrix
Different ansaetze for the breaking of the flavour permutational symmetry
according to S(3)L X S(3)R in S(2)L X S(2) give different Hermitian mass
matrices of the same modified Fritzsch type, which differ in the symmetry
breaking pattern. In this work we obtain a clear and precise indication on the
preferred symmetry breaking scheme from a fit of the predicted theoretical Vckm
to the experimentally determined absolute values of the elements of the CKM
matrix. The preferred scheme leads to simple mass textures and allows us to
compute the CKM mixing matrix, the Jarlskog invariant J, and the three inner
angles of the unitarity triangle in terms of four quark mass ratios and only
one free parameter: the CP violating phase Phi. Excellent agreement with the
experimentally determined absolute values of the entries in the CKM matrix is
obtained for Phi = 90 deg. The corresponding computed values of the Jarlskog
invariant and the inner angles are J = 3.00 X 10^-5, alpha= 84 deg, beta= 24
deg and gamma =72 deg in very good agreement with current data on CP violation
in the neutral kaon-antikaon system and oscillations in the B-Bbar system.Comment: 21 pages, 1 fig. Content enlarged, references added and typos
corrected. To be published in Phys Rev
A Search for the Fourth SM Family Fermions and E_6 Quarks at Colliders
The potential of colliders to investigate the fourth SM
family fermions predicted by flavour democracy has been analyzed. It is shown
that muon colliders are advantageous for both pair production of fourth family
fermions and resonance production of fourth family quarkonia. Also isosinglet
quarks production at colliders has been investigated.Comment: 9 pages, 5 table
Implications of the KamLAND Measurement on the Lepton Flavor Mixing Matrix and the Neutrino Mass Matrix
We explore some important implications of the KamLAND measurment on the
lepton flavor mixing matrix and the neutrino mass matrix . The
model-independent constraints on nine matrix elements of are obtained to a
reasonable degree of accuracy. We find that nine two-zero textures of are
compatible with current experimental data, but two of them are only marginally
allowed. Instructive predictions are given for the absolute neutrino masses,
Majorana phases of CP violation, effective masses of the tritium beta decay and
neutrinoless double beta decay.Comment: RevTex 15 pages (4 PS figures included
Glueball enhancement by color de-confinement
High energy heavy ion collisions lead to the formation of a strong coupling
de-confined phase in which the lightest glueballs are numerous and stable. We
analyze how their properties manifest themselves in experimental spectra and
show that they provide a good signature for color de-confinement.Comment: 9 pages, 4 figure
The scalar glueball spectrum
We discuss scenarios for scalar glueballs using arguments based on sum rules,
spectral decomposition, the approximation, the scales of the
strong interaction and the topology of the flux tubes. We analyze the
phenomenological support of those scenarios and their observational
implications. Our investigations hint a rich low lying glueball spectrum.Comment: 11 pages: New title, figure, table and a more detailed comparison
with experiment
Right unitarity triangles and tri-bimaximal mixing from discrete symmetries and unification
We propose new classes of models which predict both tri-bimaximal lepton
mixing and a right-angled Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle,
alpha approximately 90 degrees. The ingredients of the models include a
supersymmetric (SUSY) unified gauge group such as SU(5), a discrete family
symmetry such as A4 or S4, a shaping symmetry including products of Z2 and Z4
groups as well as spontaneous CP violation. We show how the vacuum alignment in
such models allows a simple explanation of alpha approximately 90 degrees by a
combination of purely real or purely imaginary vacuum expectation values (vevs)
of the flavons responsible for family symmetry breaking. This leads to quark
mass matrices with 1-3 texture zeros that satisfy the phase sum rule and lepton
mass matrices that satisfy the lepton mixing sum rule together with a new
prediction that the leptonic CP violating oscillation phase is close to either
0, 90, 180, or 270 degrees depending on the model, with neutrino masses being
purely real (no complex Majorana phases). This leads to the possibility of
having right-angled unitarity triangles in both the quark and lepton sectors.Comment: 29 pages, 4 figures, version to be published in NP
Universal spectral correlations in interacting chaotic few-body quantum systems
The emergence of random matrix spectral correlations in interacting quantum
systems is a defining feature of quantum chaos. We study such correlations in
terms of the spectral form factor in interacting chaotic few- and many-body
systems, modeled by suitable random-matrix ensembles, and obtain exact results
for large Hilbert space dimensions. The transition of the spectral form factor
from the non-interacting to the strongly interacting case can be described as a
simple combination of these two limiting cases, which we confirm by extensive
numerical studies in few-body systems. This transition is universally governed
by a single scaling parameter. Moreover, our approach accurately captures
spectral correlations in actual physical system, which we demonstrate for
coupled kicked rotors.Comment: 6 pages, 4 figures, merged into arXiv:2302.0995
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