2,382 research outputs found
Mass Hierarchy, Mixing, CP-Violation and Higgs Decay---or Why Rotation is Good for Us
The idea of a rank-one rotating mass matrix (R2M2) is reviewed detailing how
it leads to ready explanations both for the fermion mass hierarchy and for the
distinctive mixing patterns between up and down fermion states, which can be
and have been tested against experiment and shown to be fully consistent with
existing data. Further, R2M2 is seen to offer, as by-products: (i) a new
solution of the strong CP problem in QCD by linking the theta-angle there to
the Kobayashi-Maskawa CP-violating phase in the CKM matrix, and (ii) some novel
predictions of possible anomalies in Higgs decay observable in principle at the
LHC. A special effort is made to answer some questions raised.Comment: 47 pages, 9 figure
A Nonabelian Yang-Mills Analogue of Classical Electromagnetic Duality
The classic question of a nonabelian Yang-Mills analogue to electromagnetic
duality is here examined in a minimalist fashion at the strictly 4-dimensional,
classical field and point charge level. A generalisation of the abelian Hodge
star duality is found which, though not yet known to give dual symmetry,
reproduces analogues to many dual properties of the abelian theory. For
example, there is a dual potential, but it is a 2-indexed tensor
of the Freedman-Townsend type. Though not itself functioning as such,
gives rise to a dual parallel transport, , for the
phase of the wave function of the colour magnetic charge, this last being a
monopole of the Yang-Mills field but a source of the dual field. The standard
colour (electric) charge itself is found to be a monopole of .
At the same time, the gauge symmetry is found doubled from say to
. A novel feature is that all equations of motion,
including the standard Yang-Mills and Wong equations, are here derived from a
`universal' principle, namely the Wu-Yang (1976) criterion for monopoles, where
interactions arise purely as a consequence of the topological definition of the
monopole charge. The technique used is the loop space formulation of Polyakov
(1980).Comment: We regret that, due to a technical hitch, parts of the reference list
were mixed up. This is the corrected version. We apologize to the authors
whose papers were misquote
ELUCID V. Lighting dark matter halos with galaxies
In a recent study, using the distribution of galaxies in the north galactic
pole of SDSS DR7 region enclosed in a 500\mpch box, we carried out our ELUCID
simulation (Wang et al. 2016, ELUCID III). Here we {\it light} the dark matter
halos and subhalos in the reconstructed region in the simulation with galaxies
in the SDSS observations using a novel {\it neighborhood} abundance matching
method. Before we make use of thus established galaxy-subhalo connections in
the ELUCID simulation to evaluate galaxy formation models, we set out to
explore the reliability of such a link. For this purpose, we focus on the
following a few aspects of galaxies: (1) the central-subhalo luminosity and
mass relations; (2) the satellite fraction of galaxies; (3) the conditional
luminosity function (CLF) and conditional stellar mass function (CSMF) of
galaxies; and (4) the cross correlation functions between galaxies and the dark
matter particles, most of which are measured separately for all, red and blue
galaxy populations. We find that our neighborhood abundance matching method
accurately reproduces the central-subhalo relations, satellite fraction, the
CLFs and CSMFs and the biases of galaxies. These features ensure that thus
established galaxy-subhalo connections will be very useful in constraining
galaxy formation processes. And we provide some suggestions on the three levels
of using the galaxy-subhalo pairs for galaxy formation constraints. The
galaxy-subhalo links and the subhalo merger trees in the SDSS DR7 region
extracted from our ELUCID simulation are available upon request.Comment: 18 pages, 13 figures, ApJ accepte
Fashion, Cooperation, and Social Interactions
Fashion plays such a crucial rule in the evolution of culture and society
that it is regarded as a second nature to the human being. Also, its impact on
economy is quite nontrivial. On what is fashionable, interestingly, there are
two viewpoints that are both extremely widespread but almost opposite:
conformists think that what is popular is fashionable, while rebels believe
that being different is the essence. Fashion color is fashionable in the first
sense, and Lady Gaga in the second. We investigate a model where the population
consists of the afore-mentioned two groups of people that are located on social
networks (a spatial cellular automata network and small-world networks). This
model captures two fundamental kinds of social interactions (coordination and
anti-coordination) simultaneously, and also has its own interest to game
theory: it is a hybrid model of pure competition and pure cooperation. This is
true because when a conformist meets a rebel, they play the zero sum matching
pennies game, which is pure competition. When two conformists (rebels) meet,
they play the (anti-) coordination game, which is pure cooperation. Simulation
shows that simple social interactions greatly promote cooperation: in most
cases people can reach an extraordinarily high level of cooperation, through a
selfish, myopic, naive, and local interacting dynamic (the best response
dynamic). We find that degree of synchronization also plays a critical role,
but mostly on the negative side. Four indices, namely cooperation degree,
average satisfaction degree, equilibrium ratio and complete ratio, are defined
and applied to measure people's cooperation levels from various angles. Phase
transition, as well as emergence of many interesting geographic patterns in the
cellular automata network, is also observed.Comment: 21 pages, 12 figure
Real Scalar Field Scattering with Polynomial Approximation around Schwarzschild-de Sitter Black-hole
As one of the fitting methods, the polynomial approximation is effective to
process sophisticated problem. In this paper, we employ this approach to handle
the scattering of scalar field around the Schwarzschild-de Sitter black-hole.
The complex relationship between tortoise coordinate and radial coordinate is
replaced by the approximate polynomial. The Schrdinger-like equation,
the real boundary conditions and the polynomial approximation construct a full
Sturm-Liouville type problem. Then this boundary value problem can be solved
numerically according to two limiting cases: the first one is the Nariai
black-hole whose horizons are close to each other, the second one is when the
horizons are widely separated. Compared with previous results (Brevik and
Tian), the field near the event horizon and cosmological horizon can have a
better description.Comment: revtex4 source file, 11 pages, 8 figure
Towards a Gravitational Analog to S-duality in Non-abelian Gauge Theories
For non-abelian non-supersymmetric gauge theories, generic dual theories have
been constructed. In these theories the couplings appear inverted. However,
they do not possess a Yang-Mills structure but rather are a kind of non-linear
sigma model. It is shown that for a topological gravitational model an analog
to this duality exists.Comment: LaTeX, 14 pages, no figures, minor correction
Pursuing Gravitational S-Duality
Recently a strong-weak coupling duality in non-abelian non-supersymmetric
theories in four dimensions has been found. An analogous procedure is reviewed,
which allows to find the `dual action' to the gauge theory of dynamical gravity
constructed by the MacDowell-Mansouri model plus the superposition of a
term.Comment: Invited paper to appear in the special issue of the `Journal of
Chaos, Solitons and Fractals' on: "Superstrings, M,F,S,... Theory" (M.S. El
Naschie and C. Castro, editors), 19 pages, LaTeX file, no figure
Contribution of Inelastic Rescatterring to Decays
We discuss multichannel inelastic rescatterring effects in B decays into a
pair of pseudoscalar mesons ( or ). In agreement
with short-distance models it is assumed that initially meson decays
dominantly into jet-like states composed of two flying-apart low-mass
resonances which rescatter into . Since from all S-matrix
elements involving only some () contribute to the
final state rescatterring, the latter is treated as a correction only. The
rescatterring of resonance pair into the final state is assumed
to proceed through Regge exchange. Although effects due to a single
intermediate state are small, it is shown that the combined effect of
all such states should be large. In particular, amplitudes of B decays into
become significantly larger than those estimated through
short-distance penguin diagrams, to the point of being comparable to the amplitudes.Comment: 25 LaTeX pages, 6 figures in one .ps fil
DCE-MRI for pre-treatment prediction and post-treatment assessment of treatment response in sites of squamous cell carcinoma in the head and neck
Background and Purpose It is important to identify patients with head and neck squamous cell carcinoma (SCC) who fail to respond to chemoradiotherapy so that they can undergo post-treatment salvage surgery while the disease is still operable. This study aimed to determine the diagnostic performance of dynamic contrast enhanced (DCE)-MRI using a pharmacokinetic model for pre-treatment predictive imaging, as well as post-treatment diagnosis, of residual SCC at primary and nodal sites in the head and neck. Material and Methods Forty-nine patients with 83 SCC sites (primary and/or nodal) underwent pre-treatment DCEMRI, and 43 patients underwent post-treatment DCE-MRI, of which 33 SCC sites had a residual mass amenable to analysis. Pre-treatment, post-treatment and %change in the mean Ktrans, kep, ve and AUGC were obtained from SCC sites. Logistic regression was used to correlate DCE parameters at each SCC site with treatment response at the same site, based on clinical outcome at that site at a minimum of two years. Results None of the pre-treatment DCE-MRI parameters showed significant correlations with SCC site failure (SF) (29/83 sites) or site control (SC) (54/83 sites). Post-treatment residual masses with SF (14/33) had significantly higher kep (p = 0.05), higher AUGC (p = 0.02), and lower % reduction in AUGC (p = 0.02), than residual masses with SC (19/33), with the% change in AUGC remaining significant on multivariate analysis. Conclusion Pre-treatment DCE-MRI did not predict which SCC sites would fail treatment, but post-treatment DCE-MRI showed potential for identifying residual masses that had failed treatment
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