1,876 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
On the Corner Elements of the CKM and PMNS Matrices
Recent experiments show that the top-right corner element () of the
PMNS, like that () of the CKM, matrix is small but nonzero, and suggest
further via unitarity that it is smaller than the bottom-left corner element
(), again as in the CKM case (). An attempt in
explaining these facts would seem an excellent test for any model of the mixing
phenomenon. Here, it is shown that if to the assumption of a universal rank-one
mass matrix, long favoured by phenomenologists, one adds that this matrix
rotates with scale, then it follows that (A) by inputting the mass ratios
, and , (i) the corner elements are
small but nonzero, (ii) , , (iii)
estimates result for the ratios and , and
(B) by inputting further the experimental values of and
, (iv) estimates result for the values of the corner elements
themselves. All the inequalities and estimates obtained are consistent with
present data to within expectation for the approximations made.Comment: 9 pages, 2 figures, updated with new experimental data and more
detail
Gravity and Large-Scale Non-local Bias
The relationship between galaxy and matter overdensities, bias, is most often
assumed to be local. This is however unstable under time evolution, we provide
proofs under several sets of assumptions. In the simplest model galaxies are
created locally and linearly biased at a single time, and subsequently move
with the matter (no velocity bias) conserving their comoving number density (no
merging). We show that, after this formation time, the bias becomes unavoidably
non-local and non-linear at large scales. We identify the non-local
gravitationally induced fields in which the galaxy overdensity can be expanded,
showing that they can be constructed out of the invariants of the deformation
tensor (Galileons). In addition, we show that this result persists if we
include an arbitrary evolution of the comoving number density of tracers. We
then include velocity bias, and show that new contributions appear, a dipole
field being the signature at second order. We test these predictions by
studying the dependence of halo overdensities in cells of fixed matter density:
measurements in simulations show that departures from the mean bias relation
are strongly correlated with the non-local gravitationally induced fields
identified by our formalism. The effects on non-local bias seen in the
simulations are most important for the most biased halos, as expected from our
predictions. The non-locality seen in the simulations is not fully captured by
assuming local bias in Lagrangian space. Accounting for these effects when
modeling galaxy bias is essential for correctly describing the dependence on
triangle shape of the galaxy bispectrum, and hence constraining cosmological
parameters and primordial non-Gaussianity. We show that using our formalism we
remove an important systematic in the determination of bias parameters from the
galaxy bispectrum, particularly for luminous galaxies. (abridged)Comment: 26 pages, 9 figures. v2: improved appendix
N-String Vertices in String Field Theory
We give the general form of the vertex corresponding to the interaction of an
arbitrary number of strings. The technique employed relies on the ``comma"
representation of String Field Theory where string fields and interactions are
represented as matrices and operations between them such as multiplication and
trace. The general formulation presented here shows that the interaction vertex
of N strings, for any arbitrary N, is given as a function of particular
combinations of matrices corresponding to the change of representation between
the full string and the half string degrees of freedom.Comment: 22 pages, A4-Latex (latex twice), FTUV IFI
A first test of the framed standard model against experiment
The framed standard model (FSM) is obtained from the standard model by incorporating, as field variables, the frame vectors (vielbeins) in internal symmetry space. It gives the standard Higgs boson and 3 generations of quarks and leptons as immediate consequences. It gives moreover a fermion mass matrix of the form: m = mT alpha alpha dagger, where alpha is a vector in generation space independent of the fermion species and rotating with changing scale, which has already been shown to lead, generically, to up-down mixing, neutrino oscillations and mass hierarchy. In this paper, pushing the FSM further, one first derives to 1-loop order the RGE for the rotation of alpha, and then applies it to fit mass and mixing data as a first test of the model. With 7 real adjustable parameters, 18 measured quantities are fitted, most (12) to within experimental error or to better than 0.5 percent, and the rest (6) not far off. (A summary of this fit can be found in Table 2 of this paper.) Two notable features, both generic to FSM, not just specific to the fit, are: (i) that a theta-angle of order unity in the instanton term in QCD would translate via rotation into a Kobayashi-Maskawa phase in the CKM matrix of about the observed magnitude (J similar to 10(-5)), (ii) that it would come out correctly that m(u) > m(b), m(c) >> m(s). Of the 18 quantities fitted, 12 are deemed independent in the usual formulation of the standard model. In fact, the fit gives a total of 17 independent parameters of the standard model, but 5 of these have not been measured by experiment
Developing the Framed Standard Model
The framed standard model (FSM) suggested earlier, which incorporates the
Higgs field and 3 fermion generations as part of the framed gauge theory
structure, is here developed further to show that it gives both quarks and
leptons hierarchical masses and mixing matrices akin to what is experimentally
observed. Among its many distinguishing features which lead to the above
results are (i) the vacuum is degenerate under a global symmetry which
plays the role of fermion generations, (ii) the fermion mass matrix is
"universal", rank-one and rotates (changes its orientation in generation space)
with changing scale , (iii) the metric in generation space is
scale-dependent too, and in general non-flat, (iv) the theta-angle term in the
QCD action of topological origin gets transformed into the CP-violating phase
of the CKM matrix for quarks, thus offering at the same time a solution to the
strong CP problem.Comment: 53 Page
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
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