4,988 research outputs found
Vanishing corrections on the intermediate scale and implications for unification of forces
In two-step breaking of a class of grand unified theories including SO(10),we
prove a theorem showing that the scale where the Pati-Salam gauge
symmetry with parity breaks down to the standard gauge group,has vanishing
corrections due to all sources emerging from higher scales such as
the one-loop and all higher loop effects,the GUT-threshold,gravitational
smearing,and string threshold effects. Implications of such a scale for the
unification of gauge couplings with small Majorana neutrino masses are
discussed.In string inspired SO(10) we show that ,needed for neutrino masses,with the GUT scale can
be realized provided certain particle states in the predicted spectum are
light.Comment: 21 pages, Late
Persistent Mullerian duct syndrome: the hidden normal or abnormal anatomy and the value of laparoscopy
Persistent Mullerian duct syndrome (PMDS) is a rare disorder of male sexual development. It is characterized by the presence of a uterus, fallopian tubes, and upper vagina in an otherwise phenotypically and genotypically normal male. This malformation is usually an incidental finding during the operative treatment of other more common abnormalities such as inguinal hernia or undescended testes. Not uncommonly, it is seen in association with transverse testicular ectopia. This report describes a case of PMDS in association with transverse testicular ectopia diagnosed at the time of laparoscopy for undescended testes. Physicians caring for these patients should be aware of this and surgeons should be familiar with the different surgical options. PMDS should be considered in all cases of bilateral undescended testes. Aspects of diagnosis and management are also discussed. Keywords: inguinal hernia, laparoscopy, persistent mullerian duct syndrome, transverse testicular ectopia, undescended teste
Type II Seesaw Dominance in Non-supersymmetric and Split Susy SO(10) and Proton Life Time
Recently type II seesaw dominance in a supersymmetric SO(10) framework has
been found useful in explaining large solar and atmospheric mixing angles as
well as larger values of while unifying quark and lepton masses.
An important question in these models is whether there exists consistency
between coupling unification and type II seesaw dominance. Scenarios where this
consistency can be demonstrated have been given in a SUSY framework. In this
paper we give examples where type II dominance occurs in SO(10) models without
supersymmetry but with additional TeV scale particles and also in models with
split-supersummetry. Grand unification is realized in a two-step process via
breaking of SO(10) to SU(5) and then to a TeV scale standard model supplemented
by extra fields and an SU(5) Higgs multiplet at a scale about
GeV to give type-II seesaw. The predictions for proton lifetime in
these models are in the range yrs. to yrs.. A number of recent numerical fits to GUT-scale fermion
masses can be accommodated within this model.Comment: 7 pages LaTeX, 3 figures, related areas: hep-ex, hep-th, astro-ph;
Reference added, typo corrected, version to appear in Physical Review
Quark lepton complementarity and renormalization group effects
We consider a scenario for the Quark-Lepton Complementarity relations between
mixing angles in which the bi-maximal mixing follows from the neutrino mass
matrix. According to this scenario in the lowest order the angle \theta_{12} is
\sim 1\sigma (1.5 - 2^\circ) above the best fit point coinciding practically
with the tri-bimaximal mixing prediction. Realization of this scenario in the
context of the seesaw type-I mechanism with leptonic Dirac mass matrices
approximately equal to the quark mass matrices is studied. We calculate the
renormalization group corrections to \theta_{12} as well as to \theta_{13} in
the standard model (SM) and minimal supersymmetric standard model (MSSM). We
find that in large part of the parameter space corrections \Delta \theta_{12}
are small or negligible. In the MSSM version of the scenario the correction
\Delta \theta_{12} is in general positive. Small negative corrections appear in
the case of an inverted mass hierarchy and opposite CP parities of \nu_1 and
\nu_2 when leading contributions to \theta_{12} running are strongly
suppressed. The corrections are negative in the SM version in a large part of
the parameter space for values of the relative CP phase of \nu_1 and \nu_2:
\phi > \pi/2.Comment: version as published in PRD, 14 pages, 12 figure
Neutrino Mixings and Leptonic CP Violation from CKM Matrix and Majorana Phases
The high scale mixing unification hypothesis recently proposed by three of us
(R. N. M., M. K. P. and G. R.) states that if at the seesaw scale, the quark
and lepton mixing matrices are equal then for quasi-degenerate neutrinos,
radiative corrections can lead to large solar and atmospheric mixings and small
reactor angle at the weak scale in agreement with data. Evidence for
quasi-degenerate neutrinos could, within this framework, be interpreted as a
sign of quark-lepton unification at high scale. In the current work, we extend
this model to show that the hypothesis works quite successfully in the presence
of CP violating phases (which were set to zero in the first paper). In the case
where the PMNS matrix is identical to the CKM matrix at the seesaw scale, with
a Dirac phase but no Majorana phase, the low energy Dirac phase is predicted to
be () and leptonic CP-violation parameter and . If on the other hand, the
PMNS matrix is assumed to also have Majorana phases initially, the resulting
theory damps radiative magnification phenomenon for a large range of parameters
but nevertheless has enough parameter space to give the two necessary large
neutrino mixing angles. In this case, one has and as large as which are accessible to long
baseline neutrino oscillation experiments.Comment: 15 pages and 10 figures, typo correcte
A minimal descriptor of an ancestral recombinations graph
<p>Abstract</p> <p>Background</p> <p>Ancestral Recombinations Graph (ARG) is a phylogenetic structure that encodes both duplication events, such as mutations, as well as genetic exchange events, such as recombinations: this captures the (genetic) dynamics of a population evolving over generations.</p> <p>Results</p> <p>In this paper, we identify structure-preserving and samples-preserving core of an ARG <it>G</it> and call it the minimal descriptor ARG of <it>G</it>. Its structure-preserving characteristic ensures that all the branch lengths of the marginal trees of the minimal descriptor ARG are identical to that of <it>G</it> and the samples-preserving property asserts that the patterns of genetic variation in the samples of the minimal descriptor ARG are exactly the same as that of <it>G</it>. We also prove that even an unbounded <it>G</it> has a finite minimal descriptor, that continues to preserve certain (graph-theoretic) properties of <it>G</it> and for an appropriate class of ARGs, our estimate (Eqn 8) as well as empirical observation is that the expected reduction in the number of vertices is exponential.</p> <p>Conclusions</p> <p>Based on the definition of this lossless and bounded structure, we derive local properties of the vertices of a minimal descriptor ARG, which lend itself very naturally to the design of efficient sampling algorithms. We further show that a class of minimal descriptors, that of binary ARGs, models the standard coalescent exactly (Thm 6).</p
Normal, Abby Normal, Prefix Normal
A prefix normal word is a binary word with the property that no substring has
more 1s than the prefix of the same length. This class of words is important in
the context of binary jumbled pattern matching. In this paper we present
results about the number of prefix normal words of length , showing
that for some and
. We introduce efficient
algorithms for testing the prefix normal property and a "mechanical algorithm"
for computing prefix normal forms. We also include games which can be played
with prefix normal words. In these games Alice wishes to stay normal but Bob
wants to drive her "abnormal" -- we discuss which parameter settings allow
Alice to succeed.Comment: Accepted at FUN '1
Predictions for Proton Lifetime in Minimal Non-Supersymmetric SO(10) Models: An Update
We present our best estimates of the uncertainties due to heavy particle
threshold corrections on the unification scale , intermediate scale
and coupling constant Alpha_U in the minimal non-supersymmetric SO(10) models.
Using these , we update the predictions for proton life-time in these models.Comment: UMD-PP-94-117 ( 20 pages;latex; no figures
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