429,780 research outputs found
Neutrino, Lepton, and Quark Masses in Supersymmetry
The recently proposed model of neutrino mass with no new physics beyond the
TeV energy scale is shown to admit a natural and realistic supersymmetric
realization, when combined with another recently proposed model of quark masses
in the context of a softly broken U(1) symmetry. Four Higgs doublets are
required, but two must have masses at the TeV scale. New characteristic
experimental predictions of this synthesis are discussed.Comment: 7 pages, no figur
A Bi-Hamiltonian Formulation for Triangular Systems by Perturbations
A bi-Hamiltonian formulation is proposed for triangular systems resulted by
perturbations around solutions, from which infinitely many symmetries and
conserved functionals of triangular systems can be explicitly constructed,
provided that one operator of the Hamiltonian pair is invertible. Through our
formulation, four examples of triangular systems are exhibited, which also show
that bi-Hamiltonian systems in both lower dimensions and higher dimensions are
many and varied. Two of four examples give local 2+1 dimensional bi-Hamiltonian
systems and illustrate that multi-scale perturbations can lead to
higher-dimensional bi-Hamiltonian systems.Comment: 16 pages, to appear in J. Math. Phy
Voltage regulation considerations for the design of hybrid distribution transformers
The future substation depends on finding a way to mitigate the effects of the drawbacks of the conventional legacy by employing the efficiency of the solid state switches [1]. This paper discusses the considerations of designing a distribution transformer that provides additional functions in regulating the voltage and controlling the reactive power that is injected in the distribution network, using a fractional rated converter attached partially with the windings of the transformer. This approach aims mainly to enhance the unit with more flexibility in controlling the voltage at the last mile of the network, in order to decrease the losses and meet the future expectations for low voltage networks modifications, and that by using a power electronic (PE) approach has less losses and more functionality (depending on the reliability of transformer and intelligence of PE). The design of a hybrid distribution transformer is detailed and its functionality in regulating the voltage is discussed as a combination between the features of one of the most reliable network devices, the transformer, and the effect of PE existence with less losses in both switching and conduction losses. Reduced ratings PE are used in this approach, whereby the solid state switches are controlled according to the immediate need for voltage control in low voltage (LV) networks
Information complexity of the AND function in the two-Party, and multiparty settings
In a recent breakthrough paper [M. Braverman, A. Garg, D. Pankratov, and O.
Weinstein, From information to exact communication, STOC'13] Braverman et al.
developed a local characterization for the zero-error information complexity in
the two party model, and used it to compute the exact internal and external
information complexity of the 2-bit AND function, which was then applied to
determine the exact asymptotic of randomized communication complexity of the
set disjointness problem.
In this article, we extend their results on AND function to the multi-party
number-in-hand model by proving that the generalization of their protocol has
optimal internal and external information cost for certain distributions. Our
proof has new components, and in particular it fixes some minor gaps in the
proof of Braverman et al
Postpartum Mental Health among Young Women
Background: A number of studies have highlighted the physical health problems associated with adolescent pregnancy in Saudi Arabia , However there were few studies dealing with the postpartum psychiatric disorders .The study aims to determine the prevalence of postpartum psychological distress and to evaluate the associated risk factors in a sample of primigravid young women in Al Ahsa region, Saudi Arabia. Methods: We assessed the prevalence of postnatal mental health in 190 young mothers attending the maternity hospital using general health questionnaire. We also assessed the relationship between socio-demographic, psychiatric and obstetric risk factors and the mental health. Results: The percent of women with psychological distress was 35.2%. Significant risk of psychological distress was associated with several socio-demographic, psychiatric and obstetric risk factors. Only four items were found to be significant predictors of postpartum psychological distress; low family income, poor husband support, birth of female baby and gestational diabetes. Conclusions: These results highlighted importance of screening for psychological distress and its associated risk factors in the implementation of proper perinatal care for the pregnant Saudi adolescents
The Lepton-Number-Violating Decays of and Mesons Induced by the Doubly Charged Higgs Boson
The lepton-number-violating decays of and mesons induced
by the doubly charged Higgs boson have been studied. It is found that although
the yielded results of the branch ratio are much smaller than the present
limits from the data they are consistent with the previous conclusions
calculated in the framwork of relativistic quark model where the processes
happened via the light Majorana neutrinos.Comment: version to appear in PR
New "Square Root" Model of Lepton Family Cyclic Symmetry
Following the newly formulated notion of form invariance of the neutrino mass
matrix, a complete model of leptons is constructed. It is based on a specific
unitary 3 X 3 matrix U in family space, such that U^2 is the simple discrete
symmetry nu_e to -nu_e, nu_mu to nu_tau. Thus U also generates the cyclic group
Z_4. The charged-lepton mass matrix is nearly diagonal while the neutrino mass
matrix is of the form suitable for explaining maximal (large) mixing in
atmospheric (solar) neutrino oscillations in the context of three nearly
degenerate neutrino masses. Observable lepton flavor violation is predicted.
Quarks may be treated in the same way as the charged leptons.Comment: 10 pages, no figur
Nearly Mass-Degenerate Majorana Neutrinos: Double Beta Decay and Neutrino Oscillations
Assuming equal tree-level Majorana masses for the standard-model neutrinos,
either from the canonical seesaw mechanism or from a heavy scalar triplet, I
discuss how their radiative splitting may be relevant to neutrinoless double
beta decay and neutrino oscillations.Comment: 12 pages, including 4 figures, talk at NANP9
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