4,757 research outputs found
The effects of Majorana phases in three-generation neutrinos
Neutrino-oscillation solutions for the atmospheric neutrino anomaly and the
solar neutrino deficit can determine the texture of the neutrino mass matrix
according to three types of neutrino mass hierarchies as Type A: ,
Type B: , and Type C: , where is the -th generation neutrino absolute mass. The
relative sign assignments of neutrino masses in each type of mass hierarchies
play the crucial roles for the stability against quantum corrections. Actually,
two physical Majorana phases in the lepton flavor mixing matrix connect among
the relative sign assignments of neutrino masses. Therefore, in this paper we
analyze the stability of mixing angles against quantum corrections according to
three types of neutrino mass hierarchies (Type A, B, C) and two Majorana
phases. Two phases play the crucial roles for the stability of the mixing
angles against the quantum corrections.Comment: LaTeX2e, 15 pages, 8 figure
Energy-Scale Dependence of the Lepton-Flavor-Mixing Matrix
We study an energy-scale dependence of the lepton-flavor-mixing matrix in the
minimal supersymmetric standard model with the effective dimension-five
operators which give the masses of neutrinos. We analyze the renormalization
group equations of kappa_{ij}s which are coefficients of these effective
operators under the approximation to neglect the corrections of O(\kappa^2). As
a consequence, we find that all phases in do not depend on the
energy-scale, and that only n_g-1 (n_g: generation number) real independent
parameters in the lepton-flavor-mixing matrix depend on the energy-scale.Comment: 6 pages, no figur
The effect of Majorana phase in degenerate neutrinos
There are physical Majorana phases in the lepton flavor mixing matrix when
neutrinos are Majorana fermions. In the case of two degenerate neutrinos, the
physical Majorana phase plays the crucial role for the stability of the maximal
flavor mixing between the second and the third generations against quantum
corrections. The physical Majorana phase of guarantees the maximal mixing
to be stable against quantum corrections, while the Majorana phase of zero lets
the maximal mixing be spoiled by quantum corrections when neutrino masses are
of O(eV). The continuous change of the Majorana phase from to 0 makes the
maximal mixing be spoiled by quantum corrections with O(eV) degenerate neutrino
masses. On the other hand, when there is the large mass hierarchy between
neutrinos, the maximal flavor mixing is not spoiled by quantum corrections
independently of the Majorana phase.Comment: 7 pages, 1 figures, LaTe
Method for producing heat-resistant semi-inorganic compounds
The method for producing a heat resistant, semi-inorganic compound is discussed. Five examples in which various alcohols, phenols, and aromatic carbonic acids are used to test heat resistance and solubility are provided
Interspecific differences in the larval performance of Pieris butterflies (Lepidoptera: Pieridae) are associated with differences in the glucosinolate profiles of host plants
The tremendous diversity of plants and herbivores has arisen from a coevolutionary relationship characterized by plant defense and herbivore counter adaptation. Pierid butterfly species feed on Brassicales plants that produce glucosinolates as a chemical deterrent against herbivory. In turn, the larvae of pierids have nitrile specifier proteins (NSPs) that are expressed in their gut and disarm glucosinolates. Pierid butterflies are known to have diversified in response to glucosinolate diversification in Brassicales. Therefore, each pierid species is expected to have a spectrum of host plants characterized by specific glucosinolate profiles. In this study, we tested whether the larval performance of different Pieris species, a genus in Pieridae (Lepidoptera: Pieridae), was associated with plant defense traits of putative host plants. We conducted feeding assays using larvae of three Pieris species and 10 species of the Brassicaceae family possessing different leaf physical traits and glucosinolate profile measurements. The larvae of Pieris rapae responded differently in the feeding assays compared with the other two Pieris species. This difference was associated with differences in glucosinolate profiles but not with variations in physical traits of the host plants. This result suggests that individual Pieris species are adapted to a subset of glucosinolate profiles within the Brassicaceae. Our results support the idea that the host ranges of Pieris species depend on larval responses to glucosinolate diversification in the host species, supporting the hypothesis of coevolution between butterflies and host plants mediated by the chemical arms race
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