31,787 research outputs found
CP Violation in Predictive Neutrino Mass Structures
We study the CP violation effects from two types of neutrino mass matrices
with (i) , and (ii) , which can
be realized by the high dimensional lepton number violating operators and , respectively. In (i), the neutrino mass spectrum is in
the normal ordering with the lightest neutrino mass within the range
. Furthermore, for a given
value of , there are two solutions for the two Majorana phases
and , whereas the Dirac phase is arbitrary.
For (ii), the parameters of , , , and
can be completely determined. We calculate the CP violating asymmetries in
neutrino-antineutrino oscillations for both mass textures of (i) and (ii),
which are closely related to the CP violating Majorana phases.Comment: 17 pages, 4 figures, revised version accepted by EPJ
X-ray Line from the Dark Transition Electric Dipole
We study a two-component dark matter (DM) model in which the two Majorana
fermionic DM components with nearly degenerate masses are stabilized by an
symmetry and interact with the right-handed muon and tau only via real
Yukawa couplings, together with an additional -odd singly-charged scalar.
In this setup, the decay from the heavy DM to the lighter one via the
transition electric dipole yields the 3.55 keV X-ray signal observed recently.
The Yukawa couplings in the dark sector are assumed to be hierarchical, so that
the observed DM relic abundance can be achieved with the leading s-wave
amplitudes without a fine-tuning. We also consider the constraints from flavor
physics, DM direct detections and collider searches, respectively.Comment: 16 pages, 4 figures, revised version accepted for publication in JHE
High quality epitaxial ZnSe and the relationship between electron mobility and photoluminescence characteristics
High quality epitaxial layers of nominally undoped ZnSe have been grown by metalorganic chemical vapor deposition at low temperature (325 °C) and pressure (30 Torr), using dimethylzinc and hydrogen selenide. All layers were unintentionally doped n type with net carrier concentrations of 6.4×10^(14)–1.5×10^(16) cm^(−3) and exhibited very high mobility at room temperature (up to 500 cm2/V s) as well as at 77 K, where the measured value of 9250 cm^2/V s is the highest so far reported for vapor phase growth. Additional evidence for the high quality of the material is provided by photoluminescence. Experimental results indicate a correlation between the photoluminescence characteristics and the electrical properties that may be useful in assessing the quality of ZnSe films
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