1,761 research outputs found
New physics for muon anomalous magnetic moment and its electroweak precision analysis
About 3 sigma deviation from the standard model prediction of muon anomalous
magnetic moment (muon g-2) has been reported. We consider new physics beyond
the standard model which has new Yukawa interactions with muon. We compute new
contributions to muon g-2 and corrections to electroweak observables, and show
the consistent region of parameter space. We find that in a simple model where
the chirality flip of muon occurs only in the external muon line in one-loop
muon g-2 diagrams, it is necessary to introduce the relatively large new Yukawa
coupling and the electroweak scale new particles. On the other hand, in a model
where the chirality flip can occur in the internal fermion line of one loop
muon g-2 diagrams, we can obtain favorable g-2 contributions without large
Yukawa coupling, and they are consistent with the precision electroweak
observables. Finally, we discuss effects of new particles for muon g-2 on the
Higgs boson decay h to 2 photons and direct productions of these particles at
the LHC experiment.Comment: 31 pages, 20 figure
Residual stress field of HIPed silicon nitride rolling elements
The residual stress field of HIPed Si3N4 rolling elements were studied. Two kinds of HIPed Si3N4 ball blanks self-finished at different nominal lapping loads ranging from 1.3 to 10.87 kgf/ball and four kinds of commercially finished 1/2 in (12.7 mm) HIPed Si3N4 balls before, during and after RCF tests were investigated. The experimental results showed that in the finishing process of HIPed Si3N4 rolling elements. the surface and subsurface compressive residual stress induced is proportional to the lapping load applied. There was initially a high compressive residual stress layer on the HIPed Si3N4 ball blanks and this layer is mostly removed during the finishing process. During the rolling contact fatigue process of HIPed Si3N4 rolling elements, the residual stresses on the rolling track will change dramatically as RCF proceeds
Exact Event Rates of Lepton Flavor Violating Processes in Supersymmetric SU(5) Model
Event rates of various lepton flavor violating processes in the minimal
supersymmetric SU(5) model are calculated, using exact formulas which include
Yukawa vertices of lepton-slepton-Higgsino. We find subtlety in evaluating
event rates due to partial cancellation between diagrams. This cancellation
typically reduces the event rates significantly, and the size of the reduction
strongly depends on superparticle mass spectrum.Comment: 11pages, 8 figures. Fig.5 where the mu-e conversion rates in nuclei
was shown was incorrect due to an error in our numerical computation.It is
replaced in this corrected version. All conclusions remain unchange
Localization problem of the quasiperiodic system with the spin orbit interaction
We study one dimensional quasiperiodic system obtained from the tight-binding
model on the square lattice in a uniform magnetic field with the spin orbit
interaction. The phase diagram with respect to the Harper coupling and the
Rashba coupling are proposed from a number of numerical studies including a
multifractal analysis. There are four phases, I, II, III, and IV in this order
from weak to strong Harper coupling. In the weak coupling phase I all the wave
functions are extended, in the intermediate coupling phases II and III mobility
edges exist, and accordingly both localized and extended wave functions exist,
and in the strong Harper coupling phase IV all the wave functions are
localized. Phase I and Phase IV are related by the duality, and phases II and
III are related by the duality, as well. A localized wave function is related
to an extended wave function by the duality, and vice versa. The boundary
between phases II and III is the self-dual line on which all the wave functions
are critical. In the present model the duality does not lead to pure spectra in
contrast to the case of Harper equation.Comment: 10 pages, 11 figure
Peningkatan Pemahaman Tentang Pentingnya Mengenali HIV AIDS Sejak Dini di SMP N 8 Kediri
Kejadian HIV/AIDS merupakan permasalahan global yang hingga saat ini masih belum terselesaikan, termasuk di Indonesia. Kasus tertinggi terjadi pada kelompok umur 20-49 tahun yang mengindikasikan pada usia remaja (15-25 tahun) mereka sudah mengidap HIV. Penyebab tingginya kejadian HIV/AIDS pada remaja dipengaruhi banyak hal diantaranya kurangnya pengetahuan mereka tentang HIV/AIDS. Laporan ini bertujuan untuk mengetahui pengaruh penyuluhan terhadap pengetahuan dan sikap siswa siswi SMPN 8 Kediri. Laporan ini menggunakan metode presentasi dan diskusi tanya jawab. Hasil penyuluhan menunjukkan siswa maupun siswi yang setelah diberikan penyuluhan menjadi lebih memahami bahayanya HIV/AIDS karena beberapa faktor. Selain itu, antusias mereka dalam mencari informasi lebih dalam mengenai HIV/AIDS juga sangat baik setelah diberikan penyuluhan
Effective Two Higgs Doublets in Nonminimal Supersymmetric Models
The Higgs sectors of supersymmetric extensions of the Standard Model have two
doublets in the minimal version (MSSM), and two doublets plus a singlet in two
others: with (UMSSM) and without (NMSSM) an extra U(1)'. A very concise
comparison of these three models is possible if we assume that the singlet has
a somewhat larger breaking scale compared to the electroweak scale. In that
case, the UMSSM and the NMSSM become effectively two-Higgs-doublet models
(THDM), like the MSSM. As expected, the mass of the lightest CP-even neutral
Higgs boson has an upper bound in each case. We find that in the NMSSM, this
bound exceeds not very much that of the MSSM, unless tan(beta) is near one.
However, the upper bound in the UMSSM may be substantially enhanced.Comment: 8 pages, 1 table, 3 figure
Neutrino mixing and large CP violation in B physics
We show that in see-saw models of neutrino mass a la SUSY SO(10), the
observed large mixing in atmospheric neutrinos naturally leads to large b-s
transitions. If the associated new CP phase turns out to be large, this SUSY
contributions can drastically affect the CP violation in some of the B decay
channels yielding the beta and gamma angles of the unitarity triangle. They can
even produce sizeable CP asymmetries in some decay modes which are not CP
violating in the standard model context. Hence the observed large neutrino
mixing makes observations of low energy SUSY effect in some CP violating decay
channels potentially promising in spite of the agreement between the Standard
Model and data in K and B physics so far.Comment: References adde
Bi-large Neutrino Mixing and Mass of the Lightest Neutrino from Third Generation Dominance in a Democratic Approach
We show that both small mixing in the quark sector and large mixing in the
lepton sector can be obtained from a simple assumption of universality of
Yukawa couplings and the right-handed neutrino Majorana mass matrix in leading
order. We discuss conditions under which bi-large mixing in the lepton sector
is achieved with a minimal amount of fine-tuning requirements for possible
models. From knowledge of the solar and atmospheric mixing angles we determine
the allowed values of sin \theta_{13}. If embedded into grand unified theories,
the third generation Yukawa coupling unification is a generic feature while
masses of the first two generations of charged fermions depend on small
perturbations. In the neutrino sector, the heavier two neutrinos are model
dependent, while the mass of the lightest neutrino in this approach does not
depend on perturbations in the leading order. The right-handed neutrino mass
scale can be identified with the GUT scale in which case the mass of the
lightest neutrino is given as (m_{top}^2/M_{GUT}) sin^2 \theta_{23} sin^2
\theta_{12} in the limit sin \theta_{13} = 0. Discussing symmetries we make a
connection with hierarchical models and show that the basis independent
characteristic of this scenario is a strong dominance of the third generation
right-handed neutrino, M_1, M_2 < 10^{-4} M_3, M_3 = M_{GUT}.Comment: typos correcte
Crystal Field and Dzyaloshinsky-Moriya Interaction in orbitally ordered La_{0.95}Sr_{0.05}MnO_3: An ESR Study
We present a comprehensive analysis of Dzyaloshinsky-Moriya interaction and
crystal-field parameters using the angular dependence of the paramagnetic
resonance shift and linewidth in single crystals of La_{0.95}Sr_{0.05}MnO_3
within the orthorhombic Jahn-Teller distorted phase. The Dzyaloshinsky-Moriya
interaction (~ 1K) results from the tilting of the MnO_6 octahedra against each
other. The crystal-field parameters D and E are found to be of comparable
magnitude (~ 1K) with D ~= -E. This indicates a strong mixing of the |3z^2-r^2>
and |x^2-y^2> states for the real orbital configuration.Comment: 12 pages, 6 figure
Anisotropic Optic Conductivities due to Spin and Orbital Orderings in LaVO3 and YVO3: First-Principles Studies
The anisotropy of low energy (05eV) optical excitations in strongly
correlated transition-metal oxides is closely related to the spin and orbital
orderings. The recent successes of LDA+ method in describing the magnetic
and electronic structures enable us to calculate the optical conductivity from
first-principles. The LaVO and YVO, both of which have
configuration and have various spin and orbital ordered phases at low
temperature, show distinct anisotropy in the optical spectra. The effects of
spin and orbital ordering on the anisotropy are studied in detail based on our
first-principles calculations. The experimental spectra of both compounds at
low temperature phases can be qualitatively explained with our calculations,
while the studies for the intermediate temperature phase of YVO suggest the
substantial persistence of the low temperature phase at elevated temperature.Comment: 6 pages, 3 figures, accepted by PR
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