10,822 research outputs found
Protecting unparticles from the MSSM Higgs sector
We construct a model of an unparticle sector consisting of a supersymmetric
SU(N) gauge theory with the number of flavors in the Seiberg conformal window.
We couple this sector to the MSSM via heavy messengers. The resulting low
energy theory has a Higgs coupling to unparticles. The Higgs vev drives the
hidden Seiberg sector to a new conformal fixed point. The coupling to the Higgs
mediates supersymmetry breaking to the Seiberg sector, and breaks conformal
invariance at a lower scale. The low energy theory contains light stable and
metastable mesons. Higgs decay into this sector gives signatures which are
similar to those of "hidden valley" models. Decays of the lightest superpartner
of standard model particles into the hidden sector reveal potentially
observable unparticle kinematics.Comment: References added. 11 pages, 4 figure
The current problems of the minimal SO(10) GUT and their solutions
This talk consists of two parts. In part I we review how the minimal
renormalizable supersymmetric SO(10) model, an SO(10) framework with only one
10 and one 126 Higgs multiplets in the Yukawa sector, is attractive because of
its highly predictive power. Indeed it not only gives a consistent predictions
on neutrino oscillation data but also gives reasonable and interesting values
for leptogenesis, LFV, muon g-2, neutrinoless double beta decay etc. However,
this model suffers from problems related to running of gauge couplings. The
gauge coupling unification may be spoiled due to the presence of Higgs
multiplets much lighter than the grand unification (GUT) scale. In addition,
the gauge couplings blow up around the GUT scale because of the presence of
Higgs multiplets of large representations. In part II we consider the minimal
SO(10) model in the warped extra dimension and show a possibility to solve
these problems.Comment: 15 pages, 7 figures, Talk given at the International Workshop on
Neutrino Masses and Mixings Toward Unified Understanding of Quarks and Lepton
Mass Matrices, held at University of Shizuoka on December 17-19, 200
NMR characterization of spin-1/2 alternating antiferromagnetic chains in the high-pressure phase of (VO)2P2O7
Local-susceptibility measurements via the NMR shifts of P and V
nuclei in the high-pressure phase of (VO)PO confirmed the
existence of a unique alternating antiferromagnetic chain with a zero-field
spin gap of 34 K. The P nuclear spin-lattice relaxation rate scales with
the uniform spin susceptibility below about 15 K which shows that the
temperature dependence of both the static and dynamical spin susceptibilities
becomes identical at temperatures not far below the spin-gap energy.Comment: 6 pages, 5 figures; To be published in J. Phys. Condens. Matte
Magnetization Process of High Anisotropy Copt Nanosized Dots
The magnetization reversal process of the CoPt dot was investigated in this paper. It was observed that the magnetization reversal of the dot was initiated by the rotation process of a nucleus with the volume of (17 nm)/sup 3/
Constraints on unparticle long range forces from big bang nucleosynthesis bounds on the variation of the gravitational coupling
We use big bang nucleosynthesis bounds on the variation of the gravitational
coupling to derive constraints on the strength of the deviation from the
gravitational inverse-square law due to tensor and vector unparticle exchange.Comment: 4 pages, 3 figures, change in the title and other minor changes to
match version published in Physical Review
On Phase Transition of -Type Crystals by Cluster Variation Method
The Cluster Variation Method (CVM) is applied to the Ishibashi model for
ammonium dihydrogen phosphate () of a typical hydrogen
bonded anti-ferroelectric crystal. The staggered and the uniform susceptibility
without hysteresis are calculated at equilibrium. On the other hand, by making
use of the natural iteration method (NIM) for the CVM, hysteresis phenomena of
uniform susceptibility versus temperature observed in experiments is well
explained on the basis of local minimum in Landau type variational free energy.
The polarization curves against the uniform field is also calculated.Comment: 14 pages, 10 figure
Hawking radiation of unparticles
Unparticle degrees of freedom, no matter how weakly coupled to the standard
model particles, must affect the evolution of a black hole, which thermally
decays into all available degrees of freedom. We develop a method for
calculating the grey-body factors for scalar unparticles for 3+1 and higher
dimensional black holes. We find that the power emitted in unparticles may be
quite different from the power emitted in ordinary particles. Depending on the
parameters in the model, unparticles may become the dominant channel. This is
of special interest for small primordial black holes and also in models with
low scale quantum gravity where the experimental signature may significantly be
affected. We also discuss the sensitivity of the results on the (currently
unknown) unparticle normalization.Comment: Calculations for different normalization of unparticles included,
discussion expanded, version published in Phys. Rev.
Response of convection electric fields in the magnetosphere to IMF orientation change
[1] The transient response of convection electric fields in the inner magnetosphere to southward turning of the interplanetary magnetic field (IMF) is investigated using in‐situ electric field observations by the CRRES and Akebono spacecraft. Electric fields earthward of the inner edge of the electron plasma sheet show quick responses simultaneously with change in ionospheric electric fields, which indicates the arrival of the first signal related to southward turning. A coordinated observation of the electric field by the CRRES and Akebono spacecraft separated by 5 RE reveals a simultaneous increase in the dawn‐dusk electric field in a wide region of the inner magnetosphere. A quick response associated with the southward turning of the IMF is also identified in in‐situ magnetic fields. It indicates that the southward turning of the IMF initiates simultaneous (less than 1 min) enhancements of ionospheric electric fields, convection electric fields in the inner magnetosphere, and the ring or tail current and region 2 FACs. In contrast, a quick response of convection electric fields is not identified in the electron plasma sheet. A statistical study using 161 events of IMF orientation change in 1991 confirms a prompt response within 5 min for 80% of events earthward of the electron plasma sheet, while a large time lag of more than 30 min is identified in electric fields in the electron plasma sheet. The remarkable difference in the response of electric fields indicates that electric fields in the electron plasma sheet are weakened by high conductance in the magnetically conjugated auroral ionosphere.https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2009JA014277https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2009JA014277Published versio
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