130 research outputs found
Radion stabilization in the presence of Wilson line phase
We study the stabilization of an extra-dimensional radius in the presence of
a Wilson line phase of an extra gauge symmetry on a five-dimensional
space-time, using the effective potential relating both the radion and the
Wilson line phase at the one-loop level. We find that the radion can be
stabilized by the introduction of a small number of fermions.Comment: 12 pages, 5 figures, Comments added. References added. Typo correcte
Finite spin-glass transition of the XY model in three dimensions
A three-dimensional XY spin-glass model is investigated by a
nonequilibrium relaxation method. We have introduced a new criterion for the
finite-time scaling analysis. A transition temperature is obtained by a
crossing point of obtained data. The scaling analysis on the relaxation
functions of the spin-glass susceptibility and the chiral-glass susceptibility
shows that both transitions occur simultaneously. The result is checked by
relaxation functions of the Binder parameters and the glass correlation lengths
of the spin and the chirality. Every result is consistent if we consider that
the transition is driven by the spin degrees of freedom.Comment: 11 pages, 8 figures, incorrect arguments are delete
Determining at the NLC with SUSY Higgs Bosons
We examine the prospects for determining from heavy Higgs scalar
production in the minimal supersymmetric standard model at a future
collider. Our analysis is independent of assumptions of parameter unification,
and we consider general radiative corrections in the Higgs sector. Bounds are
presented for GeV and 1 TeV, several Higgs masses, and a
variety of integrated luminosities. For all cases considered, it is possible to
distinguish low, moderate, and high . In addition, we find stringent
constraints for , and, for some scenarios, also
interesting bounds on high through production. Such
measurements may provide strong tests of the Yukawa unifications in grand
unified theories and make possible highly precise determinations of soft SUSY
breaking mass parameters.Comment: Talk presented by T. Moroi at the SUSY'97 Conference, May 27-31,
Philadelphia, PA, US
KĻ ā Open-source library for the shifted Krylov subspace method of the form (zIāH)x=b
We develop KĻ, an open-source linear algebra library for the shifted Krylov subspace methods. The methods solve a set of shifted linear equations (zkIāH)x(k)=b(k=0,1,2,ā¦) for a given matrix H and a vector b, simultaneously. The leading order of the operational cost is the same as that for a single equation. The shift invariance of the Krylov subspace is the mathematical foundation of the shifted Krylov subspace methods. Applications in materials science are presented to demonstrate the advantages of the algorithm over the standard Krylov subspace methods such as the Lanczos method. We introduce benchmark calculations of (i) an excited (optical) spectrum and (ii) intermediate eigenvalues by the contour integral on the complex plane. In combination with the quantum lattice solver HĪ¦, KĻ can realize parallel computation of excitation spectra and intermediate eigenvalues for various quantum lattice models
No-Scale Scenarios in the Light of New Measurement of Muon Anomalous Magnetic Moment
Supersymmetric contribution to the muon anomalous magnetic moment a_\mu is
discussed in the no-scale-type supersymmetry breaking scenarios. Taking the
correlation between the supersymmetric contributions to a_\mu and Br(b\to
s\gamma), it is shown that the precise measurements of these quantities serve
an important constraint on the relative sign of the gaugino masses; combining
the 2.6-\sigma deviation in a_\mu from the standard-model prediction measured
by the E821 experiment and Br(b\to s\gamma) measured by CLEO, the sign of the
product M_2M_3 is strongly preferred to be positive, where M_2 and M_3 are
SU(2)_L and SU(3)_C gaugino mass parameters, respectively. In particular,
no-scale-type models with universal gaugino masses are in accord with the two
constraints and also with the Higgs mass bound. In addition, it is also shown
that future improvements in the measurements of a_\mu and Br(b\to s\gamma) may
provide serious test of the cases with M_2M_3<0.Comment: 10 pages, 4 figures, published versio
Improvement of the target sensitivity in DECIGO by optimizing its parameters for quantum noise including the effect of diffraction loss
DECIGO is the future Japanese gravitational wave detector in outer space. We
previously set the default design parameters to provide a good target
sensitivity to detect the primordial gravitational waves (GWs). However, the
updated upper limit of the primordial GWs by the Planck observations motivated
us for further optimization of the target sensitivity. Previously, we had not
considered optical diffraction loss due to the very long cavity length. In this
paper, we optimize various DECIGO parameters by maximizing the signal-to-noise
ratio (SNR), for the primordial GWs to quantum noise including the effects of
diffraction loss. We evaluated the power spectrum density for one cluster in
DECIGO utilizing the quantum noise of one differential Fabry-Perot
interferometer. Then we calculated the SNR by correlating two clusters in the
same position. We performed the optimization for two cases: the constant
mirror-thickness case and the constant mirror-mass case. As a result, we
obtained the SNR dependence on the mirror radius, which also determines various
DECIGO parameters. This result is the first step toward optimizing the DECIGO
design by considering the practical constraints on the mirror dimension and
implementing other noise sources.Comment: 13 pages, 12 figure
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