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Preliminary results of steel containment vessel model test
A high pressure test of a mixed-scaled model (1:10 in geometry and 1:4 in shell thickness) of a steel containment vessel (SCV), representing an improved boiling water reactor (BWR) Mark II containment, was conducted on December 11-12, 1996 at Sandia National Laboratories. This paper describes the preliminary results of the high pressure test. In addition, the preliminary post-test measurement data and the preliminary comparison of test data with pretest analysis predictions are also presented
EVM and Achievable Data Rate Analysis of Clipped OFDM Signals in Visible Light Communication
Orthogonal frequency division multiplexing (OFDM) has been considered for
visible light communication (VLC) thanks to its ability to boost data rates as
well as its robustness against frequency-selective fading channels. A major
disadvantage of OFDM is the large dynamic range of its time-domain waveforms,
making OFDM vulnerable to nonlinearity of light emitting diodes (LEDs). DC
biased optical OFDM (DCO-OFDM) and asymmetrically clipped optical OFDM
(ACO-OFDM) are two popular OFDM techniques developed for the VLC. In this
paper, we will analyze the performance of the DCO-OFDM and ACO-OFDM signals in
terms of error vector magnitude (EVM), signal-to-distortion ratio (SDR), and
achievable data rates under both average optical power and dynamic optical
power constraints. EVM is a commonly used metric to characterize distortions.
We will describe an approach to numerically calculate the EVM for DCO-OFDM and
ACO-OFDM. We will derive the optimum biasing ratio in the sense of minimizing
EVM for DCO-OFDM. Additionally, we will formulate the EVM minimization problem
as a convex linear optimization problem and obtain an EVM lower bound against
which to compare the DCO-OFDM and ACO-OFDM techniques. We will prove that the
ACO-OFDM can achieve the lower bound. Average optical power and dynamic optical
power are two main constraints in VLC. We will derive the achievable data rates
under these two constraints for both additive white Gaussian noise (AWGN)
channel and frequency-selective channel. We will compare the performance of
DCO-OFDM and ACO-OFDM under different power constraint scenarios
Enhancement of Radiatively Induced Magnetic Moment Form-Factors of Muon: an Effective Lagrangian Approach
Using an effective lagrangian approach, we identify a class of models in
which the loop-induced magnetic moment form-factors of muon are enhanced by
possibly large factors
(\Lambda^2_F/\Lambda^2)(m_\tau/m_\mu)\ln(m_\tau^2/\Lambda^2) or
(\Lambda^2_F/\Lambda^2)\ln(m_\mu^2/\Lambda^2), where \Lambda is the scale of
new physics and \Lambda_F is the Fermi scale. These follow from left- and
right-chirality mixing dimension-8 operators which for relatively small
\Lambda, as required to explain the new (g_\mu-2) measurement, dominate over
dimension-6 operators. Thus significant enhancement of new physics
contributions to (g_\mu-2) and, in the presence of intergenerational couplings,
also to the \mu\to e\gamma decay rate is possible. We discuss the compatibility
of the (g_\mu-2) and \mu\to e\gamma experimental data in this case and comment
on the enhancement of the electron anomalous magnetic moment. An explicit model
is presented to illustrate the general results.Comment: Discussion on the enhancement of electron anomalous magnetic moment
included. New references adde
Bottom-Tau Unification in SUSY SU(5) GUT and Constraints from b to s gamma and Muon g-2
An analysis is made on bottom-tau Yukawa unification in supersymmetric (SUSY)
SU(5) grand unified theory (GUT) in the framework of minimal supergravity, in
which the parameter space is restricted by some experimental constraints
including Br(b to s gamma) and muon g-2. The bottom-tau unification can be
accommodated to the measured branching ratio Br(b to s gamma) if superparticle
masses are relatively heavy and higgsino mass parameter \mu is negative. On the
other hand, if we take the latest muon g-2 data to require positive SUSY
contributions, then wrong-sign threshold corrections at SUSY scale upset the
Yukawa unification with more than 20 percent discrepancy. It has to be
compensated by superheavy threshold corrections around the GUT scale, which
constrains models of flavor in SUSY GUT. A pattern of the superparticle masses
preferred by the three requirements is also commented.Comment: 21pages, 6figure
Implications of the Muon Anomalous Magnetic Moment for Supersymmetry
We re-examine the bounds on supersymmetric particle masses in light of the
E821 data on the muon anomalous magnetic moment. We confirm, extend and
supersede previous bounds. In particular we find (at one sigma) no lower limit
on tan(beta) or upper limit on the chargino mass implied by the data at
present, but at least 4 sparticles must be lighter than 700 to 820 GeV and at
least one sparticle must be lighter than 345 to 440 GeV. However, the E821
central value bounds tan(beta) > 4.7 and the lighter chargino mass by 690 GeV.
For tan(beta) < 10, the data indicates a high probability for direct discovery
of SUSY at Run II or III of the Tevatron.Comment: 20 pages LaTeX, 14 figures; references adde
Charged-Lepton-Flavour Violation in the CMSSM in View of the Muon Anomalous Magnetic Moment
We use the BNL E821 measurement of g - 2, the anomalous magnetic moment of
the muon, to normalize, within a supersymmetric GUT framework, constrained MSSM
(CMSSM) predictions for processes that violate charged-lepton flavour
conservation, including mu to e gamma, mu to e conversion and K^0_L to mu e. We
illustrate our analysis with two examples of lepton mass matrix textures
motivated by data on neutrino oscillations. We find that mu to e gamma may well
occur at a rate within one or two (two or three) orders of magnitude of the
present experimental upper limit if g - 2 is within the one- (two-)standard
deviation range indicated by E821. We also find that mu to e conversion is
likely to occur at rate measurable by MECO, and there is a chance that K^0_L to
mu e may be observable in an experiment using an intense proton source.Comment: 14 pages, 3 eps figure
Supersymmetric Relations Among Electromagnetic Dipole Operators
Supersymmetric contributions to all leptonic electromagnetic dipole operators
have essentially identical diagramatic structure. With approximate slepton
universality this allows the muon anomalous magnetic moment to be related to
the electron electric dipole moment in terms of supersymmetric phases, and to
radiative flavor changing lepton decays in terms of small violations of slepton
universality. If the current discrepancy between the measured and Standard
Model values of the muon anomalous magnetic moment is due to supersymmetry, the
current bound on the electron electric dipole moment then implies that the
phase of the electric dipole operator is less than . Likewise
the current bound on decay implies that the fractional
selectron-smuon mixing in the left-left mass squared matrix, \delta m_{\smuon
\selectron}^2 / m_{\slepton}^2, is less than . These relations and
constraints are fairly insensitive to details of the superpartner spectrum for
moderate to large .Comment: Latex, 38 pages, 2 figure
Topcolor assisted technicolor models and muon anomalous magnetic moment
We discuss and estimate the contributions of the new particles predicted by
topcolor assisted technicolor(TC2) models to the muon anomalous magnetic moment
. Our results show that the contributions of Pseudo Goldstone bosons
are very small which can be safely ignored. The main contributions come from
the ETC gauge boson and topcolor gauge boson . If we
demand that the mass of is consistent with other experimental
constrains, its contributions are smaller than that of . With
reasonable values of the parameters in TC2 models, the observed BNL results for
could be explained.Comment: latex file, 11 pages, several figures and references adde
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