934 research outputs found
Diabetic pancreatic β cells ARNT all they should be
A complex network of interacting transcription factors plays a critical role in normal pancreatic β cell function, with mutations in certain transcription factor genes known to cause diabetes. In a recent issue of Cell, Gunton et al. (2005) demonstrate a role for the transcription factor ARNT/HIF1β (hydrocarbon nuclear receptor translocator/hypoxia-inducible factor 1 β) in normal β cell function. ARNT expression is reduced in diabetic human islets and β cell-specific ARNT knockout mice show the impaired glucose tolerance and abnormal insulin secretion that are characteristic of type 2 diabetes
Precision Measurements at The Higgs Resonance: A Probe of Radiative Fermion Masses
The possibility of radiative generation of fermion masses from soft
supersymmetry breaking chiral flavor violation is explored. Consistent models
are identified and classified. Phenomenological implications for electric
dipole moments and magnetic moments, as well as collider probes -- in
particular those relevant at the Higgs resonance -- are discussed. It is shown
that partial widths are enhanced compared with the
minimal supersymmetric standard model.Comment: 7 pages, 1 figure, aipproc.sty (included). Talk presented by N.
Polonsky at the Workshop on Physics at the First Muon Collider and the Front
End of a Muon Collider, Fermilab, November 6-9, 199
Effects of supersymmetric grand unification scale physics on
Although calculations of the rate in supersymmetric
grand unified models have always either ignored the gluino mediated
contribution or found it to be negligible, we show that taking universal
supersymmetry breaking masses at the Planck scale, rather than at the gauge
unification scale as is customary, leads to the gluino contribution being more
significant and in fact sometimes even larger than the chargino mediated
contributions when and is of order 1. The impact is
greatest felt when the gluinos are relatively light. Taking the universal
boundary condition at the Planck scale also has an effect on the chargino
contribution by increasing the effect of the wino and higgsino-wino mediated
decays. The neutralino mediated contribution is found to be enhanced, but
nevertheless it remains relatively insignificant.Comment: Title changed, final version as accepted for PRD, 12 pages, 6 Figures
(Figs.2-6 included, uuencoded, epsf.tex
The strong coupling, unification, and recent data
The prediction of the strong coupling assuming (supersymmetric) coupling
constant unification is reexamined. We find, using the new electroweak data,
. The implications of the large
value are discussed. The role played by the beauty width is
stressed. It is also emphasized that high-energy (but not low-energy)
corrections could significantly diminish the prediction. However, unless
higher-dimension operators are assumed to be suppressed, at present one cannot
place strong constraints on the super-heavy spectrum. Non-leading electroweak
threshold corrections are also discussed.Comment: 12 pages, LaTex + RevTex, uuencoded postscript file (including 13
figures) is attached. Also available at ftp://dept.physics.upenn.edu/pub/Ni
Single flux quantum circuits with damping based on dissipative transmission lines
We propose and demonstrate the functioning of a special Rapid Single Flux
Quantum (RSFQ) circuit with frequency-dependent damping. This damping is
achieved by shunting individual Josephson junctions by pieces of open-ended RC
transmission lines. Our circuit includes a toggle flip-flop cell, Josephson
transmission lines transferring single flux quantum pulses to and from this
cell, as well as DC/SFQ and SFQ/DC converters. Due to the desired
frequency-dispersion in the RC line shunts which ensures sufficiently low noise
at low frequencies, such circuits are well-suited for integrating with the
flux/phase Josephson qubit and enable its efficient control.Comment: 6 pages incl. 6 figure
The Superpartner Spectrum of Gaugino Mediation
We compute the superpartner masses in a class of models with gaugino
mediation (or no-scale) boundary conditions at a scale between the GUT and
Planck scales. These models are compelling because they are simple, solve the
supersymmetric flavor and CP problems, satisfy all constraints from colliders
and cosmology, and predict the superpartner masses in terms of very few
parameters. Our analysis includes the renormalization group evolution of the
soft-breaking terms above the GUT scale. We show that the running above the GUT
scale is largely model independent and find that a phenomenologically viable
spectrum is obtained.Comment: 15 page
-term as the origin of baryon and lepton number asymmetry
We study a possibility of combining an origin of the -term and the
baryon and lepton number asymmetry. If we assume that the -term is
generated through a flat direction of a singlet scalar field, the coherent
oscillation of this condensate around its potential minimum can store the
global U(1) charge asymmetry. The decay of this condensate can distribute this
asymmetry into the lepton and baryon number asymmetry as far as its decay
occurs at an appropriate temperature. We examine the compatibility between this
scenario and the small neutrino mass generation based on both the ordinary
seesaw mechanism and the bilinear R-parity violating terms.Comment: 22 pages, published versio
- …