2,088 research outputs found
Democratic mass matrices induced by strong gauge dynamics and large mixing angles for leptons
We consider dynamical realization of the democratic type Yukawa coupling
matrices as the Pendelton-Ross infrared fixed points.?Such fixed points of the
Yukawa couplings become possible by introducing many Higgs fields, which are
made superheavy but one massless mode. Explicitly, we consider a strongly
coupled GUT based on , where rapid convergence to the
infrared fixed point generates sufficiently large mass hierarchy for quarks and
leptons. Especially, it is found that the remarkable difference between mixing
angles in the quark and lepton sectors may be explained as a simple dynamical
consequence. We also discuss a possible scenario leading to the realistic mass
spectra and mixing angles for quarks and leptons. In this scheme, the Yukawa
couplings not only for top but also for bottom appear close to their
quasi-fixed points at low energy and, therefore, should be large.Comment: 25 pages, 5 figure
Yukawa Hierarchy Transfer from Superconformal Sector and Degenerate Sfermion Masses
We propose a new type of supersymmetric models coupled to superconformal
field theories (SCFT's), leading simultaneously to hierarchical Yukawa
couplings and completely degenerate sfermion masses. We consider models with an
extra Abelian gauge symmetry to generate hierarchical structure for couplings
between the SM sector and the SC sector. Interestingly, this hierarchy is
inversely transferred to the Yukawa couplings in the SM sector. In this type of
models, flavor-independent structure of the superconformal fixed point
guarantees that the sfermion masses of the first and the second generations are
completely degenerate at low energy.Comment: 11 pages, latex, 3 figure
Non-perturbative Kahler Potential, Dilaton Stabilization and Fayet-Iliopoulos Term
We study the dilaton stabilization in models with anomalous U(1) symmetry by
adding specific string-motivated, non-perturbative corrections to the
tree-level dilaton K\"{a}hler potential. We find that the non-perturbative
effects can stabilize the dilaton at a desirably large value. We also observe
that the size of Fayet-Iliopoulos term is reduced at the stabilized point.Comment: 10 pages, 2 figure
Large Mass Scale by Strong Gauge Dynamics with Infrared Fixed Point
We consider a mechanism for realizing the desired decoupling of
strongly-coupled sector which is supposed to generate hierarchical structure of
the Yukawa couplings. In our mechanism, the same strongly-coupled sector is
responsible for generating a sufficiently flat potential and a large vacuum
expectation value (VEV) of a gauge-singlet scalar field by suppressing its soft
scalar mass and self-coupling. Vacuum instability is caused by
supersymmetry-breaking A-term of order 10 TeV. We explicitly demonstrate the
infrared convergence of soft scalar masses due to strongly-coupled dynamics and
show the soft mass of the singlet is at most comparable to soft masses of
squarks and sleptons, which are much suppressed than the A-term. The physical
mass scale of the decoupling is calculated in a self-consistent way. We also
reinterpret the result in terms of a RG-improved effective potential.Comment: 18 pages, 4 figures, 1 table, LaTeX (PTPTeX style
On the Scope Interaction of Japanese Indefinites: An Epsilon Calculus Approach
PACLIC 23 / City University of Hong Kong / 3-5 December 200
Induced top Yukawa coupling and suppressed Higgs mass parameters
In the scenarios with heavy top squarks, mass parameters of the Higgs field
must be fine-tuned due to a large logarithmic correction to the soft scalar
mass. We consider a new possibility that the top Yukawa coupling is small above
TeV scale. The large top mass is induced from strong Yukawa interaction of the
Higgs with another gauge sector, in which supersymmetry breaking parameters are
given to be small. Then it is found that the logarithmic correction to the
Higgs soft scalar mass is suppressed in spite of the strong coupling and the
fine-tuning is ameliorated. We propose an explicit model coupled to a
superconformal gauge theory which realizes the above situation.Comment: RevTeX4 style, 10 pages, 3 figure
DOES SIDE OF AMPUTATION AFFECT 200- AND 400-M RACE TIME IN SPRINTERS USING RUNNING-SPECIFIC PROSTHESES?
Current Paralympic guidelines for track events are generally based on level of amputation, not side of amputation. Since 200- and 400-m sprint races are performed in a counter clockwise direction, the effects of amputations side on sprint race performance in athletes with unilateral lower limb amputation should be investigated. Forty-five unilateral transtibial amputees participating in elite-level 200- and 400-m races were analysed from publicly available Internet broadcasts. For each athlete, official race time, and amputation side were determined. We found no significant difference in official race time between left and right side amputees during the 200- and 400-m sprint, indicating that sprint performance on a standard track in amputee athletes is not affected by amputation side
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