8,135 research outputs found
Focus Point Gauge Mediation with Incomplete Adjoint Messengers and Gauge Coupling Unification
As the mass limits on supersymmetric particles are gradually pushed to higher
values due to their continuing non-observation at the CERN LHC, looking for
focus point regions in the supersymmetric parameter space, which shows
considerably reduced fine-tuning, is increasingly more important than ever. We
explore this in the context of gauge mediated supersymmetry breaking with
messengers transforming in the adjoint representation of the gauge group,
namely, octet of color SU(3) and triplet of weak SU(2). A distinctive feature
of this scenario is that the focus point is achieved by fixing a single
combination of parameters in the messenger sector, which is invariant under the
renormalization group evolution. Because of this invariance, the focus point
behavior is well under control once the relevant parameters are fixed by a more
fundamental theory. The observed Higgs boson mass is explained with a
relatively mild fine-tuning 60-150. Interestingly, even in the
presence of incomplete messenger multiplets of the SU(5) GUT group, the gauge
couplings still unify perfectly, but at a scale which is one or two orders of
magnitude above the conventional GUT scale. Because of this larger unification
scale, the colored Higgs multiplets become too heavy to trigger proton decay at
a rate larger than the experimentally allowed limit.Comment: 9 pages, 4 figures, the version to be publishe
Quantum Logic Processor: A Mach Zehnder Interferometer based Approach
Quantum Logic Processors can be implemented with Mach Zehnder
Interferometer(MZI) configurations for the Quantum logic operations and gates.
In this paper, its implementation for both optical and electronic system has
been presented. The correspondence between Jones matrices for photon
polarizations and Pauli spin matrices for electrons gives a representation of
all the unitary matrices for the quantum gate operations. A novel quantum
computation system based on a Electronic Mach Zehnder Interferometer(MZI) has
also been proposed. It uses the electron spin as the primary qubit. Rashba
effect is used to create Unitary transforms on spin qubits. A mesoscopic Stern
Gerlach apparatus can be used for both spin injection and detection. An
intertwined nanowire design is used for the MZI. The system can implement all
single and double qubit gates. It can easily be coupled to form an array. Thus
the Quantum Logic Processor (QLP) can be built using the system as its
prototype.Comment: 19 pages, 6 figures, 8 Table
Density functional theory for fermions close to the unitary regime
We consider interacting Fermi systems close to the unitary regime and compute
the corrections to the energy density that are due to a large scattering length
and a small effective range. Our approach exploits the universality of the
density functional and determines the corrections from the analyical results
for the harmonically trapped two-body system. The corrections due to the finite
scattering length compare well with the result of Monte Carlo simulations. We
also apply our results to symmetric neutron matter.Comment: 4 pages, 2 figure
Energy dependent wavelength of the ion induced nanoscale ripple
Wavelength variation of ion beam induced nanoscale ripple structure has
received much attention recently due to its possible application in
nanotechnology. We present here results of Ar bombarded Si in the energy
range 50 to 140 keV to demonstrate that with beam scanning the ripple
wavelength increases with ion energy and decreases with energy for irradiation
without ion beam scanning. An expression for the energy dependence of ripple
wavelength is proposed taking into simultaneous effect of thermally activated
surface diffusion and ion induced effective surface diffusion.Comment: REVTeX (4 pages), 3 EPS figure
A natural scenario for heavy colored and light uncolored superpartners
Influenced by the current trend of experimental data, especially from the
LHC, we construct a supersymmetric scenario where a natural dynamics makes the
squarks and gluino super-heavy (order 10 TeV) while keeping the sleptons and
the weak gauginos light (100-500 GeV). The dynamics relies on the interfusion
of two underlying ideas: () gauge mediation of supersymmetry breaking with
two messenger multiplets, one transforming as a triplet of weak SU(2) and the
other as an octet of color SU(3); () perturbative gauge coupling
unification at the string scale even with these incomplete SU(5) multiplets.
Interestingly, the relative magnitude of the triplet and octet messenger scales
that ensures gauge unification at the two-loop level also helps to naturally
keep the uncolored superpartners light while making the colored ones heavy.Comment: v2: Clarifying remarks added in page 5, results and conclusions
unchanged, version to appear in Physics Letters
A practical GMSB model for explaining the muon (g-2) with gauge coupling unification
We present a gauge mediated supersymmetry breaking model having weak SU(2)
triplet, color SU(3) octet and SU(5) 5-plet messengers, that can simultaneously
explain the muon data within 1 and the observed Higgs boson
mass of 125 GeV. Gauge coupling unification is nontrivially maintained. Most of
the parameter space satisfying both is accessible to the 14 TeV LHC. The
lighter of the two staus weighs around (100-200) GeV, which can be a potential
target of the ILC.Comment: 6 pages, 5 eps figure
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