TeV scale mirage mediation in NMSSM

We study the next-to-minimal supersymmetric standard model. We consider soft supersymmetry breaking parameters, which are induced by the mirage mediation mechanism of supersymmetry breaking. We concentrate on the mirage mediation, where the so-called mirage scale is the TeV scale. In this scenario, we can realize the up-type Higgs soft mass of O(200) GeV, while other masses such as gaugino masses and stop masses are heavy such as 1 TeV or more. Cancellation between the effective \mu-term and the down-type Higgs soft mass ameliorates the fine-tuning in the electroweak symmetry breaking even for \mu=O(500) GeV. The mixing between the doublet and singlet Higgs bosons is suppressed by (\lambda/\kappa)/tan\beta. Then the lightest doublet Higgs mass naturally reaches 125 GeV lifted by the new quartic coupling. The higgsino and singlino are light and their linear combination is the lightest superparticle.Comment: 24 pages, 24 figures, Numerical analysis is replaced with the version calculated by NMSSMTools. Comments and references are added on the suppressed doublet-singlet mixing and cases in which the 125 GeV boson is the 2nd lightest CP-even scalar. The version accepted by JHE

Topological quantization and degeneracy in Josephson-junction arrays

We consider the conductivity quantization in two-dimensional arrays of mesoscopic Josephson junctions, and examine the associated degeneracy in various regimes of the system. The filling factor of the system may be controlled by the gate voltage as well as the magnetic field, and its appropriate values for quantization is obtained by employing the Jain hierarchy scheme both in the charge description and in the vortex description. The duality between the two descriptions then suggests the possibility that the system undergoes a change in degeneracy while the quantized conductivity remains fixed.Comment: To appear in Phys. Rev.

Inflation with blowing-up solution of cosmological constant problem

The cosmological constant problem is how one chooses, without fine-tuning, one singular point $\Lambda_{eff}=0$ for the 4D cosmological constant. We argue that some recently discovered {\it weak self-tuning} solutions can be viewed as blowing-up this one point into a band of some parameter. These weak self-tuning solutions may have a virtue that only de Sitter space solutions are allowed outside this band, allowing an inflationary period. We adopt the hybrid inflation at the brane to exit from this inflationary phase and to enter into the standard Big Bang cosmology.Comment: LaTeX file of 20 pages including 2 eps figure

Shot Noise and Full Counting Statistics from Non-equilibrium Plasmons in Luttinger-Liquid Junctions

We consider a quantum wire double junction system with each wire segment described by a spinless Luttinger model, and study theoretically shot noise in this system in the sequential tunneling regime. We find that the non-equilibrium plasmonic excitations in the central wire segment give rise to qualitatively different behavior compared to the case with equilibrium plasmons. In particular, shot noise is greatly enhanced by them, and exceeds the Poisson limit. We show that the enhancement can be explained by the emergence of several current-carrying processes, and that the effect disappears if the channels effectively collapse to one due to, {\em e.g.}, fast plasmon relaxation processes.Comment: 9 pages; IOP Journal style; several changes in the tex

Magnetic Excitations and Continuum of a Field-Induced Quantum Spin Liquid in α\alpha-RuCl3_3

We report on terahertz spectroscopy of quantum spin dynamics in $\alpha$-RuCl$_3$, a system proximate to the Kitaev honeycomb model, as a function of temperature and magnetic field. An extended magnetic continuum develops below the structural phase transition at $T_{s2}=62$K. With the onset of a long-range magnetic order at $T_N=6.5$K, spectral weight is transferred to a well-defined magnetic excitation at $\hbar \omega_1 = 2.48$meV, which is accompanied by a higher-energy band at $\hbar \omega_2 = 6.48$meV. Both excitations soften in magnetic field, signaling a quantum phase transition at $B_c=7$T where we find a broad continuum dominating the dynamical response. Above $B_c$, the long-range order is suppressed, and on top of the continuum, various emergent magnetic excitations evolve. These excitations follow clear selection rules and exhibit distinct field dependencies, characterizing the dynamical properties of the field-induced quantum spin liquid

Reconstruction of Fundamental SUSY Parameters

We summarize methods and expected accuracies in determining the basic low-energy SUSY parameters from experiments at future e$^+$e$^-$ linear colliders in the TeV energy range, combined with results from LHC. In a second step we demonstrate how, based on this set of parameters, the fundamental supersymmetric theory can be reconstructed at high scales near the grand unification or Planck scale. These analyses have been carried out for minimal supergravity [confronted with GMSB for comparison], and for a string effective theory.Comment: 8 pages, latex, 7 figures, expanded version of contributions to the proceedings of ICHEP.2002 (Amstersdam) and LCWS.2002 (Jeju Island

Size effect on magnetism of Fe thin films in Fe/Ir superlattices

In ferromagnetic thin films, the Curie temperature variation with the thickness is always considered as continuous when the thickness is varied from $n$ to $n+1$ atomic planes. We show that it is not the case for Fe in Fe/Ir superlattices. For an integer number of atomic planes, a unique magnetic transition is observed by susceptibility measurements, whereas two magnetic transitions are observed for fractional numbers of planes. This behavior is attributed to successive transitions of areas with $n$ and $n+1$ atomic planes, for which the $T_c$'s are not the same. Indeed, the magnetic correlation length is presumably shorter than the average size of the terraces. Monte carlo simulations are performed to support this explanation.Comment: LaTeX file with Revtex, 5 pages, 5 eps figures, to appear in Phys. Rev. Let

Singlet superfield extension of the minimal supersymmetric standard model with Peccei-Quinn symmetry and a light pseudoscalar Higgs boson at the LHC

Motivated by the mu-problem and the axion solution to the strong CP-problem, we extend the MSSM with one more chiral singlet field $X_e$. The underlying PQ-symmetry allows only one more term $X_e H_u H_d$ in the superpotential. The spectrum of the Higgs system includes a light pseudoscalar $a_X$ (in addition to the standard CP-even Higgs boson), predominantly decaying to two photons: $a_X \to \gamma \gamma$. Both Higgs bosons might be in the range accessible to current LHC experiments.Comment: 5 pages with 3 figure