2,050 research outputs found
Geometrical Construction of Heterogeneous Loop Amplitudes in 2D Gravity
We study a disk amplitude which has a complicated heterogeneous matter
configuration on the boundary in a system of the (3,4) conformal matter coupled
to two-dimensional gravity. It is analyzed using the two-matrix chain model in
the large N limit. We show that the disk amplitude calculated by
Schwinger-Dyson equations can completely be reproduced through purely
geometrical consideration. From this result, we speculate that all
heterogeneous loop amplitudes can be derived from the geometrical consideration
and the consistency among relevant amplitudes.Comment: 13 pages, 11 figure
Pure Gravity Mediation with m_{3/2} = 10-100TeV
Recently, the ATLAS and CMS collaborations reported exciting hints of a
Standard Model-like Higgs boson with a mass around 125GeV. Such a Higgs boson
mass can be easily obtained in the minimal supersymmetric Standard Model based
on the "pure gravity mediation model" where the sfermion masses and the Higgs
mass parameters are in tens to hundreds TeV range while the gauginos are in the
hundreds GeV to TeV range. In this paper, we discuss detalis of the gaugino
mass spectrum in the pure gravity mediation model. We also discuss the signals
of the model at the current and future experiments such as cosmic ray
observations and the LHC experiments. In particular, we show that the parameter
space which is consistent with the thermal leptogenesis can be fully surveyed
experimentally in the foreseeable future.Comment: 21 pages, 7 figure
P-Wave Charmed-Strange Mesons
We examine charmed-strange mesons within the framework of the constituent
quark model, focusing on the states with L=1. We are particularly interested in
the mixing of two spin-states that are involved in and the
recently discovered . We assume that these two mesons form a pair
of states with J=1. These spin-states are mixed by a type of the spin-orbit
interaction that violates the total-spin conservation. Without assuming
explicit forms for the interactions as functions of the interquark distance, we
relate the matrix elements of all relevant spin-dependent interactions to the
mixing angle and the observed masses of the L=1 quartet. We find that the
spin-spin interaction, among various types of the spin-dependent interactions,
plays a particularly interesting role in determining the spin structure of
and
Electro-spinon in one-dimensional Mott insulator
The low-energy dynamical optical response of dimerized and undimerized spin
liquid states in a one-dimensional charge transfer Mott insulator is
theoretically studied. An exact analysis is given for the low-energy asymptotic
behavior using conformal field theory for the undimerized state. In the
dimerized state, the infrared absorption due to the bound state of two
solitons, i.e, the breather mode, is predicted with an accurate estimate for
its oscillator strength, offering a way to detect experimentally the excited
singlet state. Effects of external magnetic fields are also discussed.Comment: 5 pages, 2 figures, some typos are correcte
Observability inequalities for transport equations through Carleman estimates
We consider the transport equation \ppp_t u(x,t) + H(t)\cdot \nabla u(x,t) =
0 in \OOO\times(0,T), where and \OOO\subset \R^d is a bounded
domain with smooth boundary \ppp\OOO. First, we prove a Carleman estimate for
solutions of finite energy with piecewise continuous weight functions. Then,
under a further condition which guarantees that the orbits of intersect
\ppp\OOO, we prove an energy estimate which in turn yields an observability
inequality. Our results are motivated by applications to inverse problems.Comment: 18 pages, 3 figure
Bottom-Up Approach to Moduli Dynamics in Heavy Gravitino Scenario : Superpotential, Soft Terms and Sparticle Mass Spectrum
The physics of moduli fields is examined in the scenario where the gravitino
is relatively heavy with mass of order 10 TeV, which is favored in view of the
severe gravitino problem. The form of the moduli superpotential is shown to be
determined, if one imposes a phenomenological requirement that no physical CP
phase arise in gaugino masses from conformal anomaly mediation. This bottom-up
approach allows only two types of superpotential, each of which can have its
origins in a fundamental underlying theory such as superstring. One
superpotential is the sum of an exponential and a constant, which is identical
to that obtained by Kachru et al (KKLT), and the other is the racetrack
superpotential with two exponentials. The general form of soft supersymmetry
breaking masses is derived, and the pattern of the superparticle mass spectrum
in the minimal supersymmetric standard model is discussed with the KKLT-type
superpotential. It is shown that the moduli mediation and the anomaly mediation
make comparable contributions to the soft masses. At the weak scale, the
gaugino masses are rather degenerate compared to the minimal supergravity,
which bring characteristic features on the superparticle masses. In particular,
the lightest neutralino, which often constitutes the lightest superparticle and
thus a dark matter candidate, is a considerable admixture of gauginos and
higgsinos. We also find a small mass hierarchy among the moduli, gravitino, and
superpartners of the standard-model fields. Cosmological implications of the
scenario are briefly described.Comment: 45 pages, 10 figures, typos correcte
Implication of Omega_m through the Morphological Analysis of Weak Lensing Fields
We apply the morphological descriptions of two-dimensional contour map, the
so-called Minkowski functionals (the area fraction, circumference, and Euler
characteristics), to the convergence field of the
large-scale structure reconstructed from the shear map produced by the
ray-tracing simulations. The perturbation theory of structure formation has
suggested that the non-Gaussian features on the Minkowski functionals with
respect to the threshold in the weakly nonlinear regime are induced by the
three skewness parameters of that are sensitive to the density
parameter of matter, . We show that, in the absence of noise
due to the intrinsic ellipticities of source galaxies with which the
perturbation theory results can be recovered, the accuracy of
determination is improved by using the Minkowski functionals
compared to the conventional method of using the direct measure of skewness.Comment: 4 pages, 3 figures, to appear in ApJ Lette
Field and temperature dependence of the NMR relaxation rate in the magnetic quadrupolar liquid phase of spin-1/2 frustrated ferromagnetic chains
It is generally difficult to experimentally distinguish magnetic multipolar
orders in spin systems. Recently, it was proposed that the temperature
dependence of the nuclear magnetic resonance relaxation rate 1/T_1 can involve
an indirect, but clear signature of the field-induced spin nematic or
multipolar Tomonaga-Luttinger (TL) liquid phase [Phys. Rev. B79, 060406(R)
(2009)]. In this paper, we evaluate accurately the field and temperature
dependence of 1/T_1 in spin-1/2 frustrated J1-J2 chains combining
field-theoretical techniques with numerical data. Our results demonstrate that
isotherms of 1/T_1 as a function of magnetic field also exhibit distinctive
non-monotonic behavior in spin nematic TL liquid, in contrast with the standard
TL liquid in the spin-1/2 Heisenberg chain. The relevance of our results to
quasi one-dimensional edge-sharing cuprate magnets, such as LiCuVO4, is
discussed.Comment: 11 pages (2 column), 5 figures, published versio
The Gravitino-Overproduction Problem in Inflationary Universe
We show that the gravitino-overproduction problem is prevalent among
inflation models in supergravity. An inflaton field \phi generically acquires
(effective) non-vanishing auxiliary field G_\phi, if the K\"ahler potential is
non-minimal. The inflaton field then decays into a pair of the gravitinos. We
extensively study the cosmological constraints on G_\phi for a wide range of
the gravitino mass. For many inflation models we explicitly estimate G_\phi,
and show that the gravitino-overproduction problem severely constrains the
inflation models, unless such an interaction as K = \kappa/2 |\phi|^2 z^2 +
h.c. is suppressed (here z is the field responsible for the supersymmetry
breaking). We find that many of them are already excluded or on the verge of,
if \kappa \sim O(1).Comment: 34 pages, 7 figures. v2: minor correction
Scalable Spin Amplification with a Gain over a Hundred
We propose a scalable and practical implementation of spin amplification
which does not require individual addressing nor a specially tailored spin
network. We have demonstrated a gain of 140 in a solid-state nuclear spin
system of which the spin polarization has been increased to 0.12 using dynamic
nuclear polarization with photoexcited triplet electron spins. Spin
amplification scalable to a higher gain opens the door to the single spin
measurement for a readout of quantum computers as well as practical
applications of nuclear magnetic resonance (NMR) spectroscopy to infinitesimal
samples which have been concealed by thermal noise.Comment: 6 pages, 7 figure
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