15,902 research outputs found
Toward an understanding of short distance repulsions among baryons in QCD -- NBS wave functions and operator product expansion --
We report on our recent attempts to determine the short distance behaviors of
general 2-baryon and 3-baryon forces, which are defined from the
Nambu-Bethe-Salpeter(NBS) wave function, by using the operator product
expansion and a renormalization group analysis in QCD. We have found that the
repulsion at short distance increases as the number of valence quarks increases
or when the number of different flavors involved decreases. This global
tendency suggests a Pauli suppression principle among quark fields at work.Comment: 14 pages, add two exmples in sect.3.4, a version accepted for
Progress of Theoretical Physic
Flows to Schrodinger Geometries
We construct RG flow solutions interpolating AdS and Schrodinger geometries
in Abelian Higgs models obtained from consistent reductions of type IIB
supergravity and M-theory. We find that z=2 Schrodinger geometries can be
realized at the minima of scalar potentials of these models, where a scalar
charged under U(1) gauge symmetry obtains a nonzero vacuum expectation value.
The RG flows are induced by an operator deformation of the dual CFT. The flows
are captured by fake superpotentials of the theories.Comment: 19 pages, 5 figures, v2: typos corrected, references added, published
version in PR
Momentum-resolved charge excitations in high-Tc cuprates studied by resonant inelastic x-ray scattering
We report a Cu K-edge resonant inelastic x-ray scattering (RIXS) study of
high-Tc cuprates. Momentum-resolved charge excitations in the CuO2 plane are
examined from parent Mott insulators to carrier-doped superconductors. The Mott
gap excitation in undoped insulators is found to commonly show a larger
dispersion along the [pi,pi] direction than the [pi,0] direction. On the other
hand, the resonance condition displays material dependence. Upon hole doping,
the dispersion of the Mott gap excitation becomes weaker and an intraband
excitation appears as a continuum intensity below the gap at the same time. In
the case of electron doping, the Mott gap excitation is prominent at the zone
center and a dispersive intraband excitation is observed at finite momentum
transfer
Macroeconomic Interdependence of Japan and the United States: Some Simulation Results
In this paper we examine the macroeconomic interdependence of Japan and the U.S. using a medium-scale simulation model of the world economy. Our goal is to determine how shifts in macroeconomic policies in the U.S. or Japan affectthe other country as well as the rest of the world. In particular we examine the following three issues: (1) the likely macroeconomic ramifications for the U.S., Europe and Japan of significant budget cuts in the U.S.; (2) the macroeconomic implications of a protectionist tariff imposed by the U.S.; and (3) the scope for policy coordination among the U.S., Japan and Europe.
Flat-band excitonic states in Kagome lattice on semiconductor surface
Excitonic properties in the Kagome lattice system, which is produced by
quantum wires on semiconductor surfaces, are investigated by using the exact
diagonalization of a tight binding model. It is shown that due to the existence
of flat bands the binding energy of exciton becomes remarkably large in the
two-dimensional Kagome lattice compared to that in one-dimensional lattice, and
the exciton Bohr radius is quite small as large as a lattice constant. We also
discuss the magnetic field effects on the exciton binding energy and the
stability of exciton against the creation of charged exciton and biexciton.Comment: 5 pages, 5 figure
Mixings of 4-quark components in light non-singlet scalar mesons in QCD sum rules
Mixings of 4-quark components in the non-singlet scalar mesons are studied in
the QCD sum rules. We propose a formulation to evaluate the cross correlators
of q\bar q and qq\bar q \bar q operators and to define the mixings of different
Fock states in the sum rule. It is applied to the non-singlet scalar mesons,
a_0 and K_0^\ast. It is found that the 4-quark operators predict lower masses
than the q\bar q operators and that the 4-quark states occupy about 70-90% of
the lowest mass states.Comment: 8 pages, 9 figure
Moment inequalities and their application
This paper provides conditions under which the inequality constraints generated by either single agent optimizing behavior, or by the Nash equilibria of multiple agent problems, can be used as a basis for estimation and inference. We also add to the econometric literature on inference in models defined by inequality constraints by providing a new specification test and methods of inference for the boundaries of the model's identified set. Two applications illustrate how the use of inequality constraints can simplify the problem of obtaining estimators from complex behavioral models of substantial applied interest.
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