19,088 research outputs found
Human Capital, Economic Growth, and Regional Inequality in China
We study the dispersion in rates of provincial economic- and TFP growth in China. Our results show that regional growth patterns can be understood as a function of several interrelated factors, which include investment in physical capital, human capital, and infrastructure capital; the infusion of new technology and its regional spread; and market reforms, with a major step forward occurring following Deng Xiaoping’s “South Trip” in 1992. We find that FDI had much larger effect on TFP growth before 1994 than after, and we attribute this to emergence of other channels of technology transfer when marketization accelerated. We find that human capital positively affects output per worker and productivity growth. In particular, in terms of its direct contribution to production, educated labor has a much higher marginal product. Moreover, we estimate a positive, direct effect of human capital on TFP growth. This direct effect is hypothesized to come from domestic innovation activities. The estimated spillover effect of human capital on TFP growth is positive and statistically significant, which is very robust to model specifications and estimation methods. The spillover effect appears to be much stronger before 1994. We conduct cost-benefit analysis and a policy “experiment,” in which we project the impact increases in human capital and infrastructure capital on regional inequality. We conclude that investing in human capital will be an effective policy to reduce regional gaps in China as well as an efficient means to promote economic growth.http://deepblue.lib.umich.edu/bitstream/2027.42/57237/1/wp857 .pd
Corrections to di-Higgs boson production with light stops and modified Higgs couplings
The Higgs pair production in gluon fusion is a sensitive probe of
beyond-Standard Model (BSM) phenomena and its detection is a major goal for the
LHC and higher energy hadron collider experiments. In this work we reanalyze
the possible modifications of the Higgs pair production cross section within
low energy supersymmetry models. We show that the supersymmetric contributions
to the Higgs pair production cross section are strongly correlated with the
ones of the single Higgs production in the gluon fusion channel. Motivated by
the analysis of ATLAS and CMS Higgs production data, we show that the scalar
superpartners' contributions may lead to significant modification of the
di-Higgs production rate and invariant mass distribution with respect to the SM
predictions. We also analyze the combined effects on the di-Higgs production
rate of a modification of the Higgs trilinear and top-quark Yukawa couplings in
the presence of light stops. In particular, we show that due to the destructive
interference of the triangle and box amplitude contributions to the di-Higgs
production cross section, even a small modification of the top-quark Yukawa
coupling can lead to a significant increase of the di-Higgs production rate.Comment: 33 pages, 13 figures v2: minor improvements, PRD versio
Thresholdless dressed-atom laser in a photonic band-gap material
We demonstrate the capability of complete thresholdless lasing operation
between dressed states of a two-level atom located inside a microscopic cavity
engineered in a photonic band-gap material. We distinguish between threshold
and thresholdless behaves by analyzing the Mandel's Q parameter for the cavity
field. We find that the threshold behave depends on whether the spontaneous
emission is or is not present on the lasing transition. In the presence of the
spontaneous emission, the mean photon number of the cavity field exhibits
threshold behavior indicating that the system may operate as an ordinary laser.
When the spontaneous emission is eliminated on the lasing transition, no
threshold is observed for all values of the pumping rate indicating the system
becomes a thresholdless laser. Moreover, we find that under a thresholdless
operation, the mean photon number can increase nonlinearly with the pumping
rate, and this process is accompanied by a sub-Poisson statistics of the field.
This suggests that the nonclassical statistics can be used to distinguish a
nonlinear operation of the dressed-atom laser.Comment: 6 pages 4 figure
Relative entropy of entanglement of a kind of two qubit entangled states
We in this paper strictly prove that some block diagonalizable two qubit
entangled state with six none zero elements reaches its quantum relative
entropy entanglement by the a separable state having the same matrix structure.
The entangled state comprises local filtering result state as a special case.Comment: 5 page
Low-energy Effective Theory for One-dimensional Lattice Bosons near Integer Filling
A low-energy effective theory for interacting bosons on a one-dimensional
lattice at and near integer fillings is proposed. It is found that two sets of
bosonic phase fields are necessary in order to explain the complete phase
diagram. Using the present effective theory, the nature of the quantum phase
transitions among various phases can be identified. Moreover, the general
condition for the appearance of the recently proposed Pfaffian-like state can
be realized from our effective action.Comment: 6 pages, 2 figures, 1 tabl
The thermal evolution of nuclear matter at zero temperature and definite baryon number density in chiral perturbation theory
The thermal properties of cold dense nuclear matter are investigated with
chiral perturbation theory.
The evolution curves for the baryon number density, baryon number
susceptibility, pressure and the equation of state are obtained.
The chiral condensate is calculated and our result shows that when the baryon
chemical potential goes beyond , the absolute value of the
quark condensate decreases rapidly, which indicates a tendency of chiral
restoration.Comment: 17 pages, 9 figures, revtex
Effects of Flavor-dependent Annihilation on the Mixing Angle of the Isoscalar Octet-Singlet and Schwinger's Nonet Mass Formula
By incorporating the flavor-dependent quark-antiquark annihilation amplitude
into the mass-squared matrix describing the mixing of the isoscalar states of a
meson nonet, the new version of Schwinger's nonet mass formula which holds with
a high accuracy for the , , , and
nonets is derived and the mixing angle of isoscalar octet-singlet for these
nonets is obtained. In particular, the mixing angle of isoscalar octet-singlet
for pseudoscalar nonet is determined to take the value of , which
is in agreement with the value of deduced from a
rather exhaustive and up-to-date analysis of data. It is also pointed out that
the omission of the flavor-dependent annihilation effect might be a
factor resulting in the invalidity of Schwinger's original nonet mass formula
for pseudoscalar nonet.Comment: Latex, 7 page
Controlled polarization rotation of an optical field in multi-Zeeman-sublevel atoms
We investigate, both theoretically and experimentally, the phenomenon of
polarization rotation of a weak, linearly-polarized optical (probe) field in an
atomic system with multiple three-level electromagnetically induced
transparency (EIT) sub-systems. The polarization rotation angle can be
controlled by a circularly-polarized coupling beam, which breaks the symmetry
in number of EIT subsystems seen by the left- and right-circularly-polarized
components of the weak probe beam. A large polarization rotation angle (up to
45 degrees) has been achieved with a coupling beam power of only 15 mW.
Detailed theoretical analyses including different transition probabilities in
different transitions and Doppler-broadening are presented and the results are
in good agreements with the experimentally measured results.Comment: 28pages, 12figure
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