146 research outputs found
Banking reforms, performance and risk in China
We investigate the impact of the banking reform started from 2005 on ownership structures in China on commercial banksβ profitability, efficiency and risk over the period 2000β2012, providing comprehensive evidence on the impact of banking reform in China. We find that banks on average tend to have higher profitability, lower risk and lower efficiency after the reforms, and the results are robust with our difference-in-difference approach. Our results also show that the Big 5 state-owned banks (SOCB) underperform banks with other types of ownership when risk is measured by non-performing loans (NPLs) over the entire study period but tend to have fewer NPLs than other banks during the post-reform period. Our results provide some supporting evidence on the ongoing banking reforms in China, suggesting that attracting strategic foreign investors and listing SOCBs on stock exchanges appear to be effective ways to help SOCBs deal with the problem of NPLs and manage their risk
Explaining the DAMPE data with scalar dark matter and gauged interaction
Inspired by the peak structure observed by recent DAMPE experiment in
cosmic-ray spectrum, we consider a scalar dark matter (DM) model with
gauged symmetry, which is the most economical anomaly-free
theory to potentially explain the peak by DM annihilation in nearby subhalo. We
utilize the process , where , , denote the scalar DM,
the new gauge boson and , respectively, to generate the
spectrum. By fitting the predicted spectrum to the experimental data,
we obtain the favored DM mass range and at
Confidence Level (C.L.). Furthermore, we determine the parameter space
of the model which can explain the peak and meanwhile satisfy the constraints
from DM relic abundance, DM direct detection and the collider bounds. We
conclude that the model we consider can account for the peak, although there
exists a tension with the constraints from the LEP-II bound on
arising from the cross section measurement of .Comment: 15 pages, 4 figure
Entropy-Production-Rate-Preserving Algorithms for Thermodynamically Consistent Nonisothermal Models of Incompressible Binary Fluids
We derive a thermodynamically consistent, non-isothermal, hydrodynamic model
for incompressible binary fluids following the generalized Onsager principle
and Boussinesq approximation. This model preserves not only the volume of each
fluid phase but also the positive entropy production rate under
thermodynamically consistent boundary conditions. Guided by the thermodynamical
consistency of the model, a set of second order structure-preserving numerical
algorithms are devised to solve the governing partial differential equations
along with consistent boundary conditions in the model, which preserve the
entropy production rate as well as the volume of each fluid phase at the
discrete level. Several numerical simulations are carried out using an
efficient adaptive time-stepping strategy based on one of the
structure-preserving schemes to simulate the Rayleigh-B\'{e}nard convection in
the binary fluid and interfacial dynamics between two immiscible fluids under
competing effects of the temperature gradient, gravity, and interfacial forces.
Roll cell patterns and thermally induced mixing of binary fluids are observed
in a rectangular region with insulated lateral boundaries and vertical ones
with imposed temperature difference. Long time simulations of interfacial
dynamics are performed demonstrating robust results of new structure-preserving
schemes
Accelerated Light Dark Matter-Earth Inelastic Scattering in Direct Detection
The Earth-stopping effect plays a crucial role in the direct detection of
sub-GeV dark matter. Besides the elastic scattering process, the quasi-elastic
and deep inelastic scatterings between dark matter and nucleus that are usually
neglected can dominate the interaction, especially in the accelerated dark
matter scenarios, which may affect the dark matter detection sensitivity
significantly for the underground experiments. We calculate such inelastic
scattering contributions in the Earth-stopping effect and illustrate the
essence of our argument with the atmospheric dark matter. With the available
data, we find that the resulting upper limits on the atmospheric dark
matter-nucleus scattering cross-section can differ from those only considering
the elastic scattering process by one order of magnitude.Comment: 7 pages, 4 figure
Spin-dependent sub-GeV Inelastic Dark Matter-electron scattering and Migdal effect: (I). Velocity Independent Operator
The ionization signal provide an important avenue of detecting light dark
matter. In this work, we consider the sub-GeV inelastic dark matter and use the
non-relativistic effective field theory (NR-EFT) to derive the constraints on
the spin-dependent DM-electron scattering and DM-nucleus Migdal scattering.
Since the recoil electron spectrum of sub-GeV DM is sensitive to tails of
galactic DM velocity distributions, we also compare the bounds on corresponding
scattering cross sections in Tsallis, Empirical and standard halo models. With
the XENON1T data, we find that the exclusion limits of the DM-proton/neutron
and DM-electron scattering cross sections for exothermic inelastic DM are much
stronger that those for the endothermic inelastic DM. Each limits of the
endothermic inelastic DM can differ by an order of magnitude at most in three
considered DM velocity distributions.Comment: 36 pages, 7 figure
Interpreting the mass anomaly in the vectorlike quark models
The new measurement of -boson mass from the CDF collaboration depicts a
remarkable disagreement with the Standard Model (SM) prediction. This
highly implies that there exist new particles or fields beyond the SM. In this
work, we explore the possibility of explaining the mass anomaly in the
simple extension of the SM with the vector-like quarks. Confronting with the
current LHC data and the electroweak precision measurements, we find that the
vector-like quark models can reconcile SM theory with the mass anomaly
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