31,923 research outputs found
Semiparametric Additive Transformation Model under Current Status Data
We consider the efficient estimation of the semiparametric additive
transformation model with current status data. A wide range of survival models
and econometric models can be incorporated into this general transformation
framework. We apply the B-spline approach to simultaneously estimate the linear
regression vector, the nondecreasing transformation function, and a set of
nonparametric regression functions. We show that the parametric estimate is
semiparametric efficient in the presence of multiple nonparametric nuisance
functions. An explicit consistent B-spline estimate of the asymptotic variance
is also provided. All nonparametric estimates are smooth, and shown to be
uniformly consistent and have faster than cubic rate of convergence.
Interestingly, we observe the convergence rate interfere phenomenon, i.e., the
convergence rates of B-spline estimators are all slowed down to equal the
slowest one. The constrained optimization is not required in our
implementation. Numerical results are used to illustrate the finite sample
performance of the proposed estimators.Comment: 32 pages, 5 figure
The production of neutral resonance with hidden beauty from scattering
We investigate the discovery potential of the predicted neutral hidden beauty
resonance through scattering within an effective
Lagrangian approach. Two reactions and
are studied in this work, with nucleon pole
exchange as the background. It is found that the contributions of the
resonance give clear peak structures in the magnitude of 1
near the threshold of the in the total cross sections. The
numerical results indicate that the center of mass energy 11-11.1 GeV
would be a best energy window for searching the resonance, where
the signal can be easily distinguished from the background. The
COMPASS experiment at CERN's Super Proton Synchrotron (SPS) with pion beam of
280 GeV will be an ideal platform for searching the super-heavy
resonance with hidden beauty, which is hopeful to test the theoretical results
Multi-kink topological terms and charge-binding domain-wall condensation induced symmetry-protected topological states: Beyond Chern-Simons/BF theory
Quantum-disordering a discrete-symmetry breaking state by condensing
domain-walls can lead to a trivial symmetric insulator state. In this work, we
show that if we bind a 1D representation of the symmetry (such as a charge) to
the intersection point of several domain walls, condensing such modified
domain-walls can lead to a non-trivial symmetry-protected topological (SPT)
state. This result is obtained by showing that the modified domain-wall
condensed state has a non-trivial SPT invariant -- the symmetry-twist dependent
partition function. We propose two different kinds of field theories that can
describe the above mentioned SPT states. The first one is a
Ginzburg-Landau-type non-linear sigma model theory, but with an additional
multi-kink domain-wall topological term. Such theory has an anomalous
symmetry but an anomaly-free symmetry. The second one is a gauge
theory, which is beyond Abelian Chern-Simons/BF gauge theories. We argue that
the two field theories are equivalent at low energies. After coupling to the
symmetry twists, both theories produce the desired SPT invariant.Comment: 22 pages, 8 figures, symmetry transformaition for the Ginzburg-Landau
NLM is added in the introduction part, references adde
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