1,849 research outputs found
Off-shell photon distribution amplitudes in the low-energy effective theory of QCD
Based on the principle of the Lorentz covariance the transition matrix
elements from an off-shell photon state to the vacuum are decomposed into the
light-cone photon DAs, in which only two transversal DAs survive in the
on-shell limit. The eight off-shell light-cone photon distribution amplitudes
(DAs) corresponding to chiral-odd and chiral-even up to twist-four and the
corresponding coupling constants are studied systematically in the instanton
vacuum model of quantum chromodynamics (QCD). The various individual photon DA
multiplied by its corresponding coupling constant is expressed in terms of the
correlation functions, which are connected with the spectral densities of an
effective quark propagator, and then evaluated in the low-energy effective
theory derived from the instanton vacuum model of QCD. The explicit analytical
expressions and the numerical results for the photon DAs and their coupling
constants are given
Temperature Dependence of the Effective Bag Constant and the Radius of a Nucleon in the Global Color Symmetry Model of QCD
We study the temperature dependence of the effective bag constant, the mass,
and the radius of a nucleon in the formalism of the simple global color
symmetry model in the Dyson-Schwinger equation approach of QCD with a
Gaussian-type effective gluon propagator. We obtain that, as the temperature is
lower than a critical value, the effective bag constant and the mass decrease
and the radius increases with the temperature increasing. As the critical
temperature is reached, the effective bag constant and the mass vanish and the
radius tends to infinity. At the same time, the chiral quark condensate
disappears. These phenomena indicate that the deconfinement and the chiral
symmetry restoration phase transitions can take place at high temperature. The
dependence of the critical temperature on the interaction strength parameter in
the effective gluon propagator of the approach is given.Comment: 10 pages, 9 figure
Generation of Two-Flavor Vortex Atom Laser from a Five-State Medium
Two-flavor atom laser in a vortex state is obtained and analyzed via
electromagnetically induced transparency (EIT) technique in a five-level
type system by using two probe lights with -directional orbital angular
momentum , respectively. Together with the original transfer
technique of quantum states from light to matter waves, the present result can
be extended to generate continuous two-flavor vortex atom laser with
non-classical atoms.Comment: 5 pages, 1 figure; The previous version (v2) is a wrong one; this is
the published versio
Dynamics of Domain Wall in a Biaxial Ferromagnet With Spin-torque
The dynamics of the domain wall (DW) in a biaxial ferromagnet interacting
with a spin-polarized current are described by sine-gordon (SG) equation
coupled with Gilbert damping term in this paper. Within our frame-work of this
model, we obtain a threshold of the current in the motion of a single DW with
the perturbation theory on kink soliton solution to the corresponding
ferromagnetic system, and the threshold is shown to be dependent on the Gilbert
damping term. Also, the motion properties of the DW are discussed for the zero-
and nonzero-damping cases, which shows that our theory to describe the dynamics
of the DW are self-consistent.Comment: 7pages, 3figure
Tree of Uncertain Thoughts Reasoning for Large Language Models
While the recently introduced Tree of Thoughts (ToT) has heralded
advancements in allowing Large Language Models (LLMs) to reason through
foresight and backtracking for global decision-making, it has overlooked the
inherent local uncertainties in intermediate decision points or "thoughts".
These local uncertainties, intrinsic to LLMs given their potential for diverse
responses, remain a significant concern in the reasoning process. Addressing
this pivotal gap, we introduce the Tree of Uncertain Thoughts (TouT) - a
reasoning framework tailored for LLMs. Our TouT effectively leverages Monte
Carlo Dropout to quantify uncertainty scores associated with LLMs' diverse
local responses at these intermediate steps. By marrying this local uncertainty
quantification with global search algorithms, TouT enhances the model's
precision in response generation. We substantiate our approach with rigorous
experiments on two demanding planning tasks: Game of 24 and Mini Crosswords.
The empirical evidence underscores TouT's superiority over both ToT and
chain-of-thought prompting methods
Performance of electronic dispersion compensator for 10Gb/s multimode fiber links
In high-speed optical links, electronic compensation circuits can be utilized to greatly improve the data transmission performance limited by fiber dispersion. In this paper, we develop a full link model, including
multimode fibers, optical/electronics/optical components, clock-and-data recovery and electronic compensation circuits. The performance of various electronic compensation techniques, such as feed-forward equalizer and decision feedback equalizer for optical multimode fiber is investigated and numerically evaluated. Finally, a comparison of the performance of each compensation techniques and a proposal of optimal equalizer circuit implementation, achieving a 10-Gb/s transmission over 1-km standard multimode fiber are presented
- …