2,071 research outputs found
Computation of the coefficients for order anomalous chiral Lagrangian
We present the results of computing the order low energy constants in
the anomalous part of chiral Lagrangian both for two and three flavor
pseudoscalar mesons. This is a generalization of our previous work on
calculating the order coefficients for the normal part chiral Lagrangian
in terms of the quark self energy . We show that most of our
results are consistent with those we can find in the literature.Comment: 20 page
Computation of the order low-energy constants with tensor sources
We present the results of calculations of the and order
low-energy constants for the chiral Lagrangian with tensor sources for both two
and three flavors of pseudoscalar mesons. This is a generalization of our
previous work on similar calculations without tensor sources in terms of the
quark self-energy , based on the first principle derivation of the
low-energy effective Lagrangian and computation of the low-energy constants
with some rough approximations. With the help of partial integration and some
epsilon relations, we find that some order operators with tensor sources
appearing in the literature are related to each other. That leaves 98
independent terms for -flavor, 92 terms for three-flavor, and 65 terms for
two-flavor cases. We also find that the odd-intrinsic-parity chiral Lagrangian
with tensor sources cannot independently exist in any order of low-energy
expansion.Comment: 29 page
Dynamical Computation on Coefficients of Electroweak Chiral Lagrangian from One-doublet and Topcolor-assisted Technicolor Models
Based on previous studies deriving the chiral Lagrangian for pseudo scalar
mesons from the first principle of QCD, we derive the electroweak chiral
Lagrangian and build up a formulation for computing its coefficients from
one-doublet technicolor model and a schematic topcolor-assisted technicolor
model. We find that the coefficients of the electroweak chiral Lagrangian for
the topcolor-assisted technicolor model are divided into three parts: direct
TC2 interaction part, TC1 and TC2 induced effective Z' particle contribution
part, and ordinary quarks contribution part. The first two parts are computed
in this paper and we show that the direct TC2 interaction part is the same as
that in the one-doublet technicolor model, while effective Z' contributions are
at least proportional to the p^2 order parameter \beta_1 in the electroweak
chiral Lagrangian and typical features of topcolor-assisted technicolor model
are that it only allows positive T and U parameters and the T parameter varies
in the range 0\sim 1/(25\alpha), the upper bound of T parameter will decrease
as long as Z' mass become large. The S parameter can be either positive or
negative depending on whether the Z' mass is large or small. The Z' mass is
also bounded above and the upper bound depend on value of T parameter. We
obtain the values for all the coefficients of the electroweak chiral Lagrangian
up to order of p^4.Comment: 52 pages, 15 figure
Learning to Sample: an Active Learning Framework
Meta-learning algorithms for active learning are emerging as a promising
paradigm for learning the ``best'' active learning strategy. However, current
learning-based active learning approaches still require sufficient training
data so as to generalize meta-learning models for active learning. This is
contrary to the nature of active learning which typically starts with a small
number of labeled samples. The unavailability of large amounts of labeled
samples for training meta-learning models would inevitably lead to poor
performance (e.g., instabilities and overfitting). In our paper, we tackle
these issues by proposing a novel learning-based active learning framework,
called Learning To Sample (LTS). This framework has two key components: a
sampling model and a boosting model, which can mutually learn from each other
in iterations to improve the performance of each other. Within this framework,
the sampling model incorporates uncertainty sampling and diversity sampling
into a unified process for optimization, enabling us to actively select the
most representative and informative samples based on an optimized integration
of uncertainty and diversity. To evaluate the effectiveness of the LTS
framework, we have conducted extensive experiments on three different
classification tasks: image classification, salary level prediction, and entity
resolution. The experimental results show that our LTS framework significantly
outperforms all the baselines when the label budget is limited, especially for
datasets with highly imbalanced classes. In addition to this, our LTS framework
can effectively tackle the cold start problem occurring in many existing active
learning approaches.Comment: Accepted by ICDM'1
Derivation of Electroweak Chiral Lagrangian from One Family Technicolor Model
Based on previous studies deriving the chiral Lagrangian for pseudo scalar
mesons from the first principle of QCD in the path integral formalism, we
derive the electroweak chiral Lagrangian and dynamically compute all its
coefficients from the one family technicolor model. The numerical results of
the order coefficients obtained in this paper are proportional to the
technicolor number and the technifermion number ,
which agrees with the arguments in previous works, and which confirms the
reliability of this dynamical computation.Comment: 6 page
Electroweak Chiral Lagrangian for a Hypercharge-universal Topcolor Model
Electroweak chiral Lagrangian for a hypercharge-universal topcolor model is
investigated. We find that the assignments of universal hypercharge improve the
results obtained previously from K.Lane's prototype natural TC2 model by
allowing a larger Z' mass resulting in a very small T parameter and the S
parameter is still around the order of +1Comment: 12 pages, 7 figure
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