3,066 research outputs found
QBDT, a new boosting decision tree method with systematic uncertainties into training for High Energy Physics
A new boosting decision tree (BDT) method, QBDT, is proposed for the
classification problem in the field of high energy physics (HEP). In many HEP
researches, great efforts are made to increase the signal significance with the
presence of huge background and various systematical uncertainties. Why not
develop a BDT method targeting the significance directly? Indeed, the
significance plays a central role in this new method. It is used to split a
node in building a tree and to be also the weight contributing to the BDT
score. As the systematical uncertainties can be easily included in the
significance calculation, this method is able to learn about reducing the
effect of the systematical uncertainties via training. Taking the search of the
rare radiative Higgs decay in proton-proton collisions as example, QBDT and the popular Gradient BDT (GradBDT)
method are compared. QBDT is found to reduce the correlation between the signal
strength and systematical uncertainty sources and thus to give a better
significance. The contribution to the signal strength uncertainty from the
systematical uncertainty sources using the new method is 50-85~\% of that using
the GradBDT method.Comment: 29 pages, accepted for publication in NIMA, algorithm available at
https://github.com/xialigang/QBD
Analysis of the tensor-tensor type scalar tetraquark states with QCD sum rules
In this article, we study the ground states and the first radial excited
states of the tensor-tensor type scalar hidden-charm tetraquark states with the
QCD sum rules. We separate the ground state contributions from the first radial
excited state contributions unambiguously, and obtain the QCD sum rules for the
ground states and the first radial excited states, respectively. Then we search
for the Borel parameters and continuum threshold parameters according to four
criteria and obtain the masses of the tensor-tensor type scalar hidden-charm
tetraquark states, which can be confronted to the experimental data in the
future.Comment: 12 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1607.0484
The decay width of the as an axialvector tetraquark state in solid quark-hadron duality
In this article, we tentatively assign the to be the
diquark-antidiquark type axialvector tetraquark state, study the hadronic
coupling constants , , with the QCD sum rules in details. We take into account both the
connected and disconnected Feynman diagrams in carrying out the operator
product expansion, as the connected Feynman diagrams alone cannot do the work.
Special attentions are paid to matching the hadron side of the correlation
functions with the QCD side of the correlation functions to obtain solid
duality, the routine can be applied to study other hadronic couplings directly.
We study the two-body strong decays ,
, , and obtain the total
width of the . The numerical results support assigning the
to be the diquark-antidiquark type axialvector tetraquark
state, and assigning the to be the meson-meson type axialvector
molecular state.Comment: 16 pages, 3 figure
Texture Synthesis Through Convolutional Neural Networks and Spectrum Constraints
This paper presents a significant improvement for the synthesis of texture
images using convolutional neural networks (CNNs), making use of constraints on
the Fourier spectrum of the results. More precisely, the texture synthesis is
regarded as a constrained optimization problem, with constraints conditioning
both the Fourier spectrum and statistical features learned by CNNs. In contrast
with existing methods, the presented method inherits from previous CNN
approaches the ability to depict local structures and fine scale details, and
at the same time yields coherent large scale structures, even in the case of
quasi-periodic images. This is done at no extra computational cost. Synthesis
experiments on various images show a clear improvement compared to a recent
state-of-the art method relying on CNN constraints only
- β¦