8,742 research outputs found
Interpretations of galactic center gamma-ray excess confronting the PandaX-II constraints on dark matter-neutron spin-dependent scatterings in the NMSSM
The Weakly Interacting Massive Particle (WIMP) has been one of the most
attractive candidates for Dark Matter (DM), and the lightest neutralino
() in the Next-to-Minimal Supersymmetric Standard Model
(NMSSM) is an interesting realization of WIMP. The Galactic Center Excess (GCE)
can be explained by WIMP DM annihilations in the sky. In this work we consider
the -NMSSM where the singlet and Singlino components
play important roles in the Higgs and DM sector. Guided by our analytical
arguments, we perform a numerical scan over the NMSSM parameter space for the
GCE explanation by considering various observables such as the Standard Model
(SM) Higgs data measured by the ATLAS and CMS experiments, and the -physics
observables and .
We find that the correlation between the coupling in
and the coupling in DM-neutron Spin Dependent (SD)
scattering rate makes all samples we
obtain for GCE explanation get excluded by the PandaX-II results. Although the
DM resonant annihilation scenarios may be beyond the reach of our analytical
approximations and scan strategy, the aforementioned correlation can be a
reasonable motivation for future experiments such as PandaX-nT to further test
the NMSSM interpretation of GCE.Comment: 11 pages, 4 figures, meeting the published version by EPJ
Note: An object detection method for active camera
To solve the problems caused by a changing background during object detection in active camera, this paper proposes a new method based on SURF (speeded up robust features) and data clustering. The SURF feature points of each image are extracted, and each cluster center is calculated by processing the data clustering of k adjacent frames. Templates for each class are obtained by calculating the histograms within the regions around the center points of the clustering classes. The window of the moving object can be located by finding the region that satisfies the histogram matching result between adjacent frames. Experimental results demonstrate that the proposed method can improve the effectiveness of object detection.Yong Chen, Ronghua Zhang, Lei Shang, and Eric H
Sneutrino DM in the NMSSM with inverse seesaw mechanism
In supersymmetric theories like the Next-to-Minimal Supersymmetric Standard
Model (NMSSM), the lightest neutralino with bino or singlino as its dominant
component is customarily taken as dark matter (DM) candidate. Since light
Higgsinos favored by naturalness can strength the couplings of the DM and thus
enhance the DM-nucleon scattering rate, the tension between naturalness and DM
direct detection results becomes more and more acute with the improved
experimental sensitivity. In this work, we extend the NMSSM by inverse seesaw
mechanism to generate neutrino mass, and show that in certain parameter space
the lightest sneutrino may act as a viable DM candidate, i.e. it can annihilate
by multi-channels to get correct relic density and meanwhile satisfy all
experimental constraints. The most striking feature of the extension is that
the DM-nucleon scattering rate can be naturally below its current experimental
bounds regardless of the higgsino mass, and hence it alleviates the tension
between naturalness and DM experiments. Other interesting features include that
the Higgs phenomenology becomes much richer than that of the original NMSSM due
to the relaxed constraints from DM physics and also due to the presence of
extra neutrinos, and that the signatures of sparticles at colliders are quite
different from those with neutralino as DM candidate.Comment: 33 page
End-to-end Structure-Aware Convolutional Networks for Knowledge Base Completion
Knowledge graph embedding has been an active research topic for knowledge
base completion, with progressive improvement from the initial TransE, TransH,
DistMult et al to the current state-of-the-art ConvE. ConvE uses 2D convolution
over embeddings and multiple layers of nonlinear features to model knowledge
graphs. The model can be efficiently trained and scalable to large knowledge
graphs. However, there is no structure enforcement in the embedding space of
ConvE. The recent graph convolutional network (GCN) provides another way of
learning graph node embedding by successfully utilizing graph connectivity
structure. In this work, we propose a novel end-to-end Structure-Aware
Convolutional Network (SACN) that takes the benefit of GCN and ConvE together.
SACN consists of an encoder of a weighted graph convolutional network (WGCN),
and a decoder of a convolutional network called Conv-TransE. WGCN utilizes
knowledge graph node structure, node attributes and edge relation types. It has
learnable weights that adapt the amount of information from neighbors used in
local aggregation, leading to more accurate embeddings of graph nodes. Node
attributes in the graph are represented as additional nodes in the WGCN. The
decoder Conv-TransE enables the state-of-the-art ConvE to be translational
between entities and relations while keeps the same link prediction performance
as ConvE. We demonstrate the effectiveness of the proposed SACN on standard
FB15k-237 and WN18RR datasets, and it gives about 10% relative improvement over
the state-of-the-art ConvE in terms of HITS@1, HITS@3 and [email protected]: The Thirty-Third AAAI Conference on Artificial Intelligence (AAAI
2019
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