2,919 research outputs found
Analysis on Heavy Quarkonia Transitions with Pion Emission in Terms of the QCD Multipole Expansion and Determination of Mass Spectra of Hybrids
One of the most important tasks in high energy physics is search for the
exotic states, such as glueball, hybrid and multi-quark states. The transitions
and attract
great attentions because they may reveal characteristics of hybrids. In this
work, we analyze those transition modes in terms of the theoretical framework
established by Yan and Kuang. It is interesting to notice that the intermediate
states between the two gluon-emissions are hybrids, therefore by fitting the
data, we are able to determine the mass spectra of hybrids. The ground hybrid
states are predicted as 4.23 GeV (for charmonium) and 10.79 GeV (for bottonium)
which do not correspond to any states measured in recent experiments, thus it
may imply that very possibly, hybrids mix with regular quarkonia to constitute
physical states. Comprehensive comparisons of the potentials for hybrids whose
parameters are obtained in this scenario with the lattice results are
presented.Comment: 16 pages, 2 figur
Discovery and Identification of W' and Z' in SU(2) x SU(2) x U(1) Models at the LHC
We explore the discovery potential of W' and Z' boson searches for various
SU(2) x SU(2) x U(1) models at the Large Hadron Collider (LHC), after taking
into account the constraints from low energy precision measurements and direct
searches at both the Tevatron (1.96 TeV) and the LHC (7 TeV). In such models,
the W' and Z' bosons emerge after the electroweak symmetry is spontaneously
broken. Two patterns of the symmetry breaking are considered in this work: one
is SU(2)_L x SU(2)_2 x U(1)_X to SU(2)_L x U(1)_Y (BP-I), another is SU(2)_1 x
SU(2)_2 x U(1)_Y to SU(2)_L x U(1)_Y (BP-II). Examining the single production
channel of W' and Z' with their subsequent leptonic decays, we find that the
probability of detecting W' and Z' bosons in the considered models at the LHC
(with 14 TeV) is highly limited by the low energy precision data constraints.
We show that observing Z' alone, without seeing a W', does not rule out new
physics models with non-Abelian gauge extension, such as the phobic models in
BP-I. Models in BP-II would predict the discovery of degenerate W' and Z'
bosons at the LHC.Comment: 29 pages, including 11 figures, 3 tables, added references for
introductio
Self-Ensemling for 3D Point Cloud Domain Adaption
Recently 3D point cloud learning has been a hot topic in computer vision and
autonomous driving. Due to the fact that it is difficult to manually annotate a
qualitative large-scale 3D point cloud dataset, unsupervised domain adaptation
(UDA) is popular in 3D point cloud learning which aims to transfer the learned
knowledge from the labeled source domain to the unlabeled target domain.
However, the generalization and reconstruction errors caused by domain shift
with simply-learned model are inevitable which substantially hinder the model's
capability from learning good representations. To address these issues, we
propose an end-to-end self-ensembling network (SEN) for 3D point cloud domain
adaption tasks. Generally, our SEN resorts to the advantages of Mean Teacher
and semi-supervised learning, and introduces a soft classification loss and a
consistency loss, aiming to achieve consistent generalization and accurate
reconstruction. In SEN, a student network is kept in a collaborative manner
with supervised learning and self-supervised learning, and a teacher network
conducts temporal consistency to learn useful representations and ensure the
quality of point clouds reconstruction. Extensive experiments on several 3D
point cloud UDA benchmarks show that our SEN outperforms the state-of-the-art
methods on both classification and segmentation tasks. Moreover, further
analysis demonstrates that our SEN also achieves better reconstruction results
Multi-body dynamics modelling on a self-propelled pufferfish with its application in AUV
We developed a Computational Fluid Dynamics (CFD) based tool coupled with a Multi-Body Dynamics (MBD) technique to investigate a self-propelled pufferfish motion within a still water environment. The 3D pufferfish model consists of body, caudal, dorsal and anal fins. The locomotion of fish is entirely determined by the computation and fully induced by the oscillation motion of fish fins. The influence of the phase angle difference on the fish swimming behaviour is examined by varying the angle difference between the caudal, dorsal, and anal fins. The swimming displacement, hydrodynamic force and the wake pattern are analysed
Quantification of the influence of drugs on zebrafish larvae swimming kinematics and energetics
The use of zebrafish larvae has aroused wide interest in the medical field for its potential role in the development of new therapies. The larvae grow extremely quickly and the embryos are nearly transparent which allows easy examination of its internal structures using fluorescent imaging techniques. Medical treatment of zebrafish larvae can directly influence its swimming behaviours. These behaviour changes are related to functional changes of central nervous system and transformations of the zebrafish body such as muscle mechanical power and force variation, which cannot be measured directly by pure experiment observation. To quantify the influence of drugs on zebrafish larvae swimming behaviours and energetics, we have developed a novel methodology to exploit intravital changes based on observed zebrafish locomotion. Specifically, by using an in-house MATLAB code to process the recorded live zebrafish swimming video, the kinematic locomotion equation of a 3D zebrafish larvae was obtained, and a customised Computational Fluid Dynamics tool was used to solve the fluid flow around the fish model which was geometrically the same as experimentally tested zebrafish. The developed methodology was firstly verified against experiment, and further applied to quantify the fish internal body force, torque and power consumption associated with a group of normal zebrafish larvae vs. those immersed in acetic acid and two neuroactive drugs. As indicated by our results, zebrafish larvae immersed in 0.01% acetic acid display approximately 30% higher hydrodynamic power and 10% higher cost of transport than control group. In addition, 500 μM diphenylhydantoin significantly decreases the locomotion activity for approximately 50% lower hydrodynamic power, whereas 100 mg/L yohimbine has not caused any significant influences on 5 dpf zebrafish larvae locomotion. The approach has potential to evaluate the influence of drugs on the aquatic animal’s behaviour changes and thus support the development of new analgesic and neuroactive drugs
Top Quark Forward-Backward Asymmetry and Same-Sign Top Quark Pairs
The top quark forward-backward asymmetry measured at the Tevatron collider
shows a large deviation from standard model expectations. Among possible
interpretations, a non-universal model is of particular interest as
it naturally predicts a top quark in the forward region of large rapidity. To
reproduce the size of the asymmetry, the couplings of the to
standard model quarks must be large, inevitably leading to copious production
of same-sign top quark pairs at the energies of the Large Hadron Collider
(LHC). We explore the discovery potential for and production in
early LHC experiments at 7-8 TeV and conclude that if {\it no} signal is
observed with 1 fb of integrated luminosity, then a non-universal
alone cannot explain the Tevatron forward-backward asymmetry.Comment: Tevatron limit from same-sign tt search adde
Bid Optimization by Multivariable Control in Display Advertising
Real-Time Bidding (RTB) is an important paradigm in display advertising,
where advertisers utilize extended information and algorithms served by Demand
Side Platforms (DSPs) to improve advertising performance. A common problem for
DSPs is to help advertisers gain as much value as possible with budget
constraints. However, advertisers would routinely add certain key performance
indicator (KPI) constraints that the advertising campaign must meet due to
practical reasons. In this paper, we study the common case where advertisers
aim to maximize the quantity of conversions, and set cost-per-click (CPC) as a
KPI constraint. We convert such a problem into a linear programming problem and
leverage the primal-dual method to derive the optimal bidding strategy. To
address the applicability issue, we propose a feedback control-based solution
and devise the multivariable control system. The empirical study based on
real-word data from Taobao.com verifies the effectiveness and superiority of
our approach compared with the state of the art in the industry practices
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