Exclusive rare Bs→(K,η,η′)ℓ+ℓ−B_s\to (K,\eta,\eta')\ell^+\ell^- decays in the light-front quark model

Using the light-front quark model, we calculate the transition form factors, decay rates, and longitudinal lepton polarization asymmetries for the exclusive rare $B_s\to (K,\eta^{(\prime)})(\ell^+\ell^-,\nu_{\ell}\bar{\nu_{\ell}}$ ($\ell=e,\mu,\tau$) decays within the standard model, taking into account the $\eta-\eta'$ mixing angle. For the mixing angle $\theta=-20^{\circ}$ ($-10^{\circ}$) in the octet-singlet basis, we obtain ${\rm BR}(B_s\to \eta\sum\nu_{\ell}\bar{\nu}_{\ell})=1.1 (1.7)\times 10^{-6}$, ${\rm BR}(B_s\to \eta\mu^+\mu^-)=1.5 (2.4)\times 10^{-7}$, ${\rm BR}(B_s\to \eta\tau^+\tau^-)=3.8 (5.8)\times 10^{-8}$, ${\rm BR}(B_s\to \eta'\sum\nu_{\ell}\bar{\nu}_{\ell})=1.8 (1.3)\times 10^{-6}$, ${\rm BR}(B_s\to \eta'\mu^+\mu^-)=2.4 (1.8)\times 10^{-7}$, and ${\rm BR}(B_s\to \eta'\tau^+\tau^-)=3.4 (2.6)\times 10^{-8}$, respectively. The branching ratios for the $B_s\to K(\nu_{\ell}\bar{\nu_{\ell}},\ell^+\ell^-)$ decays are at least an order of magnitude smaller than those for the $B_s\to \eta^{(\prime)}(\nu_{\ell}\bar{\nu_{\ell}},\ell^+\ell^-)$ decays. The averaged values of the lepton polarization asymmetries for $B_s\to (K,\eta^{(\prime)})\ell^+\ell^-$ are obtained as \la P^K_L\ra_\mu=\la P^\eta_L\ra_\mu=\la P^{\eta'}_L\ra_\mu=-0.98, \la P^K_L\ra_\tau=-0.24, \la P^\eta_L\ra_\tau=-0.20 and \la P^{\eta'}_L\ra_\tau=-0.14, respectively.Comment: 20 pages, 6 figures, minor revision. version to appear in Journal of Physics

Hypergraph Transformer for Skeleton-based Action Recognition

Skeleton-based action recognition aims to predict human actions given humanjoint coordinates with skeletal interconnections. To model such off-grid datapoints and their co-occurrences, Transformer-based formulations would be anatural choice. However, Transformers still lag behind state-of-the-art methodsusing graph convolutional networks (GCNs). Transformers assume that the inputis permutation-invariant and homogeneous (partially alleviated by positionalencoding), which ignores an important characteristic of skeleton data, i.e.,bone connectivity. Furthermore, each type of body joint has a clear physicalmeaning in human motion, i.e., motion retains an intrinsic relationshipregardless of the joint coordinates, which is not explored in Transformers. Infact, certain re-occurring groups of body joints are often involved in specificactions, such as the subconscious hand movement for keeping balance. Vanillaattention is incapable of describing such underlying relations that arepersistent and beyond pair-wise. In this work, we aim to exploit these uniqueaspects of skeleton data to close the performance gap between Transformers andGCNs. Specifically, we propose a new self-attention (SA) extension, namedHypergraph Self-Attention (HyperSA), to incorporate inherently higher-orderrelations into the model. The K-hop relative positional embeddings are alsoemployed to take bone connectivity into account. We name the resulting modelHyperformer, and it achieves comparable or better performance w.r.t. accuracyand efficiency than state-of-the-art GCN architectures on NTU RGB+D, NTU RGB+D120, and Northwestern-UCLA datasets. On the largest NTU RGB+D 120 dataset, thesignificantly improved performance reached by our Hyperformer demonstrates theunderestimated potential of Transformer models in this field.<br

Wrist movement detector for ROS based control of the robotic hand

Robotic hands are used in a wide range of applications. They have many different shapes, constructions and capabilities. This work presents a new design of a robotic hand using tailor-made as well as widely available sensors and actuators. The information transferred between the sensor and actuators is processed using the Robot Operating System (ROS) topic mechanism. The robotic hand movement is remotely controlled by a movement detector mounted on the wrist of a human hand controller. Based on this simple hardware setup we demonstrate that the robotic hand can be remotely opened and closed thereby allowing to grasp objects flexibly

A New Method for Riccati Differential Equations Based on Reproducing Kernel and Quasilinearization Methods

We introduce a new method for solving Riccati differential equations, which is based on reproducing kernel method and quasilinearization technique. The quasilinearization technique is used to reduce the Riccati differential equation to a sequence of linear problems. The resulting sets of differential equations are treated by using reproducing kernel method. The solutions of Riccati differential equations obtained using many existing methods give good approximations only in the neighborhood of the initial position. However, the solutions obtained using the present method give good approximations in a larger interval, rather than a local vicinity of the initial position. Numerical results compared with other methods show that the method is simple and effective

Isotopic constraints on the role of hypohalous acids in sulfate aerosol formation in the remote marine boundary layer

Sulfate is an important component of global atmospheric aerosol, and has partially compensated for greenhouse gas-induced warming during the industrial period. The magnitude of direct and indirect radiative forcing of aerosols since preindustrial times is a large uncertainty in climate models, which has been attributed largely to uncertainties in the preindustrial environment. Here, we report observations of the oxygen isotopic composition (Δ¹⁷O) of sulfate aerosol collected in the remote marine boundary layer (MBL) in spring and summer in order to evaluate sulfate production mechanisms in pristine-like environments. Model-aided analysis of the observations suggests that 33–50 % of sulfate in the MBL is formed via oxidation by hypohalous acids (HOX  =  HOBr + HOCl), a production mechanism typically excluded in large-scale models due to uncertainties in the reaction rates, which are due mainly to uncertainties in reactive halogen concentrations. Based on the estimated fraction of sulfate formed via HOX oxidation, we further estimate that daily-averaged HOX mixing ratios on the order of 0.01–0.1 parts per trillion (ppt  =  pmol/mol) in the remote MBL during spring and summer are sufficient to explain the observations

A review of age estimation research to evaluate its inclusion in automated child pornography detection

The uses of artificial intelligence (AI) today seem limitless. It has helped organisations understand their customers more, provide them with better, more tailored services, and helped people with disabilities understand the world they previously could not. There are also many areas of current research for the use of AI. Aiding law-enforcement when they must analyse evidence of an indecent nature is one example where the use of AI, if successful, could enhance detection of indecent images and also reduce the workload and stress on the law enforcement staff employed in such activities. Working with indecent images of minors is particularly stressful. This paper reviews the current stage at which artificial intelligence finds itself when estimating a person’s age. By reviewing its accuracy, it is possible to evaluate the feasibility of its inclusion in an artificial-intelligence-aided evidence analysis tool. With artificial intelligence currently capable of estimating a person’s age to within a few years, its incorporation would most certainly allow photographs to be analysed and flagged if anyone is suspected of being underage

Finite dimensional integrable Hamiltonian systems associated with DSI equation by Bargmann constraints

The Davey-Stewartson I equation is a typical integrable equation in 2+1 dimensions. Its Lax system being essentially in 1+1 dimensional form has been found through nonlinearization from 2+1 dimensions to 1+1 dimensions. In the present paper, this essentially 1+1 dimensional Lax system is further nonlinearized into 1+0 dimensional Hamiltonian systems by taking the Bargmann constraints. It is shown that the resulting 1+0 dimensional Hamiltonian systems are completely integrable in Liouville sense by finding a full set of integrals of motion and proving their functional independence.Comment: 10 pages, in LaTeX, to be published in J. Phys. Soc. Jpn. 70 (2001