7,448 research outputs found

    Detecting top-Higgs at high energy e+ee^{+}e^{-} colliders

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    We calculate the contributions of the top-Higgs ht0h_{t}^{0} predicted by topcolor assisted technicolor(TC2) models to e+etcνeνee^{+}e^{-}\longrightarrow \overline{t}c\overline{\nu}_{e}\nu_{e} and compare the results with the contributions of ht0h^{0}_{t} to the processes e+eZht0Ztce^{+}e^{-}\longrightarrow Z h^{0}_{t}\longrightarrow Z\overline{t}c and e+eγht0γtce^+e^-\longrightarrow \gamma h^{0}_{t} \longrightarrow \gamma \overline{t}c. We find that e+etcνeνee^{+}e^{-} \longrightarrow\overline{t}c\overline{\nu}_{e}\nu_{e} is very sensitive to ht0h^{0}_{t}, which can be easy detected via this process at high-energy e+ee^{+}e^{-} collider(LC) experiments with s500\sqrt{s}\geq 500 GeVGeV, as long as its mass below the tt\overline{t}t threshold. The process e+eγtce^{+}e^{-} \longrightarrow \gamma\overline{t}c also can be used to detect ht0h^{0}_{t} at LC experiments.Comment: latex file, 10 pages, 4 eps figure, submitted to Phys. Lett.

    Neutral top-pion and top-charm production in high energy e+ee^{+}e^{-} collisions

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    We calculate the contributions of the neutral top-pion, predicted by topcolor-assisted technicolor (TC2) theory, to top-charm production via the processes γγtˉc\gamma\gamma \longrightarrow\bar{t}c and e+eγγtˉce^{+}e^{-}\longrightarrow \gamma\gamma\longrightarrow \bar{t}c at the high energy linear e+ee^{+}e^{-} collider (LC) experiments. The cross section is of order 102pb10^{-2}pb in most of the parameter space of TC2 theory, which may be detected at the LC experiments. So the process e+etˉce^{+}e^{-}\longrightarrow \bar{t}c can be used to detect the signature of TC2 theory.Comment: Latex file, 8 pages with 4 eps figures. to be published Phys.Lett.

    Modeling the Resource Requirements of Convolutional Neural Networks on Mobile Devices

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    Convolutional Neural Networks (CNNs) have revolutionized the research in computer vision, due to their ability to capture complex patterns, resulting in high inference accuracies. However, the increasingly complex nature of these neural networks means that they are particularly suited for server computers with powerful GPUs. We envision that deep learning applications will be eventually and widely deployed on mobile devices, e.g., smartphones, self-driving cars, and drones. Therefore, in this paper, we aim to understand the resource requirements (time, memory) of CNNs on mobile devices. First, by deploying several popular CNNs on mobile CPUs and GPUs, we measure and analyze the performance and resource usage for every layer of the CNNs. Our findings point out the potential ways of optimizing the performance on mobile devices. Second, we model the resource requirements of the different CNN computations. Finally, based on the measurement, pro ling, and modeling, we build and evaluate our modeling tool, Augur, which takes a CNN configuration (descriptor) as the input and estimates the compute time and resource usage of the CNN, to give insights about whether and how e ciently a CNN can be run on a given mobile platform. In doing so Augur tackles several challenges: (i) how to overcome pro ling and measurement overhead; (ii) how to capture the variance in different mobile platforms with different processors, memory, and cache sizes; and (iii) how to account for the variance in the number, type and size of layers of the different CNN configurations

    The flavor-changing rare top decays tcVVt\to c V V in topcolor-assisted technicolor theory

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    In the framework of topcolor-assisted technicolor (TC2) theory, we calculate the contributions of the scalars(the neutral top-pion πt0\pi_{t}^{0} and the top-Higgs ht0h_{t}^{0}) to the flavor-changing rare top decays tcVVt\to c V V(V= W, g, γ\gamma or Z). Our results show that ht0h_{t}^{0} can enhance the standard model BrSM(tcWW)B_{r}^{SM}(t\longrightarrow cWW) by several orders of magnitude for most of the parameter space. The peak of the branching ratio resonance emerges when the top-Higgs mass is between 2mW2m_{W} and mtm_{t}. The branching ratio Br(tcWW) B_{r}(t\to c W W) can reach 103 10^{-3} in the narrow range.Comment: Latex file, 11pages, 2 eps figure

    Probing neutral top-pion via a flavor-changing process γγtcˉΠt0\gamma\gamma\to t\bar{c}\Pi_{t}^{0}

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    In the framework of topcolor-assisted-technicolor model(TC2), we study a flavor-changing neutral top-pion production process γγtcˉΠt0\gamma\gamma\to t\bar{c}\Pi_{t}^{0}. The study shows that there exists a resonance effect which can enhance the cross section up to a few fb even tens fb. For a yearly luminosity 100 fb1fb^{-1} at future linear colliders, there might be hundreds even thousands events to be produced. On the other hand, the background of such flavor-changing process is very clean due to the GIM mechanism in SM . With such sufficient events and clean background, neutral toppion could be detected at future linear colliders with high center of energy and luminosity. Our study provides a possible way to test TC2 model.Comment: 10 pages, 4 figures,has been accepted by Phys.Rev.

    The rare top quark decays tcVt\to cV in the topcolor-assisted technicolor model

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    We consider the rare top quark decays in the framework of topcolor-assisted technicolor (TC2) model. We find that the contributions of top-pions and top-Higgs predicted by the TC2 model can enhance the SM branching ratios by as much as 6-9 orders of magnitude. i.e., in the most case, the orders of magnitude of branching ratios are Br(tcg)105Br(t\to c g)\sim 10^{-5}, Br(tcZ)105Br(t\to c Z)\sim 10^{-5}, Br(tcγ)107Br(t\to c \gamma)\sim 10^{-7}. With the reasonable values of the parameters in TC2 model, such rare top quark decays may be testable in the future experiments. So, rare top quark decays provide us a unique way to test TC2 model.Comment: 14 pages, 4 figure

    Rare decays B\to M\nu\bar{\nu} in the TC2 model and the LHT model

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    In the framework of the topcolor-assisted technicolor (TC2TC2) model and the littlest Higgs model with TT-parity (LHTLHT model), we consider the rare B decays BMννˉB\to M\nu\bar{\nu} with M=π,K,ρ,M=\pi,K,\rho, or KK^{\ast}. We find that the contributions of the TC2TC2 model to the branching ratios of these decay processes are larger than those for the LHTLHT model. The experimental upper limits for some branching ratios can give severe constraints on the free parameters of the TC2TC2 model.Comment: 25 pages, 7 figure

    The productions of the top-pions and top-Higgs associated with the charm quark at the hadron colliders

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    In the topcolor-assistant technicolor (TC2) model, the typical physical particles, top-pions and top-Higgs, are predicted and the existence of these particles could be regarded as the robust evidence of the model. These particles are accessible at the Tevatron and LHC, and furthermore the flavor-changing(FC) feature of the TC2 model can provide us a unique chance to probe them. In this paper, we study some interesting FC production processes of top-pions and top-Higgs at the Tevatron and LHC, i.e., cΠtc\Pi_{t}^{-} and cΠt0(ht0)c\Pi_{t}^{0}(h_{t}^{0}) productions. We find that the light charged top-pions are not favorable by the Tevatron experiments and the Tevatron has a little capability to probe neutral top-pion and top-Higgs via these FC production processes. At the LHC, however, the cross section can reach the level of 1010010\sim 100 pb for cΠtc\Pi_t^- production and 10100 10\sim 100 fb for cΠt0(ht0)c\Pi_t^0(h_t^0) production. So one can expect that enough signals could be produced at the LHC experiments. Furthermore, the SM background should be clean due to the FC feature of the processes and the FC decay modes Πtbcˉ,Πt0(ht0)tcˉ\Pi_t^-\to b\bar{c}, \Pi_t^0(h_t^0)\to t\bar{c} can provide us the typical signal to detect the top-pions and top-Higgs. Therefore, it is hopeful to find the signal of top-pions and top-Higgs with the running of the LHC via these FC processes.Comment: 12 pages, 6 figure

    Production and decay of the neutral top-pion in high energy e+ee^{+}e^{-} colliders

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    We study the production and decay of the neutral top-pion πt0\pi_{t}^{0} predicted by topcolor-assisted technicolor(TC2) theory. Our results show that, except the dominant decay modes bbˉb\bar{b}, tˉc\bar{t}c and gggg, the πt0\pi_{t}^{0} can also decay into γγ\gamma\gamma and ZγZ \gamma modes. It can be significantly produced at high energy e+ee^{+}e^{-} collider(LC) experiments via the processes e+eπt0γe^{+}e^{-}\to \pi_{t}^{0}\gamma and e+eZπt0e^{+}e^{-}\to Z\pi_{t}^{0}. We further calculate the production cross sections of the processes e+eγπt0γtˉce^{+}e^{-}\to\gamma\pi_{t}^{0}\to\gamma\bar{t}c and e+eZπt0Ztˉce^{+}e^{-}\to Z\pi_{t}^{0}\to Z\bar{t}c. We find that the signatures of the neutral top-pion πt0\pi_{t}^{0} can be detected via these processes.Comment: Latex file, 13 Pages, 6 eps figures. to be published in Phys.Rev.
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