13,679 research outputs found

    Implications for new physics from Bˉ0π0π0{\bar B}^0\to \pi^0\pi^0 and Bˉ0Kˉ0K0{\bar B}^0\to {\bar K}^0K^0

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    We have analyzed the Bˉ0π0π0{\bar B}^0\to \pi^0\pi^0 puzzle in three kinds of models beyond the standard model (SM). It is shown that the minimal flavor violation (MFV) models, the minimal supersymmetric standard model (MSSM), and the two Higgs doublet models (2HDM) I and II can not give an explanation of the Bˉ0π0π0{\bar B}^0\to \pi^0\pi^0 puzzle within 1σ1 \sigma experimental bounds and the model III 2HDM can explain the puzzle without a conflict with other experimental measurements. If the constraint on C8gC_{8g} from bsgb\to s g is not imposed, for all kinds of insertions considered there are regions of parameter space, where the scalar quark mass is larger (much larger) than the gluino mass in the case of LR or RL (LL or RR), in which the puzzle can be resolved within 1σ1 \sigma experimental bounds.Comment: 7 pages, 3 eps files. Add some more explicit analysis version appeared in PL

    Singlet Charge 2/32/3 Quark hiding the Top: Tevatron and LEP Implications

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    If cc and tt quarks are strongly mixed with a weak singlet charge 2/32/3 quark, BR(tν+X)BR(t\to \ell\nu + X) could be suppressed via the tcH0t\to cH^0 mode, thereby the top quark could still hide below MWM_W, whereas the heavy quark signal observed at the Tevatron is due to the dominantly singlet quark QQ. This may occur without affecting the small mcm_c value. Demanding mQ175m_Q \simeq 175 GeV and m_t \ltap M_W, we find that BR(tν+X)BR(t\to \ell\nu + X) cannot be too suppressed. The heavy quark QQ decays via W, HW,\ H, and ZZ bosons. The latter can lead to bb-tagged Z+4Z + 4 jet events, while the strong cc--QQ mixing is reflected in sizable QsWQ\to sW fraction. ZtcˉZ\to t\bar c decay occurs at tree level and may be at the 10310^{-3} order, leading to the signature of ZνbcˉZ\to \ell\nu b\bar c, all isolated and with large pTp_T, at 10510^{-5} order.Comment: 10 pages + 3 Figures (not included), ReVTeX, NTUTH-94-1

    Heavy Baryonic Decays of \Lambda_b \to \Lambda \eta^{(\prime)} and Nonspectator Contribution

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    We calculate the branching ratios of the hadronic \Lambda_b decays to \eta and \eta^\prime in the factorization approximation where the form factors are estimated via QCD sum rules and the pole model. Our results indicate that, contrary to B\to K\eta^{(\prime)} decays, the branching ratios for \Lambda_b\to\Lambda\eta and \Lambda_b\to\Lambda\eta^\prime are more or less the same in the hadronic \Lambda_b transitions. We estimate the branching ratio of \Lambda_b\to\Lambda\eta^{(\prime)} to be 10.80 (10.32)\times 10^{-6} in QCD sum rules, and 2.78 (2.96)\times 10^{-6} in the pole model. We also estimate the nonfactorizable gluon fusion contribution to \Lambda_b\to\Lambda\eta^\prime decay by dividing this process into strong and weak vertices. Our results point to an enhancement of more than an order of magnitude due to this mechanism.Comment: 16 pages, ReVTeX, 5 eps figure

    Exploring Evaluation Factors and Framework for the Object of Automated Trading System

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    Automated trading system (ATS) is a computer program that combines different trading rules to find optimal trading opportunities. The objects of ATS, which are financial assets, need evaluation because that is of great significance for stakeholders and market orders. From the perspectives of dealers, agents, external environment, and objects themselves, this study explored factors in evaluating and choosing the object of ATS. Based on design science research (DSR), we presented a preliminary evaluation framework and conducted semi-structured interviews with twelve trading participants engaged in different occupations. By analyzing the data collected, we validated eight factors from literatures and found four new factors and fifty-four sub-factors. Additionally, this paper developed a relationship model of factors. The results could be used in future work to explore and validate more evaluation factors by using data mining

    Slimmable Generative Adversarial Networks

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    Generative adversarial networks (GANs) have achieved remarkable progress in recent years, but the continuously growing scale of models makes them challenging to deploy widely in practical applications. In particular, for real-time generation tasks, different devices require generators of different sizes due to varying computing power. In this paper, we introduce slimmable GANs (SlimGANs), which can flexibly switch the width of the generator to accommodate various quality-efficiency trade-offs at runtime. Specifically, we leverage multiple discriminators that share partial parameters to train the slimmable generator. To facilitate the \textit{consistency} between generators of different widths, we present a stepwise inplace distillation technique that encourages narrow generators to learn from wide ones. As for class-conditional generation, we propose a sliceable conditional batch normalization that incorporates the label information into different widths. Our methods are validated, both quantitatively and qualitatively, by extensive experiments and a detailed ablation study.Comment: Accepted to AAAI 202

    Clinicopathologic Evaluation of Prognostic Factors for Squamous Cell Carcinoma of the Buccal Mucosa

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    BackgroundThe purpose of this research was to evaluate the prognostic significance of clinicopathologic variables on the survival rate for squamous cell carcinoma of the buccal mucosa (BMSCC). We analyzed the outcomes of surgical therapy for this aggressive cancer and compared these results with those in the literature.MethodsWe reviewed the medical charts of 172 patients treated in our institution between 1990 and 2005. There were 22 patients excluded from our studies: 20 patients with advanced tumors who received no treatment or palliative treatment, and 2 patients who had received preoperative radiotherapy (RT). The remaining 150 patients were treated with surgeries and among them, 56 patients had undergone postoperative RT. The influence of clinicopathologic factors on the survival rate was analyzed with the Kaplan-Meier method and log-rank test. Multivariate analysis was assessed with Cox's regression model.ResultsThere were 148 males and 2 females, with a mean age of 53.5 years. The prevalence rate of habitual betel quid chewing documented in charts among 113 patients was 75%. The 5-year overall survival rate and disease-specific survival rate for all patients were 64% and 69%, respectively. For patients with stages I, II, III, and IV disease, the 5-year disease-specific survival rates were 90%, 77%, 52%, and 47%, respectively (p< 0.001). According to the multivariate analysis, the pathologic staging and histologic grading of the tumor were independently the important prognostic factors affecting survival rate. There were 80 patients who developed locoregional recurrence in lymph nodes in the follow-up diagnoses. Distant metastases occurred in 14 patients, with 11 of them also having locoregional recurrence. The distant metastases were found in the lungs (8/14), T-spine (3/14), liver (2/14) and brain (1/14).ConclusionPathologic stage and histologic grade are the most important prognostic factors

    Search for new physics from BπϕB\to\pi \phi

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    We investigate the pure penguin process BπϕB^-\to \pi^-\phi using QCD factorization approach to calculate hadronic matrix elements to the αs\alpha_s order in some well-known NP models. It is shown that the NP contributions in R-parity conserved SUSY models and 2HDMs are not enough to saturate the experimental upper bounds for BϕπB\to \phi \pi. We have shown that the flavor changing ZZ^\prime models can make the branching ratios of BϕπB\to \phi \pi to saturate the bound under all relevant experimental constraints.Comment: No figure
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