13,967 research outputs found

    Direct CP violation in D+→K0(Kˉ0)π+D^+ \to K^0(\bar K^0) \pi^+ decays as a probe for new physics

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    In this paper we investigate CP violation in charged decays of DD meson. Particularly, we study the direct CP asymmetry of the Cabibbo favored non-leptonic D+→Kˉ0π+D^+ \rightarrow \bar K^0 \pi^+ and the doubly Cabibbo-suppressed decay mode D+→K0π+D^+ \rightarrow K^0 \pi^+ within standard model, two Higgs doublet model with generic Yukawa structure and left right symmetric models. In the standard model, we first derive the contributions from box and di-penguin diagrams contributing to their amplitudes which are relevant to the generation of the weak phases essential for non-vanishing direct CP violation. Then, we show that these phases are so tiny leading to a direct CP asymmetry of order 10−1110^{-11} in both decay modes. Regarding the two Higgs doublet model with generic Yukawa structure and after taking into account all constraints on the parameter space of the model, we show that the enhanced direct CP asymmetries can be 6 and 7 orders of magnitudes larger than the standard model prediction for D+→Kˉ0π+D^+ \rightarrow \bar K^0 \pi^+ and D+→K0π+D^+ \rightarrow K^0 \pi^+ respectively. Finally, within left right symmetric models, we find that sizable direct CP asymmetry of O(10−3){\mathcal O } (10^{-3}) can be obtained for the decay mode D+→Kˉ0π+D^+ \rightarrow \bar K^0 \pi^+ after respecting all relevant constraints.Comment: 20 pages, 2 figures. arXiv admin note: text overlap with arXiv:1710.0041

    One model, two languages: training bilingual parsers with harmonized treebanks

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    We introduce an approach to train lexicalized parsers using bilingual corpora obtained by merging harmonized treebanks of different languages, producing parsers that can analyze sentences in either of the learned languages, or even sentences that mix both. We test the approach on the Universal Dependency Treebanks, training with MaltParser and MaltOptimizer. The results show that these bilingual parsers are more than competitive, as most combinations not only preserve accuracy, but some even achieve significant improvements over the corresponding monolingual parsers. Preliminary experiments also show the approach to be promising on texts with code-switching and when more languages are added.Comment: 7 pages, 4 tables, 1 figur
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