14,947 research outputs found

    The neutral top-pion and the lepton flavor violating ZZ decays ZliljZ\to l_{i}l_{j}

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    Taking into account the constraints of the present experimental limit of the process μeγ\mu\to e\gamma on the free parameters of topcolor-assisted technicolor(TC2) models, we calculate the contributions of the neutral top-pion to the lepton flavor violating(LFV) ZZ decays ZliljZ\to l_{i}l_{j}. Our results show that the value of the branching ratio Br(Zτl)Br(Z\to \tau l) is larger than that of Br(Zμe)Br(Z\to \mu e) in all of the parameter space and there is Br(Zτμ)Br(Zτe)2×1014Br(Z\to \tau\mu)\approx Br(Z\to \tau e)\simeq 2\times 10^{-14} , which is far from the reach of present or future experiments.Comment: 12 pages and 3 figures. To be published in J. Phys.

    Implications from recent measurements on sin 2\beta and muon g-2

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    The recent data on CP asymmetry in B>J/ΨKSB->J/\Psi K_S and muon g-2 are discussed in the framework of standard model and beyond. Possible new phase effects besides the CKM phase are discussed in the processes concerning CP violation in B decays and muon anomalous magnetic moment (muon g-2). It is found that the new phases will result in difference between angles betabeta measured from B>J/ΨKSB->J/\Psi K_S and the one from global fit. The ration between them serves as a probe of not only new physics but also new phase besides the CKM phase In the case of muon g-2, the new phase may change the interferences between various contributions. By including the new phases, some cancelations in the real coupling cases can be avoided and the large value of muon g-2 observed in the recent measurements can be understood.Comment: 7 pages, no figure. Talk delivered by Y.F.Zhou at International Conference on Flavor Physics (ICFP2001), May 31-June.6, at Zhang-Jia-Jie, Chin

    Object-based 2D-to-3D video conversion for effective stereoscopic content generation in 3D-TV applications

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    Three-dimensional television (3D-TV) has gained increasing popularity in the broadcasting domain, as it enables enhanced viewing experiences in comparison to conventional two-dimensional (2D) TV. However, its application has been constrained due to the lack of essential contents, i.e., stereoscopic videos. To alleviate such content shortage, an economical and practical solution is to reuse the huge media resources that are available in monoscopic 2D and convert them to stereoscopic 3D. Although stereoscopic video can be generated from monoscopic sequences using depth measurements extracted from cues like focus blur, motion and size, the quality of the resulting video may be poor as such measurements are usually arbitrarily defined and appear inconsistent with the real scenes. To help solve this problem, a novel method for object-based stereoscopic video generation is proposed which features i) optical-flow based occlusion reasoning in determining depth ordinal, ii) object segmentation using improved region-growing from masks of determined depth layers, and iii) a hybrid depth estimation scheme using content-based matching (inside a small library of true stereo image pairs) and depth-ordinal based regularization. Comprehensive experiments have validated the effectiveness of our proposed 2D-to-3D conversion method in generating stereoscopic videos of consistent depth measurements for 3D-TV applications

    Isospin relation and SU(3) breaking effects of strong phases in Charmless B decays

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    Isospin and flavor SU(3) relations in charmless hadronic B decays Bππ,πKB\to \pi \pi, \pi K are investigated in detail with paying attention to the SU(3) symmetry breaking effects in both amplitudes and strong phases. In general, the isospin and the flavor SU(3) structure of the effective Hamiltonian provide several relations among the amplitudes and strong phases. Whereas a global fit to the latest data shows that some relation seems not to be favorable for a consistent explanation to the current data within the standard model (SM). By considering several patterns of SU(3) breaking, the amplitudes and the corresponding strong phases are extracted and compared with the theoretical estimations. It is found that in the case of SU(3) limits and also the case with SU(3) breaking only in amplitudes, the fitting results lead to an unexpected large ratio between two isospin amplitudes a3/2c/a3/2ua^{c}_{3/2}/a^{u}_{3/2}, which is about an order of magnitude larger than the SM prediction. The results are found to be insensitive to the weak phase γ\gamma. By including SU(3) breaking effects on the strong phases, one is able to obtain a consistent fit to the current data within the SM, which implies that the SU(3) breaking effect on strong phases may play an important role in understanding the observed charmless hadronic B decay modes BππB\to \pi \pi and πK\pi K. It is possible to test those breaking effects in the near future from more precise measurements of direct CP violation in B factories.Comment: 14 pages, revtex4, no figure, references added. Updated to the latest data. To appear in Euro. Phys. Journ.