33,868 research outputs found

    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

    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 B→ππ,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 B→ππB\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.

    Holographic QCD with Topologically Charged Domain-Wall/Membranes

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    We study the thermodynamical phase structures of holographic QCD with nontrivial topologically charged domain-wall/membranes which are originally related to the multiple θ\theta-vacua in the large NcN_c limit. We realize the topologically charged membranes as the holographic D6-brane fluxes in the Sakai-Sugimoto model. The D6-brane fluxes couple to the probe D8-anti-D8 via Chern-Simon term, and act as the source for the baryonic current density of QCD. We find rich phase structures of the dual meson system by varying asymptotic separation of D8 and anti-D8. Especially, there can be a thermodynamically favored and stable phase of finite baryonic current density. This provides the supporting evidence for the discovery of the topologically charged membranes found in the lattice QCD calculations. We also find a crossover phase with the limiting baryonic current density and temperature which suggest a Hagedorn-like phase transition of meson dissociation.Comment: 23 pages, 19 figures;v2 typos corrected;v3 text improve
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