758 research outputs found

    CP Tagged Decays at SuperBaBar

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    We explore the possibility of measuring the CKM parameter gamma using CP tagged decays at a very high luminosity e+e- B Factory. A new collider capable of integrating as much as 10 inverse attobarns per year is being discussed as a possible future for SLAC beyond the current PEP-II program, and could also be in the future of KEK. In two years of operation, it could be possible for a successor to BaBar or Belle to accumulate a sample of one million CP tagged B decays. We find that a theoretically clean extraction of gamma with uncertainty less than 5 degrees may be achievable in the analysis of such a data set.Comment: 14 pages, 4 figures; minimal revisions for version to appear in Physical Review D, all formulas and conclusions unchange

    Surface plasmon resonance under conditions of electromagnetically induced transparency

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    A scheme for a surface plasmon resonance system under conditions of electromagnetically induced transparency (EIT) is proposed. The system is composed of three layers: a prism, a thin metal film, and a hybrid dielectric consisting of EIT atoms and a background substance. A probe and a coupling laser beam are input. Corresponding analytical formulas are derived for the cases when one or both of the laser beams excite surface plasmon polaritons at the metal/dielectric interface. Under resonance conditions, an extremely sharp dip appears in the reflectivity-frequency spectrum of the probe field, revealing new properties of two-dimensional EIT. The reflectivity is extremely sensitive to shifts in the laser frequencies and atomic levels, and to variations of permittivity of the substrate. This EIT-SPR system may to be used for novel magnetometers and biosensors

    Getting beta-alpha without penguins

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    Oscillation effects in B0 -> Ks D0 and related processes are considered to determine delta=beta-alpha+pi. We suggest that D0 decays to CP eigenstates used in concert with inclusive D0 decays provide a powerful method for determining delta cleanly i.e. without any complication from penguin processes. The CP asymmetry is expected to be <=40% for D0 decays to non-CP eigenstates and <=80% for decays to CP eigenstates. This method can lead to a fairly accurate determination of delta with O(10^8-10^9) B-mesons.Comment: 4 pages 1 figure; Version 2: minor changes; references added; Some changes in response to Referee Comment

    Quantum subgroups of the Haagerup fusion categories

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    We answer three related questions concerning the Haagerup subfactor and its even parts, the Haagerup fusion categories. Namely we find all simple module categories over each of the Haagerup fusion categories (in other words, we find the `"quantum subgroups" in the sense of Ocneanu), we find all subfactors whose principal even part is one of the Haagerup fusion categories, and we compute the Brauer-Picard groupoid of Morita equivalences of the Haagerup fusion categories. In addition to the two even parts of the Haagerup subfactor, there is exactly one more fusion category which is Morita equivalent to each of them. This third fusion category has six simple objects and the same fusion rules as one of the even parts of the Haagerup subfactor, but has not previously appeared in the literature. We also find the full lattice of intermediate subfactors for every subfactor whose even part is one of these three fusion categories, and we discuss how our results generalize to Izumi subfactors.Comment: Final version. 40 pages, many figure

    Possibility of extracting the weak phase γ\gamma from ΛbΛD0\Lambda_b \to \Lambda D^0 decays

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    We explore the possibility of extracting the weak phase γ\gamma from pure tree decays ΛbΛ(D0,D0ˉ,DCP0)\Lambda_b \to \Lambda (D^0, \bar{D^0}, D^0_{CP}) in a model independent way. The CP violating weak phase γ\gamma can be determined cleanly, without any hadronic uncertainties, as these decay modes are free from the penguin pollutions. Furthermore, neither tagging nor time dependent studies are required to extract the angle γ\gamma with these modes.Comment: 12 pages, LaTex, Minor changes in the text, version to appear in Phys. Rev.

    Stability of Spatial Optical Solitons

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    We present a brief overview of the basic concepts of the soliton stability theory and discuss some characteristic examples of the instability-induced soliton dynamics, in application to spatial optical solitons described by the NLS-type nonlinear models and their generalizations. In particular, we demonstrate that the soliton internal modes are responsible for the appearance of the soliton instability, and outline an analytical approach based on a multi-scale asymptotic technique that allows to analyze the soliton dynamics near the marginal stability point. We also discuss some results of the rigorous linear stability analysis of fundamental solitary waves and nonlinear impurity modes. Finally, we demonstrate that multi-hump vector solitary waves may become stable in some nonlinear models, and discuss the examples of stable (1+1)-dimensional composite solitons and (2+1)-dimensional dipole-mode solitons in a model of two incoherently interacting optical beams.Comment: 34 pages, 9 figures; to be published in: "Spatial Optical Solitons", Eds. W. Torruellas and S. Trillo (Springer, New York

    Exploring Flavor Structure of Supersymmetry Breaking at B factories

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    We investigate quark flavor signals in three different supersymmetric models, the minimal supergravity, the SU(5) SUSY GUT with right handed neutrinos, and the minimal supersymmetric standard model with U(2) flavor symmetry, in order to study physics potential of the present and future BB factories. We evaluate CP asymmetries in various B decay modes, ΔmBs\Delta m_{B_s}, ΔmBd\Delta m_{B_d}, and ϵK\epsilon_K. The allowed regions of the CP asymmetry in BJ/ψKSB\to J/\psi K_S and ΔmBs/ΔmBd\Delta m_{B_s}/\Delta m_{B_d} are different for the three models so that precise determinations of these observables in near future experiments are useful to distinguish the three models. We also investigate possible deviations from the standard model predictions of CP asymmetries in other B decay modes. In particular, a large deviation is possible for the U(2) model. The consistency check of the unitarity triangle including Bππ,ρπ,D()K(),D()π,DρB\to \pi\pi,\rho\pi,D^{(*)}K^{(*)},D^{(*)}\pi,D^{*}\rho, and so on, at future high luminosity e+ee^+e^- BB factories and hadronic BB experiments is therefore important to distinguish flavor structures of different supersymmetric models.Comment: revtex4, 31 pages, 7 figure

    Rescattering and chiral dynamics in B\to \rho\pi decay

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    We examine the role of B^0(\bar B^0) \to \sigma \pi^0 \to \pi^+\pi^- \pi^0 decay in the Dalitz plot analysis of B^0 (\bar B^0) \to \rho\pi \to \pi^+\pi^-\pi^0 decays, employed to extract the CKM parameter \alpha. The \sigma \pi channel is significant because it can break the relationship between the penguin contributions in B\to\rho^0\pi^0, B\to\rho^+\pi^-, and B\to\rho^-\pi^+ decays consequent to an assumption of isospin symmetry. Its presence thus mimics the effect of isospin violation. The \sigma\pi^0 state is of definite CP, however; we demonstrate that the B\to\rho\pi analysis can be generalized to include this channel without difficulty. The \sigma or f_0(400-1200) ``meson'' is a broad I=J=0 enhancement driven by strong \pi\pi rescattering; a suitable scalar form factor is constrained by the chiral dynamics of low-energy hadron-hadron interactions - it is rather different from the relativistic Breit-Wigner form adopted in earlier B\to\sigma\pi and D\to\sigma\pi analyses. We show that the use of this scalar form factor leads to an improved theoretical understanding of the measured ratio Br(\bar B^0 \to \rho^\mp \pi^\pm) / Br(B^-\to \rho^0 \pi^-).Comment: 26 pages, 8 figs, published version. typos fixed, minor change

    Determining the Phases alpha and gamma from Direct CP Violation in B_u, B_d and B_s Decays to Two Vectors

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    A method for clean determination of the unitarity angles alpha and gamma is proposed that uses only direct CP violation and does not require any time dependent measurements. The method takes advantage of helicity amplitudes for B_u, B_d and B_s decay to two vector mesons and can be used, at any B-facility, in conjunction with a large number of modes. It also allows for experimental tests of theoretical approximations involved.Comment: 12 pages, no figure
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