1,148 research outputs found

    Isospin Considerations in Correlations of Pions and BB mesons

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    The correlations between a BB meson and a pion produced nearby in phase space should respect isospin reflection symmetry I3→−I3I_3 \to -I_3. Thus, one generally expects similar π+B0\pi^+ B^0 and π−B+\pi^- B^+ correlations (non-exotic channels), and similar π−B0\pi^- B^0 and π+B+\pi^+ B^+ correlations (exotic channels). Exceptions include (a) fragmentation processes involving exchange of quarks with the producing system, (b) misidentification of charged kaons as charged pions, and (c) effects of decay products of the associated B‾\overline{B}. All of these can affect the apparent signal for correlations of charged BB mesons with charged hadrons. The identification of the flavor of neutral BB mesons through the decay B0→K∗0J/ψB^0 \to K^{*0} J/\psi requires good particle identification in order that the decay K∗0→K+π−K^{*0} \to K^+ \pi^- not be mistaken for K‾∗0→K−π+\overline{K}^{*0} \to K^- \pi^+, in which case the correlations of neutral BB mesons with hadrons can be underestimated.Comment: LaTeX EPSF file; 8 uuencoded figures to be submitted separatel

    What can we learn from phi_1 and B_d^0 -> pi^+ pi^- ?

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    We discuss what we can understand from ϕ1\phi_1 and Bd0→π+π−B^0_d\to \pi^+ \pi^- decay mode. Using a convention without weak phases ϕ2\phi_2 and ϕ3\phi_3, we can solve the parameters from the time-depended CP asymmetry. If we can put a condition the contribution from penguin except for the CKM factor including in the diagram is small, then we can lead the allowed region of RtR_t or ϕ2\phi_2 by using the convention.Comment: 7 pages, 4 figures, references and comments adde

    SU(3) Decomposition of Two-Body B Decay Amplitudes

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    We present the complete flavor SU(3) decomposition of decay amplitudes for decays of the triplet (B^+_u, B^0_d, B^0_s) of B mesons nonleptonically into two pseudoscalar mesons. This analysis holds for arbitrarily broken SU(3) and can be used to generate amplitude relations when physical arguments permit one to neglect or relate any of the reduced amplitudes.Comment: 31 pages, revtex, no figure

    A Possibility of large electro-weak penguin contribution in B -> K pi modes

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    We discuss about a possibility of large electro-weak penguin contribution in B -> K pi from recent experimental data. The several relations among the branching ratios which realize when the contributions from tree type and electro-weak penguin are small compared with the gluon penguin and can be treated as the expansion parameters do not satisfy the data. The difference comes from the r^2 terms which is the square of the ratio with the gluon penguin and the main contribution comes from electro-weak penguin. We find that the contribution from electro-weak penguin may be large to explain the experimental data. If the magnitude estimated from experiment is quite large compared with the theoretical estimation, then it may be including some new physics effects.Comment: 11 pages, 1 figure, Typos correcte

    Framework for Identification of Neutral B Mesons

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    We introduce a method for the study of CP-violating asymmetries in tagged states of neutral BB mesons with arbitrary coherence properties. A set of time-dependent measurements is identified which completely specifies the density matrix of the initial state in a two-component space with basis vectors B0B^0 and B‾0\overline B^0, and permits a determination of phases in the Cabibbo-Kobayashi-Maskawa matrix. For a given tagging configuration, the measurement of decays both to flavor eigenstates and to CP eigenstates provides the necessary information.Comment: Submitted to Phys. Rev. Letters. 8 pages, LaTeX, Technion-PH-93-31 / EFI 93-3

    Mesino - Antimesino Oscillations

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    The phenomenological implications of supersymmetric theories with low scale supersymmetry breaking and a squark as the lightest standard model superpartner are investigated. Such squarks hadronize with light quarks, forming sbaryons and mesinos before decaying. Production of these supersymmetric bound states at a high energy collider can lead to displaced jets with large negative impact parameter. Neutral mesino - antimesino oscillations are not forbidden by any symmetry and can occur at observable rates with distinctive signatures. Stop mesino - antimesino oscillations would give a sensitive probe of up-type sflavor violation in the squark sector, and can provide a discovery channel for supersymmetry through events with a same-sign top-top topology.Comment: 4 pages, 1 figure, LaTe

    Strong and Weak Phases from Time-Dependent Measurements of B→ππB \to \pi \pi

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    Time-dependence in B0(t)→π+π−B^0(t) \to \pi^+ \pi^- and \ob(t) \to \pi^+ \pi^- is utilized to obtain a maximal set of information on strong and weak phases. One can thereby check theoretical predictions of a small strong phase δ\delta between penguin and tree amplitudes. A discrete ambiguity between δ≃0\delta \simeq 0 and δ≃π\delta \simeq \pi may be resolved by comparing the observed charge-averaged branching ratio predicted for the tree amplitude alone, using measurements of B→πlνB \to \pi l \nu and factorization, or by direct comparison of parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix with those determined by other means. It is found that with 150 fb−1^{-1} from BaBar and Belle, this ambiguity will be resolvable if no direct CP violation is found. In the presence of direct CP violation, the discrete ambiguity between δ\delta and π−δ\pi - \delta becomes less important, vanishing altogether as ∣δ∣→π/2|\delta| \to \pi/2. The role of measurements involving the lifetime difference between neutral BB eigenstates is mentioned briefly.Comment: 14 pages, LaTeX, 5 figures, to be published in Phys. Rev. D. Updated version with one reference change

    Weak Coupling Phase from Decays of Charged B Mesons to πK\pi K and ππ\pi\pi

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    The theory of CPCP violation based on phases in weak couplings in the Cabibbo-Kobayashi-Maskawa (CKM) matrix requires the phase γ≡Arg Vub∗\gamma \equiv {\rm Arg~} V^*_{ub} (in a standard convention) to be nonzero. A measurement of γ\gamma is proposed based on charged BB meson decay rates to π+K0\pi^+ K^0, π0K+\pi^0 K^+, π+π0\pi^+ \pi^0, and the charge-conjugate states. The corresponding branching ratios are expected to be of the order of 10−510^{-5}. (submitted to Physical Review Letters)Comment: LaTeX, 8 pages, 2 figures (not included, available upon request), TECHNION-PH-94-7, EFI-94-14, UdeM-LPN-TH-94-19
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