919 research outputs found

    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

    CP parameters of the B systems from Tevatron

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    Recent results on CP parameters of the B systems obtained by the CDF and D0 collaborations using the data samples collected at the Tevatron Collider in the period 2002 - 2007 were presented at the QCD 2008 conference (Montpellier, France). These results include measurements of the mixing phase, decay width difference, and CP violation parameters in the Bs and Bu decays.Comment: Presented at the QCD 2008 Conference (Montpellier, France); added references; corrected RCP+ paramete

    Isospin-breaking effects on alpha extracted in B --> pi pi, rho rho, rho pi

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    Isospin-breaking in B --> pi pi caused by pi^0-eta-eta' mixing is studied in a model-independent way using flavor SU(3). Measured branching ratios for B^+ --> pi^+ pi^0, B^+ --> pi^+ eta^(') and B^0 --> pi^0 eta^(') imply an uncertainty in alpha smaller than 1.4 degree. We find a negligible effect of pi^0-eta-eta' mixing on alpha in B --> rho pi. Characterizing the effect of rho^0-omega mixing in B --> rho rho and in B --> rho pi by the two-pion invariant mass dependence, we point out a way of constraining this effect experimentally or eliminating it altogether. We show that a model-independent shift in alpha caused by electroweak penguin amplitudes in B --> pi pi and B --> rho rho, \Delta alpha_{EWP}=1.5+- 0.3 degree, may be slightly different in B --> rho pi. Other sources of isospin-breaking in these processes are briefly discussed.Comment: 21 pages, very slight changes, same version as in Physical Review

    Time Vs. Goods: The Value of Measuring Household Production Technologies

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    We take U.S. and Israeli household data on expenditures of time and goods, generate an exhaustive set of commodities that households produce/consume using them, and calculate their relative goods intensities. Leisure activities are uniformly relatively time intensive, health, travel and lodging relatively goods intensive. We demonstrate how education and age alter the goods intensity of household production. The results of this accounting can be used as guides to: Understanding how goods and income taxation interact to affect welfare; expanding notions of the determinants of international flows of goods; generating models of business cycles and endogenous growth to include interactions of goods and time consumption; and obtaining better measures of the distribution of well being.

    The Demand for Variety: A Household Production Perspective

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    Product diversity pervades every modern marketplace, and economists have devoted substantial attention to firms' decisions about the supply of variety. This study looks at the consumer's side by discussing the demand for variety. Using the framework of the home-production model, we trace differences in demand to differences in the opportunity costs of various activities. The cost differences are associated with investments in human capital; and the resulting differences in schooling attainment produce differences in time costs that in turn alter the kinds and variety of activities in which household members engage. Using time-budget surveys from Australia, Israel, the Netherlands, Sweden, the United States and West Germany from between 1985 and 1994, we find substantial differences among households in the extent of variety in the nonwork activities that they produce. More educated individuals generate more variety, engaging in both additional activities and the same ones as the less educated, with most of the effect of education on the variety of nonroutine activities. There is more variety on weekends; women engage in more different activities than men; young children add to variety in household consumption/production, especially among women; and income effects are clearly positive.

    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 B0\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

    Ratios of heavy hadron semileptonic decay rates

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    Ratios of charmed meson and baryon semileptonic decay rates appear to be satisfactorily described by considering only the lowest-lying (S-wave) hadronic final states and assuming the kinematic factor describing phase space suppression is the same as that for free quarks. For example, the rate for DsD_s semileptonic decay is known to be (17.0±5.3)(17.0 \pm 5.3)% lower than those for D0D^0 or D+D^+, and the model accounts for this difference. When applied to hadrons containing bb quarks, this method implies that the BsB_s semileptonic decay rate is about 1% higher than that of the nonstrange BB mesons. This small difference thus suggests surprisingly good local quark-hadron duality for BB semileptonic decays, complementing the expectation based on inclusive quark-hadron duality that these differences in rates should not exceed a few tenths of a percent. For Λb\Lambda_b semileptonic decay, however, the inclusive rate is predicted to be about 13% greater than that of the nonstrange BB mesons. This value, representing a considerable departure from a calculation using a heavy quark expansion, is close to the corresponding experimental ratio Γ(Λb)/Γˉ(B)=1.13±0.03\Gamma(\Lambda_b)/ \bar \Gamma(B) = 1.13 \pm 0.03 of total decay rates.Comment: 12 pages, no figures. References 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

    P and CP violation in B physics

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    While the Kobayashi--Maskawa single phase origin of CP violation passed its first crucial precision test in BJ/ψKSB\to J/\psi K_S, the chirality of weak bb-quark couplings has not yet been carefully tested. We discuss recent proposals for studying the chiral and CP-violating structure of these couplings in radiative and in hadronic B decays.Comment: 15 pages, talk at PASCOS'03, Tata Inst., Mumbai, Jan. 200

    Charmless BPPB \to PP decays using flavor SU(3) symmetry

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    The decays of BB mesons to a pair of charmless pseudoscalar (PP) mesons are analyzed within a framework of flavor SU(3). Symmetry breaking is taken into account in tree (TT) amplitudes through ratios of decay constants; exact SU(3) is assumed elsewhere. Acceptable fits to BππB \to \pi \pi and BKπB \to K \pi branching ratios and CP asymmetries are obtained with tree, color-suppressed (CC), penguin (PP), and electroweak penguin (PEWP_{EW}) amplitudes. Crucial additional terms for describing processes involving η\eta and η\eta' include a large flavor-singlet penguin amplitude (SS) as proposed earlier and a penguin amplitude PtuP_{tu} associated with intermediate tt and uu quarks. For the B+π+ηB^+ \to \pi^+ \eta' mode a term StuS_{tu} associated with intermediate tt and uu quarks also may be needed. Values of the weak phase γ\gamma are obtained consistent with an earlier analysis of BVPB \to VP decays, where VV denotes a vector meson, and with other analyses of CKM parameters.Comment: 26 pages, 1 figure. To be submitted to Phys. Rev. D. Reference update
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