1,992 research outputs found

    Final state phases in B -> D\pi, \bar{D}\pi decays and CP-asymmetry

    Full text link
    Final state phases \delta_f and \delta_f' in B-> D pi, barD pi decays are shown to be equal i.e. \delta =\delta_f-\delta_f' = 0. Thus CP-violating asymmetry A(t) is independent of final state phases. The estimate for the phases \delta_f and \delta_f' is also given.Comment: 6 pages, no figur

    Yet another way to measure Îł\gamma

    Get PDF
    We show that the CKM phase 2ÎČ+Îł2 \beta+\gamma can be extracted from measurement of the time dependent rates in the decays Bˉ0→D(∗)±M∓\bar{B}^0 \to D^{(*)\pm} M^\mp and B0→D(∗)±M∓B^0 \to D^{(*)\pm} M^\mp, where M=a0M=a_0, π(1300)\pi(1300), b1b_1, a2a_2, π2\pi_2, ρ3\rho_3. These channels have a large asymmetry between decays of Bˉ0\bar{B}^0 and B0B^0 into the same final state. Even though the branching ratios are small, their sensitivity to Îł\gamma can be competitive with decays into D(∗)D^{(*)} and (π,ρ,a1)(\pi,\rho,a_1).Comment: 5 pages, some clarifications and references adde

    Governance Issues in the Principal-Agent Framework: Producing Cellulosic Ethanol in Michigan

    Get PDF
    This article analyzes the incentives and compensation problems faced by cellulosic ethanol producer and logging firms and the consequent impact on the organization of the wood based cellulosic ethanol industry in the US. The success of this relationship is central to setting up the biofuel industry in Michigan and in the US at large. The theoretical results indicate that specification contract under the principal-agent framework is of limited utility due to’ metering’ problem when the principal contracts with multiple agents for the supply of feedstock.. Alternative arrangements including JVs have the potential to provide close to first best solutions.Principal-Agent, Cellulosic Ethanol, Michigan, Multiple agents, Asymmetric Information, Agribusiness, Institutional and Behavioral Economics, Resource /Energy Economics and Policy, D82, D86, L23, L24, Q42,

    CP violation and the CKM angle γ\gamma from angular distributions of untagged BsB_s decays governed by bˉ→cˉusˉ\bar b\to\bar c u\bar s

    Full text link
    We demonstrate that time-dependent studies of angular distributions for BsB_s decays caused by bˉ→cˉusˉ\bar b\to\bar cu\bar s quark-level transitions extract cleanly and model-independently the CKM angle γ\gamma. This CKM angle could be cleanly determined from untagged BsB_s decays alone, if the lifetime difference between the BsB_s mass eigenstates BsLB_s^L and BsHB_s^H is sizable. The time-dependences for the relevant tagged and untagged observables are given both in a general notation and in terms of linear polarization states and should exhibit large CP-violating effects. These observables may furthermore provide insights into the hadronization dynamics of the corresponding exclusive BsB_s decays thereby allowing tests of the factorization hypothesis.Comment: 14 pages, LaTeX, no figure

    Determination of the CP Violating Phase γ\gamma by a Sum Over Common Decay Modes to BsB_s and Bˉs\bar{B}_s

    Full text link
    To help the difficult determination of the angle Îł\gamma of the unitarity triangle, Aleksan, Dunietz and Kayser have proposed the modes of the type K−Ds+K^-D^+_s, common to BsB_s and Bˉs\bar{B}_s. We point out that it is possible to gain in statistics by a sum over all modes with ground state mesons in the final state, i.e. K−Ds+K^-D^+_s, K∗−D+sK^{*-}D_+^s, K−Ds∗+K^-D^{*+}_s, K∗−Ds∗+K^{*-}D^{*+}_s. The delicate point is the relative phase of these different contributions to the dilution factor DD of the time-dependent asymmetry. Each contribution to DD is proportional to a product FcbF^{cb} FubF^{ub} fDsf_{D_s} fKf_K where FF denotes form factors and ff decay constants. Within a definite phase convention, lattice calculations do not show any change in sign when extrapolating to light quarks the form factors and decay constants. Then, we can show that all modes contribute constructively to the dilution factor, except the PP-wave K∗−Ds∗+K^{*-}D^{*+}_s, which is small. Quark model arguments based on wave function overlaps also confirm this stability in sign. By summing over all these modes we find a gain of a factor 6 in statistics relatively to K−Ds+K^-D^+_s. The dilution factor for the sum DtotD_{tot} is remarkably stable for theoretical schemes that are not in very strong conflict with data on B→ψK(K∗)B \to \psi K(K^*) or extrapolated from semileptonic charm form factors, giving Dtot≄0.6D_{tot} \geq 0.6, always close to D(K−Ds+)D(K^- D^+_s).Comment: 22 pages, LPTHE Orsay 94/03, DAPNIA/SPP/94-2

    The Care Accelerator R&D Programme in Europe

    Get PDF
    CARE, an ambitious and coordinated programme of accelerator research and developments oriented towards high energy physics projects, has been launched in January 2004 by the main European laboratories and the European Commission. This project aims at improving existing infrastructures dedicated to future projects such as linear colliders, upgrades of hadron colliders and high intensity proton drivers. We describe the CARE R&D plans, mostly devoted to advancing the performance of the superconducting technology, both in the fields of RF cavities for electron or proton acceleration and of high field magnets, as well as to developing high intensity electron and proton injectors. We highlight some results and progress obtained so far

    b Physics Beyond the Standard Model

    Get PDF
    I review the signals for New Physics in CP-violating measurements in B and Lambda_b decays. I also discuss ways of identifying this New Physics, should such a signal be found.Comment: 10 pages, LaTeX, 1 figure, ps file included. References adde

    Phenomenological discussion of B→PVB\to P V decays in QCD improved factorization approach

    Full text link
    Trying a global fit of the experimental branching ratios and CP-asymmetries of the charmless B→PVB\to PV decays according to QCD factorization, we find it impossible to reach a satisfactory agreement, the confidence level (CL) of the best fit is smaller than .1 %. This failure reflects the difficulty to accommodate several large experimental branching ratios of the strange channels. Furthermore, experiment was not able to exclude a large direct CP asymmetry in Bˉ0→ρ+π−\bar {B}^0\to\rho^+ \pi^-, which is predicted very small by QCD factorization. Proposing a fit with QCD factorization complemented by a charming-penguin inspired model we reach a best fit which is not excluded by experiment (CL of about 8 %) but is not fully convincing. These negative results must be tempered by the remark that some of the experimental data used are recent and might still evolve significantly.Comment: 8 pages, 2 figures (requires epsfig, psfrag),talk presented at the XXXVIIIth Rencontres de Moriond: Electroweak Interactions and Unified Theories,Les Arcs, France, March 15-22, 2003. To be published in the Proceeding
    • 

    corecore