25 research outputs found

    Nonleptonic Cabibbo Favoured BB-Decays and CPCP-Asymmetries for Charmed Final Hadron States in Isgur and Wise Theory

    Full text link
    The Cabibbo allowed non-leptonic BB-decays in two hadrons are studied, within the factorization hypothesis, in the framework of Isgur and Wise theory for the matrix elements of the ΔB=ΔC=±1\Delta B=-\Delta C=\pm 1 weak currents. The SU(2)HFSU(2)_{HF} symmetry relates ΔB=1|\Delta B|=1 to ΔC=1|\Delta C|=1 currents, which have been measured in the semileptonic strange decays of charmed particles. By assuming colour screening and allowing for SU(3)SU(3) invariant contributions from the annihilation terms with charmed final states one is able to comply with the present experimental knowledge.\\ The CPCP violating asymmetries in neutral BB decays are given for charmed final states in terms of the KMK-M angles. With the central values found for the annihilation parameters there is a destructive (constructive) interference between the direct and annihilation terms in the Cabibbo allowed (doubly forbidden) amplitudes for the decays into D0(D0)π0D^{0}(D^{*0})\pi^0 and D0ρ0D^0\rho^0 so that they may be of the same order. This would imply large asymmetries, for which however our present knowledge on the amplitudes does not allow to predict even their sign.\\ We have better confidence in our predictions for the charged final states than the neutral ones and can draw the conclusion that the detection of the corresponding asymmetries requires, at least, 10610^6 tagged neutral BB-particles.Comment: CERNTEX, 17 pages, DSF-92/23, INFN-NA-IV-92/2

    Optimized Variables of the Study of Λb\Lambda_b Polarization

    Full text link
    The value of the bb-baryon polarization can be extracted from inclusive data at LEP with better than 10\% precision based on current statistics. We present a new variable by which to measure the polarization, which is the ratio of the average electron energy to the average neutrino energy. This variable is both sensitive to polarization and insensitive to fragmentation uncertainties.Comment: 10 pages (LaTeX), 2 figures, MIT-CTP-2270, CERN-PPE/94-0
    corecore