9,559 research outputs found

    Chromosome mapping: radiation hybrid data and stochastic spin models

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    This work approaches human chromosome mapping by developing algorithms for ordering markers associated with radiation hybrid data. Motivated by recent work of Boehnke et al. [1], we formulate the ordering problem by developing stochastic spin models to search for minimum-break marker configurations. As a particular application, the methods developed are applied to 14 human chromosome-21 markers tested by Cox et al. [2]. The methods generate configurations consistent with the best found by others. Additionally, we find that the set of low-lying configurations is described by a Markov-like ordering probability distribution. The distribution displays cluster correlations reflecting closely linked loci.Comment: 26 Pages, uuencoded LaTex, Submitted to Phys. Rev. E, [email protected], [email protected]

    More on Symmetries in Heavy Quark Effective Theory

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    We present a general classification of all normal and ``chiral" symmetries of heavy quark effective theories. Some peculiarities and conondrums associated with the ``chiral" symmetries are discussed.Comment: 15 pages, preprint UR-1320, ER40685-77

    Higher Order 1/m1/m Corrections at Zero Recoil

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    The general structure of the 1/m1/m corrections at zero recoil is studied. The relevant matrix elements are forward matrix elements of local higher dimensional operators and their time ordered products with higher order terms from the Lagrangian. These matrix elements may be classified in a simple way and the analysis at the non recoil point for the form factor of heavy quark currents simplifies drastically. The second order recoil corrections to the form factor hA1h_{A1} of the axial vector current, relevant for the ∣Vcb∣|V_{cb}| determination from B→D∗B \to D^* decays, are estimated to be −5%<hA1−1<0-5\% < h_{A1} - 1 < 0.Comment: LaTeX, 25 pages, one figure, appended after \end{document} as uu-encoded and compressed eps file, uses epsf, CERN-TH.7162/9

    Excited Heavy Mesons Beyond Leading Order in the Heavy Quark Expansion

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    We examine the decays of excited heavy mesons, including the leading power corrections to the heavy quark limit. We find a new and natural explanation for the large deviation of the width of the D1(2420)D_1(2420) from the heavy quark symmetry prediction. Our formalism leads to detailed predictions for the properties of the excited bottom mesons, some of which recently have been observed. Finally, we present a detailed analysis of the effect of power corrections and finite meson widths on the angular distributions which may be measured in heavy meson decays.Comment: Uses REVTeX, 19 pages, 6 EPS figures embedded with epsf.st

    Phenomenological Study of Strong Decays of Heavy Hadrons in Heavy Quark Effective Theory

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    The application of the tensor formalism of the heavy quark effective theory (HQET) at leading order to strong decays of heavy hadrons is presented. Comparisons between experimental and theoretical predictions of ratios of decay rates for B mesons, D mesons and kaons are given. The application of HQET to strange mesons presents some encouraging results. The spin-flavor symmetry is used to predict some decay rates that have not yet been measured.Comment: 10 page

    Second Order Power Corrections in the Heavy Quark Effective Theory I. Formalism and Meson Form Factors

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    In the heavy quark effective theory, hadronic matrix elements of currents between two hadrons containing a heavy quark are expanded in inverse powers of the heavy quark masses, with coefficients that are functions of the kinematic variable v⋅v′v\cdot v'. For the ground state pseudoscalar and vector mesons, this expansion is constructed at order 1/mQ21/m_Q^2. A minimal set of universal form factors is defined in terms of matrix elements of higher dimension operators in the effective theory. The zero recoil normalization conditions following from vector current conservation are derived. Several phenomenological applications of the general results are discussed in detail. It is argued that at zero recoil the semileptonic decay rates for B→D ℓ νB\to D\,\ell\,\nu and B→D∗ℓ νB\to D^*\ell\,\nu receive only small second order corrections, which are unlikely to exceed the level of a few percent. This supports the usefulness of the heavy quark expansion for a reliable determination of VcbV_{cb}.Comment: (34 pages, REVTEX, two postscript figures available upon request), SLAC-PUB-589
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