440 research outputs found

    Unravelling soft components in the shape function for inclusive B decays

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    In the heavy-quark limit, the decay spectrum for radiative and semileptonic inclusive B-meson decays is determined by a universal structure function, i.e. the shape function. We study the constraints on the bilocal heavy-quark operator for the shape function from the QCD equations of motion and heavy-quark symmetry, and we obtain a new basis of nonlocal operators that reveals relevant soft components in the shape function. Those nonlocal operators represent the ``kinetic energy distribution'' of the b-quark inside the B-meson and the four-parton correlations with additional quarks and gluons. A corresponding local operator basis relevant for relating the shape function to HQET parameters is also given, and novel effects of the quark-gluon correlations are discussed.Comment: 19 pages PTPTeX. Typos corrected and improvements made to the text. References added. Published versio

    Transverse double-spin asymmetries for small QTQ_T Drell-Yan pair production in pppp and ppˉp\bar{p} collisions

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    We discuss transverse double-spin asymmetries for dimuon production at small transverse-momentum QTQ_T in pppp and ppˉp\bar{p} collisions. All order resummation of large logarithms relevant in small QTQ_T region is performed at next-to-leading logarithmic (NLL) accuracy, and asymmetries at RHIC, J-PARC and GSI are calculated.Comment: 4 pages, 2 figures, Talk given at DIS06, April 20-24, 2006, Tsukuba, Japa

    An inverse system approach to Menger manifolds

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    AbstractWe define the concept of μk-defining spectrum and give alternative proofs of some results of Menger manifolds, including the Characterization Theorem

    A variant of the bipartite relation theorem and its application to clique graphs

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    We consider a homological variant of the Bipartite Relation Theorem (\cite{bjorner}) in the context of the flag complex of the square of a bipartite graph (\cite{lpvf}). We apply the results to study the homology and homotopy groups of the flag complexes of clique graphs
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