440 research outputs found
Unravelling soft components in the shape function for inclusive B decays
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 Drell-Yan pair production in and collisions
We discuss transverse double-spin asymmetries for dimuon production at small
transverse-momentum in and collisions. All order
resummation of large logarithms relevant in small 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
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
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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