219 research outputs found
Chiral Perturbation Theory
Full text linkThe basic ideas and power counting rules of chiral perturbation theory are
discussed. The formalism of velocity dependent fields for baryons, and for
hadrons containing a heavy quark, is explained. (Invited Talk, 1993 QCD
Rencontres de Moriond)Comment: (uses harvmac, 9 pages, 1 figure), UCSD/PTH 93-1
Deep inelastic scattering as x -> 1 using soft-collinear effective theory
Full text linkSoft-collinear effective theory (SCET) is used to sum Sudakov
double-logarithms in the x ->1 endpoint region for the deep inelastic
scattering structure function. The calculations are done in both the target
rest frame and the Breit frame. The separation of scales in the effective
theory implies that the anomalous dimension of the SCET current is linear in ln
mu, and the anomalous dimension for the Nth moment of the structure function is
linear in ln N, to all orders in perturbation theory. The SCET formulation is
shown to be free of Landau pole singularities. Some important differences
between the deep inelastic structure function and the shape function in B decay
are discussed.Comment: 19 pages, minor typos fixed, and a comment added on the longitudinal
structure functio
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