| Higher Twist Distribution Amplitudes of Vector Mesons in QCD: Twist-4 Distributions and Meson Mass Corrections (1998) | |||||||||||||||
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| We present a systematic study of twist-4 light-cone distribution amplitudes of vector mesons in QCD, which is based on conformal expansion. The structure of meson mass corrections is studied in detail. A complete set of distribution amplitudes is constructed, which satisfies all (exact) equations of motion and constraints from conformal expansion. Nonperturbative input parameters are estimated from QCD sum rules. Our study suggests that meson mass corrections may present a dominant source of higher twist effects in exclusive processes. Submitted to Nuclear Physics B E-mail: Patricia.Ball@cern.ch y E-mail: vbraun@nordita.dk 1 Introduction The notion of distribution amplitudes refers to momentum fraction distributions of partons in a meson, in a particular Fock state, with a fixed number of constituents. For the minimal number of constituents, the distribution amplitude OE is related to the meson's Bethe-Salpeter wave function OE BS by OE(x) ¸ Z jk ? j!¯ d 2 k? OE BS (x; k? )... | |||||||||||||||
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