منابع مشابه
The Fubini-Furlan-Rossetti Sum Rule Revisited
The Fubini-Furlan-Rossetti sum rule for pion photoproduction on the nucleon is evaluated by dispersion relations at constant t, and the corrections to the sum rule due to the finite pion mass are calculated. Near threshold these corrections turn out to be large due to pion-loop effects, whereas the sum rule value is closely approached if the dispersion integrals are evaluated for sub-threshold ...
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متن کاملQCD Sum Rule Analysis
We present a QCD sum rule calculation of the spin-symmetry violating universal function χ2(v · v′), which appears at order 1/mQ in the heavy quark expansion of meson form factors. This function vanishes in the standard approximation, where radiative effects are neglected. For the first time, the complete set of diagrams arising at order αs is evaluated. In particular, we find χ2(1) = −(3.8± 0.4...
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ژورنال
عنوان ژورنال: Physical Review Special Topics - Accelerators and Beams
سال: 2010
ISSN: 1098-4402
DOI: 10.1103/physrevstab.13.024901