Abstract
We study the twist-3 distribution amplitudes for scalar mesons made up of two valence quarks based on QCD sum rules. By choosing the proper correlation functions, we derive the moments of the scalar mesons up to the first two orders. Making use of these moments, we then calculate the first two Gegenbauer coefficients for twist-3 distribution amplitudes of scalar mesons. It is found that the second Gegenbauer coefficients of scalar density twist-3 distribution amplitudes for and mesons are quite close to that for , which indicates that the SU(3) symmetry breaking effect is tiny here. However, this effect could not be neglected for the forth Gegenbauer coefficients of scalar twist-3 distribution amplitudes between and . Besides, we also observe that the first two Gegenbauer coefficients corresponding to the tensor current twist-3 distribution amplitudes for all the , and are very small. The renormalization group evolution of condensates, quark masses, decay constants and moments are considered in our calculations. As a by-product, it is found that the masses for isospin , scalar mesons are around and respectively, while the mass for isospin state composed of is .
- Received 30 December 2006
DOI:https://doi.org/10.1103/PhysRevD.75.056001
©2007 American Physical Society