Study The Distribution Amplitude Of D Meson Under The QCD Sum Rules

The B→D transition form factor（TFF）f₊^B→D（q²）is determined by the D-meson leading-twist distribution amplitude（DA）,φ_2;D,if the proper chiral current correlation function is adopted within the light-cone QCD sum rules.It is therefore significant to make a comprehensive study of DA φ_2;D and its impact on f₊^B→D（q²）.In this paper,we calculate the moments of φ_2;D with the QCD sum rules under the framework of the background field theory.New sum rules for the leading-twist DA moments <（?）ⁿ>_D to fourth order and up to dimension-six condensates are presented.At the scale μ=2GeV,the values of the first four moments are:<（?）¹>_D＝-0.418_-0.22^+0.021,<（?）²>_D= 0.289_-0.022^+0.023,...