The ρ-meson longitudinal leading-twist distribution amplitude

• Main Authors: Hai-Bing Fu, Xing-Gang Wu, Hua-Yong Han, Yang Ma, Huan-Yu Bi
• Format: Article
• Language: English
• Published: Elsevier 2014-11-01
• Series: Physics Letters B
• Online Access: http://www.sciencedirect.com/science/article/pii/S0370269314007138

In the present paper, we suggest a convenient model for the vector ρ-meson longitudinal leading-twist distribution amplitude ϕ2;ρ‖, whose distribution is controlled by a single parameter B2;ρ‖. By choosing proper chiral current in the correlator, we obtain new light-cone sum rules (LCSR) for the B→ρ TFFs A1, A2 and V, in which the δ1-order ϕ2;ρ‖ provides dominant contributions. Then we make a detailed discussion on the ϕ2;ρ‖ properties via those B→ρ TFFs. A proper choice of B2;ρ‖ can make all the TFFs agree with the lattice QCD predictions. A prediction of |Vub| has also been presented by using the extrapolated TFFs, which indicates that a larger B2;ρ‖ leads to a larger |Vub|. To compare with the BABAR data on |Vub|, the longitudinal leading-twist DA ϕ2;ρ‖ prefers a doubly-humped behavior.