ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA
英文摘要:
We calculate low-energy contributions to the weak form factors of B(D) --> pi in the frameworks of heavy-light chiral perturbation theory (HLCPT) including vector meson effects. The calculation is done to the order 1/Lambda(csb)(3) in the expansion with respect to Lambda(csb) (Lambda(csb) is the chiral symmetry breaking scale) at O(1) in 1/m(Q) expansion and to 1/Lambda(csb)(2) at 1/m(Q). It is found that nonperturbative effects dominate B(D) --> pi form factors and the values are comparable with those from quark model approach.
