Solution of $a_2/a_1$ sign problem in heavy meson decays: nonfactorizable soft gluons in nonleptonic heavy meson decays

B. Tseng, Hsiang-nan Li

For the first time, a solution to the $a_2/a_1$ sign problem in heavy meson decay based on PQCD factorization theorems. The point is to include QCD evolution effort characteristic…