Eur. Phys. J. C (2006) 46: 367-377
https://doi.org/10.1140/epjc/s2006-02476-y

Theoretical Physics

Factorization and polarization in two charmed-meson B decays

¹ Department of Physics, National Cheng-Kung University, Tainan, 701, Taiwan
² Department of Physics, National Tsing-Hua University, Hsin-Chu, 300, Taiwan
³ Institute of Physics, Academia Sinica, Taipei, 115, Taiwan
⁴ National Center for Theoretical Sciences, Hsinchu, Taiwan

^* e-mail: weizt@phys.sinica.edu.tw

Received: 15 November 2005
Published online: 17 March 2006

Abstract

We provide a comprehensive test of factorization in the heavy–heavy B decays motivated by the recent experimental data from the BELLE and BABAR collaborations. The penguin effects are not negligible in the B decays with two pseudoscalar mesons. The direct CP asymmetries are found to be a few percent. We give estimates on the weak annihilation contributions by analogy to the observed annihilation-dominated processes. The N_c insensitivity of branching ratios indicates that the soft final state interactions are not dominant. We also study the polarizations in B→D^*D_(s) ^* decays. The power law shows that the transverse perpendicular polarization fraction is small. The effects of the heavy quark symmetry breaking caused by the perturbative QCD and power corrections on the transverse polarization are also investigated.