2017/09/27 by Hao-Yang Jing, Xin Liu, Zhen-Jun Xiao
Chemistry · Physics and Astronomy · #Algorithm #B meson #Branching fraction #Chemistry #Crystallography #Factorization #Hadron #High-Energy Particle Collisions Research #Particle physics #Particle physics theoretical and experimental studies #Perturbative QCD #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #hep-ph
paper · pdf · doi:10.1103/physrevd.96.113002
published as Phys. Rev. D 96, 113002 (2017) · 13 pages, 1 figure, 5 tables, revtex file
arxiv created 2017/09/27 · openalex created_date 2017/10/06 · openalex publication_date 2017/12/11 · arxiv updated 2017/12/20 · openalex updated_date 2026/08/05
We calculate the branching ratios and polarization fractions of the B\ensuremath→a1b1 decays in the perturbative QCD(pQCD) approach at leading order, where a1(b1) stands for the axial-vector a1(1260)[b1(1235)] state. By combining the phenomenological analyses with the perturbative calculations, we find the following results: (a) the large decay rates around 10^\ensuremath-5 to 10^\ensuremath-6 of the B\ensuremath→a1b1 decays dominated by the longitudinal polarization(except for the B+\ensuremath→b1+a10 mode) are predicted and basically consistent with those in the QCD factorization(QCDF) within errors, which are expected to be tested by the Large Hadron Collider and Belle-II experiments. The large B0\ensuremath→a10b10 branching ratio could provide hints to help explore the mechanism of the color-suppressed decays. (b) the rather different QCD behaviors between the a1 and b1 mesons result in the destructive(constructive) contributions in the nonfactorizable spectator diagrams with a1(b1) emission. Therefore, an interesting pattern of the branching ratios appears for the color-suppressed B0\ensuremath→a10a10,a10b10, and b10b10 modes in the pQCD approach, BR(B0\ensuremath→b10b10)>BR(B0\ensuremath→a10b10)\ensuremath\gtrsim\phantom\rule0ex0exBR(B0\ensuremath→a10a10), which is different from BR(B0\ensuremath→b10b10)\ensuremath∼BR(B0\ensuremath→a10b10)\ensuremath\gtrsimBR(B0\ensuremath→a10a10) in the QCDF and would be verified at future experiments. (c) the large naive factorization breaking effects are observed in these B\ensuremath→a1b1 decays. Specifically, the large nonfactorizable spectator(weak annihilation) amplitudes contribute to the B0\ensuremath→b1+a1^\ensuremath-(B+\ensuremath→a1+b10\phantom\rule[-0.0ex]1em0.0exand\phantom\rule[-0.0ex]1em0.0exB+\ensuremath→b1+a10) mode(s), which demand confirmations via the precise measurements. Furthermore, the different phenomenologies shown among B\ensuremath→a1b1, B\ensuremath→a1a1, and B\ensuremath→b1b1 decays are also expected to be tested stringently, which could shed light on the typical QCD dynamics involved in these modes, even further distinguish those two popular pQCD and QCDF approaches.