论文标题
美元
$B_{d,s}^0 \to f_1 f_1$ decays with $f_1(1285)-f_1(1420)$ mixing in the perturbative QCD approach
论文作者
论文摘要
我们研究了$ b_ {d，s}^0 \ f_1 f_1 $ $衰减在扰动QCD（pqcd）方法的框架中，带有引用的值$ ϕ__ {f_1} \ sim 24^\ circ $。在这里，$ f_1 $表示轴向矢量介子$ f_1（1285）$和$ f_1（1420）$，带有混合角度$ ϕ__ {f_1} $在夸克味的基础上。观察到的$ b_s^0 \至f_1 f_1 $衰减等观测值，直接CP违规和极化分数是首次预测。我们发现：（i）几乎纯粹的企鹅模式$ b_s^0 \ to f_1 f_1 $具有$ 10^{ - 6} \ sim 10^{ - 5} $的顺序，由于cabibbo-kobayashi-maskakawa增强率和通常的结构性干扰，$ b_s $ and ymplitudes $ b b b b d f _ $ b_s^0 \ to f_s f_s $带有$ f_n $，而$ f_s $是$ f_1 $ mesons; （ii）可观察物在PQCD方法中从弱歼灭图中获得重要贡献。特别是，如果没有歼灭贡献，$ b_s^0 \至f_1（1420）f_1（1420）$分支比率将降低约81％，其纵向极化分数将减少约43％。 （iii）$ b_ {d，s}^0 \对f_1 f_1 $衰减率的依赖性$ ϕ_ {f_1} $表现出一些有趣的线形状，其确认将有助于约束$ ϕ_ {f_1} $ inversaly的确定。所有的PQCD预测都在等待大型强子对撞机美丽和/或Belle-II实验的（近）将来的检查，以进一步了解轴向矢量膜的特性以及从考虑的衰减模式中释放出的扰动动力学。
We investigate the $B_{d,s}^0 \to f_1 f_1$ decays in the framework of perturbative QCD(PQCD) approach with a referenced value $ϕ_{f_1} \sim 24^\circ$. Here, $f_1$ denotes the axial-vector mesons $f_1(1285)$ and $f_1(1420)$ with mixing angle $ϕ_{f_1}$ in the quark-flavor basis. The observables such as branching ratios, direct CP violations, and polarization fractions of the $B_s^0 \to f_1 f_1$ decays are predicted for the first time. We find that: (i) the almost pure penguin modes $B_s^0 \to f_1 f_1$ have large branching ratios in the order of $10^{-6} \sim 10^{-5}$ due to the Cabibbo-Kobayashi-Maskawa enhancement and generally constructive interferences between the amplitudes of $B_s^0 \to f_n f_s$ and $B_s^0 \to f_s f_s$ with $f_n$ and $f_s$ being the quark-flavor states of $f_1$ mesons; (ii) The observables receive important contributions from the weak annihilation diagrams in the PQCD approach. In particular, without the annihilation contributions, the $B_s^0 \to f_1(1420) f_1(1420)$ branching ratio will decrease about 81% and its longitudinal polarization fraction will reduce around 43%. And (iii) the dependence of the $B_{d,s}^0 \to f_1 f_1$ decay rates on $ϕ_{f_1}$ exhibits some interesting line shapes, whose confirmations would be helpful to constrain the determination of $ϕ_{f_1}$ inversely. All the PQCD predictions await for the (near) future examinations at Large Hadron Collider beauty and/or Belle-II experiments to further understand the properties of the axial-vector mesons and the perturbative dynamics released from the considered decay modes.
