本文研究$B\toΛ\bar p M$衰变的前后角不对称性，计算π与ρ道结果，并作出含矢量介子无粲重子衰变的首个预言，可供LHCb和Belle II检验。
摘要：
Belle测量的$\bar B^0\toΛ\bar pπ^+$前后角不对称性（${\cal A}_{FB}$）给出了介于$-30\\%$至$-50\\%$范围内的实验值。在我们的研究中，发现${\cal A}_{FB}[\bar B^0\toΛ\bar p π^+(B^-\to Λ\bar pπ^0)]$可高达$(-14.6^{+0.9}_{-1.5}\pm 6.9)\\%$。此外，我们给出${\cal A}_{FB}[\bar B^0\toΛ\bar p ρ^+(B^-\to Λ\bar pρ^0)] =(4.1^{+2.8}_{-0.7}\pm 2.0)\\%$，这是无粲$B\to{\bf B\bar B'}M$衰变中涉及矢量介子的首个预言。尽管${\cal A}_{FB}(B\toΛ\bar p M)$指示了由类时间区域中研究较少的重子形状因子引起的角关联，LHCb和Belle II仍有能力开展实验检验。
英文摘要：
The forward-backward angular asymmetry (${\cal A}_{FB}$) for $\bar B^0\to Λ\bar pπ^+$ measured by Belle has presented an experimental value in the range of $-30\%$ to $-50\%$. In our study, we find that ${\cal A}_{FB}[\bar B^0\toΛ\bar p π^+(B^-\to Λ\bar pπ^0)]$ can be as large as $(-14.6^{+0.9}_{-1.5}\pm 6.9)\%$. In addition, we present ${\cal A}_{FB}[\bar B^0\toΛ\bar p ρ^+(B^-\to Λ\bar pρ^0)] =(4.1^{+2.8}_{-0.7}\pm 2.0)\%$ as the first prediction involving a vector meson in the charmless $B\to{\bf B\bar B'}M$ decays. While ${\cal A}_{FB}(B\toΛ\bar p M)$ indicates an angular correlation caused by the rarely studied baryonic form factors in the timelike region, LHCb and Belle~II are capable of performing experimental examinations.
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Factorization and angular distribution asymmetries in charmful baryonic B decays
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Initial state angular asymmetries in high energy p+A collisions: spontaneous breaking of rotational symmetry by a color electric field and C-odd fluctuations
Improving the sensitivity to CP-violation in the Higgs sector is one of the pillars of the precision Higgs programme at the Large Hadron Collider. We present a simple method that allows CP-sensitive observables to be directly constructed from the output of neural networks. We show that these observables have improved sensitivity to CP-violating effects in the production and decay of the Higgs boson, when compared to the use of traditional angular observables alone. The kinematic correlations identified by the neural networks can be used to design new analyses based on angular observables, with…
We analyze the decay processes of ${\bf B}_c \to {\bf B}_n M$ with the $SU(3)_F$ flavor symmetry and spin-dependent amplitudes, where ${\bf B}_c({\bf B}_n)$ and $M$ are the anti-triplet charmed (octet) baryon and nonet meson states, respectively. In the $SU(3)_F$ approach, it is the first time that the decay rates and up-down asymmetries are fully and systematically studied without neglecting the ${\cal O}(\overline{15})$ contributions of the color anti-symmetric parts in the effective Hamiltonian. Our results of the up-down asymmetries based on $SU(3)_F$ are quite different from the previous …
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Spin content of constituent quarks and one-spin asymmetries in inclusive processes
我们考虑在包容强子产生中观察到的单自旋不对称性的机制。主要的作用属于夸克-反夸克云的轨道角动量在组成夸克的内部结构。我们认为，在π介子生产的不对称性的起源是保持这种内部的角轨道动量的微扰相的QCD从非微扰相的过渡下的结果。非微扰强子结构是基于手征夸克模型的结果。PACS编号：11.30.Qc、12.40.Pp、13.75.Ni、13.88.+ e
We review the two and three-body baryonic $B$ decays with the dibaryon (${\bf B\bar B'}$) as the final states. Accordingly, we summarize the experimental data of the branching fractions, angular asymmetries, and $CP$ asymmetries. Using the $W$-boson annihilation (exchange) mechanism, the branching fractions of $B\to {\bf B \bf \bar B'}$ are shown to be interpretable. In the approach of perturbative QCD counting rules, we study the three-body decay channels. In particular, we review the $CP$ asymmetries of $B\to {\bf B\bar B'}M$, which are promising to be measured by the LHCb and Belle~II exper…
Using the Bethe-Salpeter equation (BSE) we investigate the forward-backward asymmetries $( A_{FB}) $ in $Λ_b \rightarrow Λl^+ l^-(l=e,μ,τ)$ in the quark-diquark model. This approach provides precise form factors that are different from those of QCD sum rules. We calculate the rare decay form factors for $Λ_b \rightarrow Λl^+ l^-$ and investigate the (integrated) forward-backward asymmetries in these decay channels. We find that the integrated $A^l_{FB}$, $\bar{A}^l_{FB}(Λ_b \rightarrow Λe^+ e^-) \simeq -0.1371 $, $\bar{A}^l_{FB}(Λ_b \rightarrow Λμ^+ μ^- ) \simeq -0.1376 $, $\bar{A}^l_{FB}(Λ_b …
