arXiv subjects

De-Hua Yao

Publications and source records attributed to De-Hua Yao.

3 recordsLinked to original sources

arXiv2025

Studying the $B^{0} \to J/ψh_{1}$ decays with $h_{1}(1170)-h_{1}(1415)$ mixing in the perturbative QCD approach

In this paper, we study the $B^{0} \to J/ψh_{1}$ decays for the first time by using perturbative QCD approach up to the presently known next-to-leading order accuracy. The vertex corrections present significant contribution to the amplitude. In the calculation, the mixing between two light axial-vector mesons $h_{1}(1170)$ and $h_{1}(1415)$ are also studied in detail. The observables including the branching ratios, polarization fractions and $CP$ asymmetries are predicted and discussed explicitly. It is found that the $B^{0} \to J/ψh_{1}$ decays have relatively large branching fractions, which are generally at the order of ${\cal O}(10^{-6}\sim10^{-3})$, and thus are possible to be observed by the LHCb and Belle-II experiments in the near future. Moreover, they are very sensitive to the mixing angle $θ$ and can be used to test the values of $θ$. In addition, some ratios between the branching fractions of $B^{0} \to J/ψh_{1}$ decays can provide much stronger constraints on $θ$ due to their relatively small theoretical errors. The $B^{0} \to J/ψh_{1}$ decays are generally dominated by the longitudinal polarization contributions, specifically, $f_{L}(B^{0} \to J/ψh_{1})>80\%$, except for the case that $θ\sim 35^\circ$ and $-55^\circ$. Unfortunately, the direct $CP$ asymmetries of $B^{0} \to J/ψh_{1}$ decays are too small to be observed soon even if the effect of $θ$ is considered. The future precise measurements on $B^{0} \to J/ψh_{1}$ decays are expected for testing these theoretical findings and exploring the interesting nature of $h_{1}(1170)$ and $h_{1}(1415)$.

hep-ph↗

arXiv2023

Phenomenological studies on neutral $B$-meson decays into $J/ψf_1$ and $η_c f_1$

The axial-vector mesons $f_1(1285)$ and $f_1(1420)$ are particularly viewed as the mixtures of flavor states $f_n$ and $f_s$ with mixing angle $φ$. In order to determine this angle, we study the $B_{d,s}^0\to J/ψf_1(1285,1420)$ and $B_{d,s}^0\to η_c f_1(1285,1420)$ decays in perturbative QCD (PQCD) approach, including the effects of vertex corrections, nonfactorizable diagrams and penguin operators. Not only the branching fractions, but also the direct $CP$ asymmetries and the polarization fractions are calculated. It is found that the branching fractions of these decays are large enough to be measured in the running LHCb and Belle-II experiments. Moreover, in comparison with the observed ${\cal B}(B_{d,s}^0 \to J/ψf_1(1285))$, $B_s^0 \to (J/ψ, η_c) f_1(1420)$ decays have large branching fractions, which could be measured promisingly through $f_1(1420) \to K_S^0 K^\pm π^\mp$ in experiments. We also propose several ratios that could be used to further constrain the absolute value of the mixing angle $φ$, but its sign cannot be determined yet in these decays. The direct CP asymmetries of these decays indicate the penguin pollution in the $B_d^0 \to (J/ψ, η_c) f_1$ decays cannot be neglected. We acknowledge that there are large theoretical uncertainties arising from the distribution amplitudes of axial-vector mesons and charmonium states, and more precise nonperturbative parameters are called. The comparisons between our results and future experimental data would help us to understand the nature of $f_1$ states and to test the PQCD approach.

hep-ph↗

arXiv2021

$B_{d,s}^0 \to f_1 f_1$ decays with $f_1(1285)-f_1(1420)$ mixing in the perturbative QCD approach

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.

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