arXiv subjects

Sheng-Bo Wu

Publications and source records attributed to Sheng-Bo Wu.

4 recordsLinked to original sources

arXiv2026

Scrutinizing lepton flavor universality and transition form factor correlation from charmed meson semileptonic decay into light strange vector $K^*$ meson

In this paper, we calculate the transition form factors (TFFs) $A_{1,2}(q^2)$ and $V(q^2)$ of $D_s^+ \to K^{*0}$ decays by using the QCD light-cone sum rule (QCD LCSR) and constructing a correlation function containing the usual current, in which the twist-2 transverse and longitudinal light-cone distribution amplitudes (LCDAs) $\phi^\lambda_{2;K^{*0}}(x,\mu_0)$ with $\lambda=(\bot,\|)$ of the $K^{*0}$ meson constitute the main source of theoretical uncertainty. Based on this, we construct these LCDAs using the light-cone harmonic oscillator model. Subsequently, the TFFs obtained in the large recoil region are $A_{1}(0)=0.579_{-0.028}^{+0.024}$, $A_{2}(0)=0.414_{-0.023}^{+0.021}$, and $V(0)=0.830_{-0.020}^{+0.020}$, and the corresponding ratios are obtained to be $r_V=1.433_{-0.090}^{+0.110}$ and $r_2=0.715_{-0.067}^{+0.075}$. Furthermore, we predict the correlation of TFFs and their corresponding ratios. Then, we extrapolate the TFFs over the whole physical $q^2$-region and calculate the decay widths and branching fractions for the semileptonic decays $D_s^+\to K^{*0}\ell^+\nu_{\ell}$. The results are $\mathcal{B}(D_s^+\to K^{*0}e^+\nu_{e})=(2.05_{-0.16}^{+0.13})\times 10^{-3}$ and $\mathcal{B}(D_s^+\to K^{*0}\mu^+\nu_{\mu})=(1.95_{-0.15}^{+0.13})\times 10^{-3}$. Meanwhile, we calculated the branching fraction ratio $\mathcal{R}_{\mu/e}^{K^{*0}}$ to be $0.950_{-0.002}^{+0.004}$. In addition, we extract values of the CKM matrix element, obtaining $|V_{cd}|_{(e\text{-Channel})} = 0.225_{-0.005}^{+0.005}$ and $|V_{cd}|_{(\mu\text{-Channel})} = 0.227_{-0.004}^{+0.011}$. Finally, we calculated the forward-backward asymmetry parameters for the $D_s^+\to K^{*0} \ell^+\nu_{\ell}$ decay.

hep-ph↗

arXiv2026

Addressing the lightest $S$-wave strange $K_0^*(700)/\kappa$ resonance in four-body semileptonic $\bar{B}_s^0 \to K^0\pi^+ \ell^-\bar{\nu}_\ell$ decays

As the lightest strange scalar resonance, $K_0^*(700)$ (also called $\kappa$) has a large width and resides close to the $K\pi$ threshold, leading to a longstanding debate about its internal structure. Within the framework of the conventional quark-antiquark ($q\bar{q}$) picture, this paper attempts to research the behaviors of $K_0^*(700)$ resonance in the four-body final state decays. Firstly, we investigates the $K_0^*(700)$ resonance one twist-2 and two twist-3 light-cone distribution amplitudes (LCDAs), {\it i.e.} $\phi_{2;K_0^*(700)}(x, \mu)$ and $\phi_{3;K_0^*(700)}^{p;\sigma}(x, \mu)$ by constructing light-cone harmonic oscillator model. For the longitudinal distribution characteristics of the twist-2 LCDA, two typical parametrization schemes, {\it i.e.} $\varphi_{2;K_0^*(700)}^{\rm (S1)}(x)$ and $\varphi_{2;K_0^*(700)}^{\rm (S2)}(x)$, are adopted in this paper. Meanwhile, it has enriched theoretical predictions for the first ten-order LCDAs $\xi$-moments. Subsequently, we apply the QCD light-cone sum rules approach to compute the $\bar B_s^0 \to K_0^*(700)$ transition form factors (TFFs) $f_\pm^{\bar B_s^0 K_0^*(700)}(q^2)$ and $f_{\rm T}^{\bar B_s^0 K_0^*(700)}(q^2)$ by taking into account the perturbative $\mathcal{O}(\alpha_s)$ corrections to the twist-2 LCDAs terms. By using the simplified series expansion parameterization, these TFFs are extrapolated over the full physical region. Then, we calculate the differential decay widths and branching fractions for four-body semileptonic decay $\bar{B}_s^0 \to K^0\pi^+ \ell^-\bar{\nu}_\ell$ with $\ell= (e, \mu, \tau)$ via the $S$-wave $K_0^*(700)$ resonance, respectively. We expect that the obtained prediction results will provide valuable insights for future experiments and theoretical research.

hep-ph↗

arXiv2025

Footprint in fitting $B \to D$ vector form factor and determination for $D$-meson leading-twist LCDA

In this paper, we fit the $B\to D$ vector transition form factor (TFF) by using the data measured by \textsl{BABAR} and Belle Collaborations within Monte Carlo (MC) method. Meanwhile, the $B\to D$ TFF is also calculated by using the QCD light-cone sum rules approach (LCSRs) within right-handed chiral current correlation function. In the TFF, $D$-meson leading-twist light-cone distribution amplitude (LCDA) is the most important non-perturbative input parameter, the precise behavior of which is mainly determined by the parameter $B_{2;D}$ in the light-cone harmonic oscillator model. Through fitting the TFF, we determine the value $B_{2;D}=0.445$. Then, we present the curve of $D$-meson leading-twist LCDA in comparison with other theoretical approaches. Subsequently, the $B\to D$ TFF $f_{+}^{BD}(q^2)$ at the large recoil region is $f_{+}^{BD}(0)=0.648_{-0.063}^{+0.067}$, which is compared in detail with theoretical estimates and experimental measurements. Furthermore, we calculated the decay width and branching fractions of the Cabibbo-favored semileptonic decays $B\to D\ell^+\nu_{\ell}$, which lead to the results $\mathcal{B}(B^0\to D^-\ell ^+\nu _{\ell}) =(2.10_{-0.38}^{+0.44})\times 10^{-2}$ and $\mathcal{B}(B^+\to \bar{D}^0\ell ^+\nu _{\ell}) =(2.26_{-0.41}^{+0.48})\times 10^{-2}$. Finally, we predict the CKM matrix element with two scenarios $|V_{cb}|_{\rm SR}=41.55_{-4.50}^{+4.91}\times 10^{-3}$ and $|V_{cb} |_{\rm MC}=41.47_{-2.66}^{+2.55 }\times 10^{-3}$ from $B^0\to D^-\ell^+\nu_{\ell}$, $|V_{cb}|_{\rm SR}=40.54_{-3.80}^{+4.33}\times 10^{-3}$ and $|V_{cb} |_{\rm MC}=40.46_{-1.38}^{+1.40}\times 10^{-3}$ from $B^+\to \bar{D}^0\ell^+\nu_{\ell}$ which are in good agreement with theoretical and experimental predictions.

hep-ph↗

arXiv2024

Investigation for $D^+ \to π^+ ν\barν$ decay process within QCDSR approach

In the paper, we investigate the charmed meson rare decay process $D^+ \to π^+ν\barν$ by using QCD sum rules approach. Firstly, the pion twist-2 and twist-3 distribution amplitude $ξ$-moments $\langleξ_{2;π}^n\rangle|_μ$ up to 10th-order and $\langle ξ_{3;π}^{(p,σ),n}\rangle|_μ$ up to fourth-order are calculated by using QCD sum rule under background field theory. After constructing the light-cone harmonic oscillator model for pion twist-2, 3 DAs, we get their behaviors by matching the calculated $ξ$-moments. Then, the $D\to π$ transition form factors are calculated by using QCD light-cone sum rules approach. The vector form factor at large recoil region is $f_+^{D\toπ}(0) = 0.627^{+0.120} _{-0.080}$. By taking the rapidly $z(q^2,t)$ converging simplified series expansion, we present the TFFs and the corresponding angular coefficients in the whole squared momentum transfer physical region. Furthermore, we display the semileptonic decay process $\bar D^0 \to π^+ e\bar ν_e$ differential decay widths and branching fraction with ${\cal B}(\bar D^0\toπ^+e\barν_e) = 0.308^{+0.155}_{-0.066} \times 10^{2}$. The $\bar D^0\toπ^+e\barν_e$ differential/total predictions for forward-backward asymmetry, $q^2$-differential flat terms and lepton polarization asymmetry are also given. After considering the non-standard neutrino interactions, the predictions for the $D^+ \to π^+ ν\barν$ branching fraction is ${\cal B}(D^+ \to π^+ {ν}{\barν}) = 1.85^{+0.93}_{-0.46}\times10^{-8}$.

hep-ph↗