发表机构
Guizhou Minzu University（贵州民族大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究采用夸克-反夸克图像，通过光锥求和规则计算$B_s\to f_0(1500)$跃迁形状因子，预测准四体稀有衰变分支比，为实验提供理论参考。
AI 中文摘要
$f_0(1500)$是轻标量谱中一个相当特殊的共振态。与邻近的其他共振态相比，它具有出乎意料的窄衰变宽度。由于其质量区域与$f_0(1370)$和$f_0(980)$强烈重叠，物理学家长期以来对其内部结构争论不休。为探究这一问题，本工作采用传统的夸克-反夸克$q\bar{q}$图像，研究了$f_0(1500)$共振在准四体衰变道中的行为。基于此，我们构建了基于光锥谐振子模型的twist-2光锥分布振幅（LCDA）方案，并给出了其在$\mu_0=1~\mathrm{GeV}$和$\mu_k=3~\mathrm{GeV}$下对于$n=1,3,5$的矩$\langle \xi ^n _{2;f_0(1500)} \rangle |_\mu$和Gegenbauer矩$a_{n;f_0(1500)}(\mu)$。同时，利用QCD光锥求和规则计算了$B_s\to f_0(1500)$跃迁形状因子（TFFs）。然后，我们在大反冲点获得了三个TFFs，即$f_ + ^{B_s f_0(1500)}(0)= 0.390_{-0.046}^{ + 0.047}$，$f_-^{B_s f_0(1500)}(0)= -0.460_{-0.055}^{ + 0.051}$，和$f_{\rm T}^{B_s f_0(1500)}(0)= 0.568^{ + 0.069}_{-0.065}$。此外，我们利用简化的$z(q^2)$级数展开将TFFs外推到整个物理$q^2$区域。随后，我们计算了准四体稀有衰变$B_s \to f_0(1500)(\to \pi^ + \pi^-)\ell^ + \ell^-$和$B_s \to f_0(1500)(\to \pi^ + \pi^-)\nu\bar{\nu}$的分支比。为作比较，我们还给出了在窄宽度近似下相应三体衰变的结果。最后，我们展示了准四体衰变$B_s\to f_0(1500)(\to\pi^ + \pi^-)\mu^ + \mu^-$的双微分衰变宽度$d^2\Gamma/ds dq^2$的分布。我们希望我们的预测能为未来的实验测量和唯象研究提供有用的理论参考。
英文摘要
The $f_0(1500)$ is a quite special resonance in the light scalar spectrum. Compared with other nearby resonance, it has an unexpectedly narrow decay width. Since its mass region overlaps strongly with $f_0(1370)$ and $f_0(980)$, physicists have long debated its internal structure. To explore this issue, this work adopted the conventional quark-antiquark $q\bar{q}$ picture and investigated the behavior of the $f_0(1500)$-resonance in quasi-four-body decay channels. Based on this, we constructed a twist-2 light-cone distribution amplitude(LCDA) schemes based on the light-cone harmonic oscillator model, and presented their moments $\langle ξ^n _{2;f_0(1500)} \rangle |_μ$ and Gegenbauer moments $a_{n;f_0(1500)}(μ)$ at $μ_0=1~\mathrm{GeV}$ and $μ_k= 3~\mathrm{GeV}$ for $n=1,3,5$. Meanwhile, the $B_s\to f_0(1500)$ transition form factors (TFFs) are calculated by using the QCD light-cone sum rule. Then, we obtained the three TFFs at large recoil point, {\it i.e.,} $f_ + ^{B_s f_0(1500)}(0)= 0.390_{-0.046}^{ + 0.047}$, $f_-^{B_s f_0(1500)}(0)= -0.460_{-0.055}^{ + 0.051}$, and $f_{\rm T}^{B_s f_0(1500)}(0)= 0.568^{ + 0.069}_{-0.065}$. In addition, we extrapolated TFFs to the whole physical $q^2$-region by using the simplified $z(q^2)$-series expansion. Then we computed the branching fractions of the quasi-four-body rare decays $B_s \to f_0(1500)(\to π^ + π^-)\ell^ + \ell^-$ and $B_s \to f_0(1500)(\to π^ + π^-)ν\barν$. For comparison, we also present the results of the corresponding three-body decays obtained under the narrow-width approximation. Finally, we show the distribution of the double-differential decay width $d^2Γ/ds dq^2$ for the quasi-four-body decay $B_s\to f_0(1500)(\toπ^ + π^-)μ^ + μ^-$. We hope that our predictions can provide a useful theoretical reference for future experimental measurements and phenomenological research.
Comments31 pages, 3 figures, comments welcome
