arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2110.00520hep-ex
收藏

用BABAR研究用初态辐射的过程$e^+e^-\to π^+π^-π^0$

Study of the process $e^+e^-\to π^+π^-π^0$ using initial state radiation with BABAR

The BABAR Collaboration

备注：
35 pages, 28 figures, corrected cross section in Table IV
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

过程$e^+e^-\to π^+π^-π^0γ$的研究在一个中心的质量能量附近的$Υ(4S)$共振使用的数据样本469 FB $^{-1}$收集的BABAR探测器在PEP-II对撞机。我们已经进行了精确的测量的$e^+e^-\to π^+π^-π^0$截面的质心能量范围从0.62到3.5 GeV。在$ω$和$ϕ$共振的能量区域中，以1.3%的系统不确定度测量横截面。利用测量的$e^+e^-\to π^+π^-π^0$截面计算了从阈值到2.0 GeV的μ子磁异常的首阶强子贡献为$(45.86 \pm 0.14 \pm 0.58)\times 10^{-10}$。根据对测量的$3π$质谱的拟合，我们确定了共振参数$Γ(ω\to e^+e^-){\cal B}(ω\to π^+π^-π^0)=(0.5698\pm0.0031\pm0.0082) \mbox{ keV}$、$Γ(ϕ\to e^+e^-){\cal B}(ϕ\to π^+π^-π^0)=(0.1841\pm0.0021\pm0.0080) \mbox{ keV}$和${\cal B}(ρ\to 3π)=(0.88\pm 0.23\pm 0.30)\times 10^{-4}$。$ρ\to 3π$信号的意义大于$6σ$。对于$J/ψ$共振，我们测量了产物${Γ(J/ψ\to e^+e^-){\cal B}(J/ψ\to 3π)}=(0.1248\pm0.0019\pm0.0026)\mbox{ keV}$。

英文摘要：

The process $e^+e^-\to π^+π^-π^0γ$ is studied at a center-of-mass energy near the $Υ(4S)$ resonance using a data sample of 469 fb$^{-1}$ collected with the BABAR detector at the PEP-II collider. We have performed a precise measurement of the $e^+e^-\to π^+π^-π^0$ cross section in the center-of-mass energy range from 0.62 to 3.5 GeV. In the energy regions of the $ω$ and $ϕ$ resonances, the cross section is measured with a systematic uncertainty of 1.3\%. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the measured $e^+e^-\to π^+π^-π^0$ cross section from threshold to 2.0 GeV is $(45.86 \pm 0.14 \pm 0.58)\times 10^{-10}$. From the fit to the measured $3π$ mass spectrum we have determined the resonance parameters $Γ(ω\to e^+e^-){\cal B}(ω\to π^+π^-π^0)=(0.5698\pm0.0031\pm0.0082) \mbox{ keV}$, $Γ(ϕ\to e^+e^-){\cal B}(ϕ\to π^+π^-π^0)=(0.1841\pm0.0021\pm0.0080) \mbox{ keV}$, and ${\cal B}(ρ\to 3π)=(0.88\pm 0.23\pm 0.30)\times 10^{-4}$. The significance of the $ρ\to 3π$ signal is greater than $6σ$. For the $J/ψ$ resonance we have measured the product ${Γ(J/ψ\to e^+e^-){\cal B}(J/ψ\to 3π)}=(0.1248\pm0.0019\pm0.0026)\mbox{ keV}$.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑