arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1908.11557hep-phhep-exnucl-exnucl-th
收藏

$D^+_s \to π^+ π^0 η$衰变的理论解释和$a_0(980)$的性质

Theoretical interpretation of the $D^+_s \to π^+ π^0 η$ decay and the nature of $a_0(980)$

Raquel Molina, Ju-Jun Xie, Wei-Hong Liang, Li-Sheng Geng, Eulogio Oset

摘要:

在最近的一篇论文\cite{Ablikim:2019pit}中,BESIII合作报告了所谓的纯$W$ -湮灭衰变$D^+_s \to a^+_0(980) π^0$和$D_s^+ \to a^0_0(980)π^+$的首次观察。然而,令人困惑的是,测得的绝对分支分数比其他测得的纯$W$湮灭衰变的绝对分支分数大至少一个数量级。此外,发现两种衰变模式之间的相对相位约为180度。在这封信中,我们表明,所有这些都可以很容易地理解,如果$a_0(980)$是一个动态生成的状态,从$\bar{K} K$和$πη$相互作用的耦合通道。在这种情况下,$D^+_s$衰减经由内部$W$发射而不是$W$湮灭进行,其具有比$W$湮灭更大的衰减速率。提出的衰变机制和$a_0(980)$的分子性质也提供了一个自然的解释,测量两种衰变模式之间的负干扰。

英文摘要:

In a recent paper \cite{Ablikim:2019pit}, the BESIII collaboration reported the so-called first observation of pure $W$-annihilation decays $D^+_s \to a^+_0(980) π^0$ and $D_s^+ \to a^0_0(980)π^+$. The measured absolute branching fractions are, however, puzzlingly larger than those of other measured pure $W$-annihilation decays by at least one order of magnitude. In addition, the relative phase between the two decay modes is found to be about 180 degrees. In this letter, we show that all these can be easily understood if the $a_0(980)$ is a dynamically generated state from $\bar{K} K$ and $πη$ interactions in coupled channels. In such a scenario, the $D^+_s$ decay proceeds via internal $W$ emission instead of $W$-annihilation, which has a larger decay rate than $W$-annihilation. The proposed decay mechanism and the molecular nature of the $a_0(980)$ also provide a natural explanation to the measured negative interference between the two decay modes.

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。

↑