On the lineshapes manifested by the molecular candidate a1(1420)

by Dr Mao-Jun Yan (Southwest University)

Wednesday 21 Jan 2026, 15:15 → 16:00 Asia/Shanghai

摘要： The axial current in QCD plays a crucial role in understanding low-energy strong interactions, as it couples to both pseudoscalar mesons and axial-vector mesons. While the former case has been widely studied, theoretical and experimental investigations of the latter remain relatively poor. In this talk, I focus on the structure of the isovector ($I=1, J^{PC}=1^{++}$) axial-vector meson. By analyzing the peak structure around $1.4~\mathrm{GeV}$ in the $f_0(980)\pi$ invariant mass spectrum in the process $\pi p \to p\, f_0(980)\pi$, as well as the dip structure near $1.4~\mathrm{GeV}$ in the $\rho\pi$ invariant mass spectrum in $\gamma p \to n\, 3\pi$, I find evidence that supports identifying the $a_1(1420)$ as a molecular candidate of $K^{\ast}\bar K$. This interpretation suggests $a_1(1420)$ acts as the flavor partner of the $W_{c1}$, providing insight into the nature of axial-vector mesons and their role in strong interactions.

个人简介： 严茂俊，2019年毕业于中国科学院理论物理研究所，随后在北京航空航天大学和中国科学院理论物理研究所从事博士后研究，2024年入职西南大学；主要从事低能强相互作用理论，奇特强子态和强子谱学中的运动学奇异性等方面研究。