Sensitivity study of $\bar{K}_1(1270)$ decay dynamics using four $D\to \bar{K}_1(1270)(\to \bar Kππ)e^+ν$ decay channels

Abstract

A sensitivity study for the measurement of $\bar{K}_1(1270)$ decay modes is performed using semileptonic $D$-meson decays. The BESIII experiment is taken as a case study, where a simultaneous analysis of $\bar{K}_1(1270)$ decays to the four thee-body final states $K^-π^+π^-$, $K^-π^+π^0$, $K_S^0π^+π^-$, and $K_S^0π^-π^0$ is presented and a model-independent determination of \mbox{$\mathcal{B}(\bar{K}_1(1270)\to \bar Kππ)$}, without requiring detailed knowledge of intermediate resonant contributions, is proposed.

Figures (2)

• Figure 1: Simultaneous fit to the $M_{\rm miss}^2$ distributions of the pseudo-datasets. The points with error bars are the pseudo-data, the red dashed lines represent the signal shapes, and the green dashed lines represent the combinatorial background shapes. The brown dashed lines denote the peaking backgrounds from $D\to \bar{K}\pi\pi\pi$ decays.
• Figure 2: The $\alpha$ pull distribution, illustrating the difference between the reconstructed value $\alpha'$ and the input value $\alpha_{\rm nominal}$ normalized by the estimated uncertainty $\sigma_{\alpha}$.