Possibility of $T_{c\bar{s}}(2900)$ as the resonance-like structure induced by threshold effects

TL;DR

This paper explores whether the observed $T_{c\bar{s}}(2900)$ structure can be explained by threshold effects and triangle singularities in rescattering processes, rather than being a genuine resonance.

Contribution

It demonstrates that certain triangle singularities can produce narrow peaks mimicking resonance structures like $T_{c\bar{s}}(2900)$ in experimental spectra.

Findings

TS peak near $D^*K^*$ threshold can simulate $T_{c\bar{s}}(2900)$

Broad $ ho$ width smears the TS peak near $D_s^*\rho$ threshold

Predicted TS signal around $DK$ threshold from $\\chi_{c0}K D$ loop

Abstract

We investigate the process $B\to \bar{D}D_s \pi$ via several rescattering processes. It is shown that the triangle singularity (TS) peak around the $D^*K^*$ threshold generated from the $\chi_{c1}K^* D^*$ loop is relatively narrow, which may simulate the resonance-like structure $T_{c\bar{s}}(2900)$ recently observed by LHCb in the $D_s\pi$ spectrum. However, the TS peak around the $D_s^*\rho$ threshold generated from the $D^{**} D_s^* \rho$ loop is smoothed by the broad width of $\rho$, which itself can hardly describe the $T_{c\bar{s}}(2900)$ structure. A TS signal around the $DK$ threshold generated from the $\chi_{c0}K D $ loop is also predicted.