$T_{\bar{c}\bar{s}1}^0$ production in the $B^+$ decays processes

TL;DR

The study investigates the production of the open-charm molecular candidate $T_{ar{c}\bar{s}1^0}$ as a $S$-wave bound state of $\bar{D}K^*$ with $I(J^P)=0(1^+)$ near $M\approx 2.7$ GeV, produced via meson-loop triangle diagrams in $B^+$ decays. Using an effective Lagrangian framework and monopole form factors, it estimates branching fractions for $B^+ \to D^{+}T_{ar{c}\bar{s}1^0}$ and $B^+ \to D^{*+}T_{ar{c}\bar{s}1^0}$ on the order of $10^{-4}$ and evaluates fit fractions in $B^+ \to D^{(*)+}D^{*-}K^+$ decays to be a few percent. The results suggest observable signals for $T_{ar{c}\bar{s}1^0}$ in $B^+ \to D^{*+}D^{*-}K^+$ at Belle II and LHCb and provide a concrete framework to test the molecular interpretation of open-charm tetraquark candidates. The work highlights the role of hadronic loops and form-factor choices in predicting production rates for near-threshold molecular states in heavy-flavor decays.

Abstract

In the present work, we studied the \tcs state production through the meson loop mechanism in the $B^+$ meson decays, where \tcs is considered as a $\bar{D}K^*$ molecular state with $J^P=1^+$. By employing the effective Lagrangian approach, we estimated the branching ratio of the $B^+ \to D^+ T_{\bar{c}\bar{s}1}^0 $ and $B^+ \to D^{*+} T_{\bar{c}\bar{s}1}^0$ processes and found them to be on the order of $10^{-5}\sim 10^{-4}$. The fit fraction of \tcs in different processes was also estimated. We propose to search for \tcs in the $B^+ \to D^{*+}\bar{D}^{*-}K^+$ process, which should be accessible to the Belle II and LHCb Collaborations.

Figures (3)

• Figure 1: Distributions of two-body invariant masses of $M(D^{*-}K^+)$ in the $B^+ \to D^{*-}D^+K^+$ process reported by LHCb Collaboration.
• Figure 2: Diagrams contributing to $B^+ \to D^{+} T_{\bar{c}\bar{s}1}^0$ (diagram (a)) and $B^+ \to D^{*+} T_{\bar{c}\bar{s}1}^0$ (diagram (b)) at the hadron level. Here, the $c\bar{s}$ refers to the considered charm-strange mesons.
• Figure 3: The branching fractions fo $B^+ \to T_{\bar{c}\bar{s}1}^0 D^{(*)}$ depending on the model parameter $\alpha$.