Unified study of $B_s^0 \to X(3872) π^+π^- (K^+ K^-)$ and $B_s^0 \to ψ(2S) π^+π^- (K^+ K^-)$ processes

Yun-Hua Chen

doi:10.1140/epjc/s10052-026-15426-4

paper

Unified study of $B_{s}^{0} \to X (3872) π^{+} π^{-} (K^{+} K^{-})$ and $B_{s}^{0} \to ψ (2 S) π^{+} π^{-} (K^{+} K^{-})$ processes

arXiv:2512.17754 · doi:10.1140/epjc/s10052-026-15426-4

Abstract

We perform a unified description of the experimental data of the $π^{+} π^{-}$ invariant mass spectra of $B_{s}^{0} \to ψ (2 S) π^{+} π^{-}$ , the $π^{+} π^{-}$ and $K^{+} K^{-}$ invariant mass spectra of $B_{s}^{0} \to X (3872) π^{+} π^{-} (K^{+} K^{-})$ , and the ratio of branch fractions $B [B_{s}^{0} \to X (3872) (K^{+} K^{-})_{non - ϕ}] / B [B_{s}^{0} \to X (3872) π^{+} π^{-})$ . The strong final state interactions between the two pseudoscalars are taken into account using a parametrization fulfilling unitarity and analyticity. We find that there is universality in the coupling constants for $B_{s}^{0} \to ψ (2 S) π^{+} π^{-}$ and $B_{s}^{0} \to J / ψ π^{+} π^{-}$ processes. While the couplings of $B_{s}^{0} \to X (3872) π^{+} π^{-}$ are about half of magnitude smaller than the couplings of $B_{s}^{0} \to ψ (2 S) π^{+} π^{-}$ , which indicates that the $X (3872)$ is different from a pure charmonium state. Furthermore, we find that the $f_{0} (1500)$ plays an important role in the $B_{s}^{0} \to ψ (2 S) π^{+} π^{-}$ and the $B_{s}^{0} \to X (3872) π^{+} π^{-} (K^{+} K^{-})$ processes, though the phase space of $B_{s}^{0} \to X (3872) f_{0} (1500)$ is small. Also we predict the ratio of branch fractions $B [B_{s}^{0} \to ψ (2 S) (K^{+} K^{-})_{non - ϕ}] / B [B_{s}^{0} \to ψ (2 S) π^{+} π^{-}]$ and the $K^{+} K^{-}$ invariant mass distribution of $B_{s}^{0} \to ψ (2 S) K^{+} K^{-}$ .

15 pages, 3 figures

Unified study of Bs0​→X(3872)π+π−(K+K−) and Bs0​→ψ(2S)π+π−(K+K−) processes

Abstract

References in corpus (13)

Unified study of $B_{s}^{0} \to X (3872) π^{+} π^{-} (K^{+} K^{-})$ and $B_{s}^{0} \to ψ (2 S) π^{+} π^{-} (K^{+} K^{-})$ processes