In search for signals of the DD̅ bound state X(3700) from study of the B⁺ → D⁺ D^- K⁺, B⁰ → D⁺ D^- K⁰ and Λ_b → D⁺ D^- Λ reactions

@misc{ren2026search,
  title = {{In search for signals of the $D\barD$ bound state $X(3700)$ from study of the $B^+ \to D^+ D^- K^+$, $B^0 \to D^+ D^- K^0$ and $Λ_b \to D^+ D^- Λ$ reactions}},
  author = {Xiu-Lei Ren and Hai-Peng Li and Wei-Hong Liang and Chu-Wen Xiao and Eulogio Oset},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2606.14644},
  eprint = {2606.14644},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2606.14644},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - In search for signals of the DD̅ bound state X(3700) from study of the B^+ → D^+ D^- K^+, B^0 → D^+ D^- K^0 and Λ_b → D^+ D^- Λ reactions
AU  - Xiu-Lei Ren
AU  - Hai-Peng Li
AU  - Wei-Hong Liang
AU  - Chu-Wen Xiao
AU  - Eulogio Oset
PY  - 2026
DA  - 2026/09/05
PB  - arXiv
DO  - 10.48550/arxiv.2606.14644
UR  - https://arxiv.org/abs/2606.14644
AB  - We perform a theoretical study of the B^+ → D^+ D^- K^+, B^0 → D^+ D^- K^0 and Λ_b → D^+ D^- Λ reactions by looking at the production mechanisms, with special emphasis in the final state interaction of the charmed mesons, which gives rise to the X(3930), coupling strongly to D_sD̅_s, and another state that we call X(3700), coupling strongly to D D̅ that qualifies as a D D̅ bound state. The combined study of all these reactions shows that the final state interaction responsible for the production of these resonances is more important in the B^+ → D^+ D^- K^+ reaction than in the Λ_b → D^+ D^- Λ one. We have taken this into account and shown that normalizing the D^+ D^- mass distributions to the same value at the peak of the ψ(3770) production, the two mass distributions are quite different in a range of 10 MeV above the D^+ D^- threshold, with a value about an order of magnitude bigger for the B^+ → D^+ D^- K^+ reaction than for the Λ_b → D^+ D^- Λ one. The D^+D^- mass distribution by itself also shows an enhancement of about one order of magnitude in the presence of the X(3700) with respect to a calculation where this resonance is absent. We make a call to measure these magnitudes in the coming LHCb upgrades, which would bring great support to the existence of the bound D^+ D^- state.
ER  -