| Preprint | |
| Report number | CERN-EP-2026-123 ; arXiv:2605.04348 ; LHCB-PAPER-2026-004 |
| Title | Observation of the charmless purely baryonic decay $\mathinner{\mathit{\Lambda}^0_b\!\to \mathit{\Lambda} p \overline{p}}$ |
| Corporate author(s) | LHCb Collaboration |
| Publication | 2026 |
| Collaboration | LHCb Collaboration |
| Imprint | 07 May 2026 |
| Subject category | Particle Physics - Experiment |
| Accelerator/Facility, Experiment | CERN LHC ; LHCb |
| Keywords | LHCb |
| Abstract | A search for the charmless purely baryonic decay $\mathinner{\mathit{\Lambda}^0_b\!\to \mathit{\Lambda} p \overline{p}}$ is performed using proton-proton collision data recorded by the LHCb experiment at a centre-of-mass energy of $\sqrt{s}=13\,\text{TeV}$ and corresponding to an integrated luminosity of $6.0\,\text{fb}^{-1}$. The signal decay is observed with a significance of 5.1 standard deviations. Its branching fraction is measured for the first time, relative to that of the topologically similar decay $\mathinner{\mathit{\Lambda}^0_b\!\to \mathit{\Lambda} K^+ K^-}$. Contributions from intermediate charmonium resonances decaying to the $p \overline{p}$ and $K^+ K^-$ final states are explicitly excluded with a requirement on the invariant mass of the companion hadron system, $m(h\bar{h}) < 2.85\,\text{GeV}$, where $h$ stands for a proton or a charged kaon. The relative branching fraction is found to be$$ \frac{\mathcal{B}(\mathinner{\mathit{\Lambda}^0_b\!\to \mathit{\Lambda} p\overline{p}})}{\mathcal{B}(\mathinner{\mathit{\Lambda}^0_b\!\to \mathit{\Lambda} K^+ K^-})} = (5.1 \pm 1.3_{\text{(stat)}} \pm 0.3_{\text{(syst)}}) \times 10^{-2} \,.$$ |
| Other source | INSPIRE |
| Copyright/License | Preprint: © 2026 CERN (License: CC-BY-4.0) |
| Submitted by | lhcb.secretariat@cern.ch |
Δημιουργία εγγραφής 2026-05-07, τελευταία τροποποίηση 2026-05-11
