| Article | |
| Report number | arXiv:2310.13043 ; CERN-TH-2023-193 |
| Title | The first limit on invisible decays of $B_s$ mesons comes from LEP |
| Author(s) | Alonso-Álvarez, Gonzalo (McGill U. ; Toronto U.) ; Escudero Abenza, Miguel (CERN) |
| Publication | 2024-05-31 |
| Imprint | 2023-10-19 |
| Number of pages | 5 |
| Note | 3.5 pages + references. v2: minor improvement on the analysis by using mean PDG value of B fragmentation ratios. Added appendix with recasted ALEPH bounds on partially invisible flavor-violating B decays such as B -> tau a and B -> rho a, with a being an axion-like particle. v3: matches published version. Added clarifications about the analysis. We now use the CLs method to derive the bounds |
| In: | Eur. Phys. J. C 84 (2024) 553 |
| DOI | 10.1140/epjc/s10052-024-12936-x |
| Subject category | hep-ex ; Particle Physics - Experiment ; hep-ph ; Particle Physics - Phenomenology |
| Abstract | Motivated by the recent evidence for $B^+\to K^+\bar{\nu} \nu$ decays at Belle II, we point out that fully invisible $B_d$ and $B_s$ meson decays are strongly constrained by LEP. A reinterpretation of an old inclusive ALEPH search for $b$-hadron decays with large missing energy allows us to place the limits $\mathrm{Br}(B_d \rightarrow \mathrm{invisible}) < 1.4\times10^{-4}$ and $\mathrm{Br}(B_s \rightarrow \mathrm{invisible}) < 5.6\times10^{-4}$, both at $90\%$ CL. The $B_d$ limit is only a factor of 6 looser than the world-leading one provided by the BaBar collaboration, while the $B_s$ one is the first limit in the literature on this decay mode. These results are relevant in the context of new light states coupled to quarks and exemplify the power of a future Tera-$Z$ factory at FCC-ee to look for $B$ meson decays containing missing energy. |
| Copyright/License | preprint: (License: arXiv nonexclusive-distrib 1.0) publication: © 2024 The Author(s) (License: CC-BY-4.0), sponsored by SCOAP³ |
Corresponding record in: Inspire
Record created 2023-10-24, last modified 2024-09-13
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