Gespeichert in:
| 1. Verfasser: | |
|---|---|
| Format: | Preprint |
| Veröffentlicht: |
2026
|
| Schlagworte: | |
| Online-Zugang: | https://arxiv.org/abs/2605.16228 |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| _version_ | 1866918504544862208 |
|---|---|
| author | ATLAS Collaboration |
| author_facet | ATLAS Collaboration |
| contents | The first observation of a new meson state decaying into $B_c^+$ and a photon is presented using a dataset of $pp$ collisions at a centre-of-mass energy $\sqrt{s} = 13$ TeV collected by the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb$^{-1}$. The $B_c^+$ mesons are reconstructed from a three-muon final state from $B_c^+\to J/ψ(μ^+μ^-)μ^+ν_μX$ decays, along with photons reconstructed via conversions to electron-positron pairs in the detector material. The new state is observed with a significance that exceeds 8 standard deviations. The mass difference between the new meson state and the ground-state $B_c^+$ meson is measured to be $64.5 \pm 1.4\text{(stat.)}^{+1.0}_{-1.4}\text{(syst.)}$ MeV. This corresponds to a mass for the observed state of $6339.0 \pm 1.4\text{(stat.)}^{+1.0}_{-1.4}\text{(syst.)}\pm 0.3(m_{B_c^+})$ MeV, where the last uncertainty is due to the precision of the best knowledge of the $B_c^+$ meson mass. The low mass difference value matches the theory expectations for the lowest vector state of the $\bar{b}c$ quarkonium system, the $B_c^{*+}$ meson. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2605_16228 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | Observation of a $B_c^{*+}$ meson with the ATLAS detector ATLAS Collaboration High Energy Physics - Experiment The first observation of a new meson state decaying into $B_c^+$ and a photon is presented using a dataset of $pp$ collisions at a centre-of-mass energy $\sqrt{s} = 13$ TeV collected by the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb$^{-1}$. The $B_c^+$ mesons are reconstructed from a three-muon final state from $B_c^+\to J/ψ(μ^+μ^-)μ^+ν_μX$ decays, along with photons reconstructed via conversions to electron-positron pairs in the detector material. The new state is observed with a significance that exceeds 8 standard deviations. The mass difference between the new meson state and the ground-state $B_c^+$ meson is measured to be $64.5 \pm 1.4\text{(stat.)}^{+1.0}_{-1.4}\text{(syst.)}$ MeV. This corresponds to a mass for the observed state of $6339.0 \pm 1.4\text{(stat.)}^{+1.0}_{-1.4}\text{(syst.)}\pm 0.3(m_{B_c^+})$ MeV, where the last uncertainty is due to the precision of the best knowledge of the $B_c^+$ meson mass. The low mass difference value matches the theory expectations for the lowest vector state of the $\bar{b}c$ quarkonium system, the $B_c^{*+}$ meson. |
| title | Observation of a $B_c^{*+}$ meson with the ATLAS detector |
| topic | High Energy Physics - Experiment |
| url | https://arxiv.org/abs/2605.16228 |