Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2509.13101 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866916952202543104 |
|---|---|
| author | ATLAS Collaboration |
| author_facet | ATLAS Collaboration |
| contents | A search for resonant structures in the $J/ψ+ψ$(2S) mass spectrum is performed using proton--proton collision data at $\sqrt{s}=13$ TeV, corresponding to an integrated luminosity of 140 fb$^{-1}$, recorded by the ATLAS experiment at the LHC. The decay channels of $J/ψ+ψ\text{(2S)} \rightarrow 4μ$ and $J/ψ+ψ\text{(2S)} \rightarrow 4μ+2π$ are analyzed. An excess near 6.9 GeV is observed in both channels with a combined significance of 8.9$σ$. No significant signal is observed near 7.2 GeV, and an upper limit on its yield relative to $X$(6900) is provided. A simultaneous fit with the di-$J/ψ$ channel is carried out under assumptions regarding the resonance interferences, yielding a ratio of the partial decay widths between the $J/ψ+ψ\text{(2S)}$ and di-$J/ψ$ channels of $1.08\pm 0.20_{-0.17}^{+0.40}$ for the resonance near 6.9 GeV. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_13101 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Observation of structures in the $J/ψ+ψ(2S)$ mass spectrum with the ATLAS detector ATLAS Collaboration High Energy Physics - Experiment A search for resonant structures in the $J/ψ+ψ$(2S) mass spectrum is performed using proton--proton collision data at $\sqrt{s}=13$ TeV, corresponding to an integrated luminosity of 140 fb$^{-1}$, recorded by the ATLAS experiment at the LHC. The decay channels of $J/ψ+ψ\text{(2S)} \rightarrow 4μ$ and $J/ψ+ψ\text{(2S)} \rightarrow 4μ+2π$ are analyzed. An excess near 6.9 GeV is observed in both channels with a combined significance of 8.9$σ$. No significant signal is observed near 7.2 GeV, and an upper limit on its yield relative to $X$(6900) is provided. A simultaneous fit with the di-$J/ψ$ channel is carried out under assumptions regarding the resonance interferences, yielding a ratio of the partial decay widths between the $J/ψ+ψ\text{(2S)}$ and di-$J/ψ$ channels of $1.08\pm 0.20_{-0.17}^{+0.40}$ for the resonance near 6.9 GeV. |
| title | Observation of structures in the $J/ψ+ψ(2S)$ mass spectrum with the ATLAS detector |
| topic | High Energy Physics - Experiment |
| url | https://arxiv.org/abs/2509.13101 |