Observation of double J/$ψ$ meson production in pPb collisions at $\sqrt{s_\mathrm{NN}}$ = 8.16 TeV
Fuente:
arXiv
Enregistré dans:
| Auteur principal: | |
|---|---|
| Format: | Preprint |
| Publié: |
2024
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866916470691201024 |
|---|---|
| author | CMS Collaboration |
| author_facet | CMS Collaboration |
| contents | The first observation of the concurrent production of two J/$ψ$ mesons in proton-nucleus collisions is presented. The analysis is based on a proton-lead (pPb) data sample recorded at a nucleon-nucleon center-of-mass energy of 8.16 TeV by the CMS experiment at the CERN LHC and corresponding to an integrated luminosity of 174.6 nb$^{-1}$. The two J/$ψ$ mesons are reconstructed in their $μ^+μ^-$ decay channels with transverse momenta $p_\mathrm{T}$ $\gt$ 6.5 GeV and rapidity $\lvert y \rvert$ $\lt$ 2.4. Events where one of the J/$ψ$ mesons is reconstructed in the dielectron channel are also considered in the search. The pPb $\to$ J/$ψ$J/$ψ$ + X process is observed with a significance of 5.3 standard deviations. The measured inclusive fiducial cross section, using the four-muon channel alone, is $σ$(pPb $\to$ J/$ψ$J/$ψ$ + X) = 22.0 $\pm$ 8.9 (stat) $\pm$ 1.5 (syst) nb. A fit of the data to the expected rapidity separation for pairs of J/$ψ$ mesons produced in single (SPS) and double (DPS) parton scatterings yields $σ^{\mathrm{pPb} \to \mathrm{J}/ψ\mathrm{J}/ψ+\mathrm{X}}_\text{SPS}$ = 16.5 $\pm$ 10.8 (stat) $\pm$ 0.1 (syst) nb and $σ^{\mathrm{pPb} \to \mathrm{J}/ψ\mathrm{J}/ψ+ \mathrm{X}}_\text{DPS}$ = 5.4 $\pm$ 6.2 (stat) $\pm$ 0.4 (syst) nb, respectively. This latter result can be transformed into a lower bound on the effective DPS cross section, closely related to the squared average interparton transverse separation in the collision, of $σ_\text{eff}$ $\gt$ 1.0 mb at 95% confidence level. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2407_03223 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Observation of double J/$ψ$ meson production in pPb collisions at $\sqrt{s_\mathrm{NN}}$ = 8.16 TeV CMS Collaboration Nuclear Experiment High Energy Physics - Experiment The first observation of the concurrent production of two J/$ψ$ mesons in proton-nucleus collisions is presented. The analysis is based on a proton-lead (pPb) data sample recorded at a nucleon-nucleon center-of-mass energy of 8.16 TeV by the CMS experiment at the CERN LHC and corresponding to an integrated luminosity of 174.6 nb$^{-1}$. The two J/$ψ$ mesons are reconstructed in their $μ^+μ^-$ decay channels with transverse momenta $p_\mathrm{T}$ $\gt$ 6.5 GeV and rapidity $\lvert y \rvert$ $\lt$ 2.4. Events where one of the J/$ψ$ mesons is reconstructed in the dielectron channel are also considered in the search. The pPb $\to$ J/$ψ$J/$ψ$ + X process is observed with a significance of 5.3 standard deviations. The measured inclusive fiducial cross section, using the four-muon channel alone, is $σ$(pPb $\to$ J/$ψ$J/$ψ$ + X) = 22.0 $\pm$ 8.9 (stat) $\pm$ 1.5 (syst) nb. A fit of the data to the expected rapidity separation for pairs of J/$ψ$ mesons produced in single (SPS) and double (DPS) parton scatterings yields $σ^{\mathrm{pPb} \to \mathrm{J}/ψ\mathrm{J}/ψ+\mathrm{X}}_\text{SPS}$ = 16.5 $\pm$ 10.8 (stat) $\pm$ 0.1 (syst) nb and $σ^{\mathrm{pPb} \to \mathrm{J}/ψ\mathrm{J}/ψ+ \mathrm{X}}_\text{DPS}$ = 5.4 $\pm$ 6.2 (stat) $\pm$ 0.4 (syst) nb, respectively. This latter result can be transformed into a lower bound on the effective DPS cross section, closely related to the squared average interparton transverse separation in the collision, of $σ_\text{eff}$ $\gt$ 1.0 mb at 95% confidence level. |
| title | Observation of double J/$ψ$ meson production in pPb collisions at $\sqrt{s_\mathrm{NN}}$ = 8.16 TeV |
| topic | Nuclear Experiment High Energy Physics - Experiment |
| url | https://arxiv.org/abs/2407.03223 |