CERN Accelerating science

Representative diagrams of SPS (left) and DPS (center and right) contributions to the production of two \JPsi mesons in $\pPb$ collisions.

Dimuon invariant mass distributions of the \pPb\ events passing all selection criteria, shown as a 2D map (left panel, with the numbers indicating the counts per bin and the red circle indicating the double \JPsi meson signal region) and its 1D projections for each pair (center and right panels). In the 1D projections, the measured data are represented by the points (with vertical bars showing their Poisson statistical uncertainties), the solid curve shows the overall signal$\,+\,$background fit to the data, and the red hashed area shows the signal yields for the \TJPsi process.

Dimuon invariant mass distributions of the \pPb\ events passing all selection criteria, shown as a 2D map (left panel, with the numbers indicating the counts per bin and the red circle indicating the double \JPsi meson signal region) and its 1D projections for each pair (center and right panels). In the 1D projections, the measured data are represented by the points (with vertical bars showing their Poisson statistical uncertainties), the solid curve shows the overall signal$\,+\,$background fit to the data, and the red hashed area shows the signal yields for the \TJPsi process.

Dilepton invariant mass distributions of the \pPb\ events passing all selection criteria, shown as a 2D map (left panel, with the numbers indicating the counts per bin and the red circle indicating the double \JPsi meson signal region) and its 1D projections for each pair (center and right panels). In the 1D projections, the measured data are represented by the points (vertical bars showing their Poisson statistical uncertainties), the solid curve shows the overall signal$\,+\,$background fit to the data, and the red hashed area shows the signal yields for the \TJPsi process.

Dilepton invariant mass distributions of the \pPb\ events passing all selection criteria, shown as a 2D map (left panel, with the numbers indicating the counts per bin and the red circle indicating the double \JPsi meson signal region) and its 1D projections for each pair (center and right panels). In the 1D projections, the measured data are represented by the points (vertical bars showing their Poisson statistical uncertainties), the solid curve shows the overall signal$\,+\,$background fit to the data, and the red hashed area shows the signal yields for the \TJPsi process.

Distribution of rapidity separation (\cmsLeft) between the two \JPsi mesons in data (black markers), fitted template of the expected DPS contribution (blue histogram) normalized to the data outside of the SPS-dominated region (as described in the text), and fitted SPS$\,+\,$DPS distribution (red histogram). Distribution of azimuthal separation (\cmsRight) between the two \JPsi mesons measured in data (black markers) and expected DPS contribution (blue histogram), and SPS$\,+\,$DPS sum (red histogram), with the relative normalization derived from the \DeltaY distribution (left panel), as explained in the text.

Distribution of rapidity separation (\cmsLeft) between the two \JPsi mesons in data (black markers), fitted template of the expected DPS contribution (blue histogram) normalized to the data outside of the SPS-dominated region (as described in the text), and fitted SPS$\,+\,$DPS distribution (red histogram). Distribution of azimuthal separation (\cmsRight) between the two \JPsi mesons measured in data (black markers) and expected DPS contribution (blue histogram), and SPS$\,+\,$DPS sum (red histogram), with the relative normalization derived from the \DeltaY distribution (left panel), as explained in the text.

Comparison of the effective DPS cross sections $\sigmaeffdps$ extracted in this work (red arrow lower limit) with the same parameter derived in \pp measurements of double- and triple-quarkonium production~\cite{Lansberg:2019adr,Aaboud:2016fzt,Abazov:2014qba,Shao:2016wor,Aaij:2016bqq,Lansberg:2016muq,Lansberg:2017chq,CMS:2021qsn} (blue circles), as well as in final states with jets~\cite{UA2:1991apc,CDF:1993sbj,D0:2015rpo,Khachatryan:2015pea}, $\gamma+$\,jets~\cite{CDF:1997yfa,D0:2009apj,D0:2014owy}, $\PW+$\,jets~\cite{ATLAS:2013aph,CMS:2013huw}, and double \PW bosons~\cite{CMS:2022pio} (black squares). The asterisk shown in a few legend entries indicates that the result has been obtained by more recent phenomenological analyses of the experimental data.