Measurement of inclusive J/ψ pair production cross section in pp collisions at s =13 TeV

Abstract

The production cross section of inclusive $J/\ensuremath{\psi}$ pairs in $pp$ collisions at a center-of-mass energy $\sqrt{s}=13$ TeV is measured with ALICE. The measurement is performed for $J/\ensuremath{\psi}$ in the rapidity interval $2.5<y<4.0$ and for transverse momentum ${p}_{T}>0$. The production cross section of inclusive $J/\ensuremath{\psi}$ pairs is reported to be $10.3\ifmmode\pm\else\textpm\fi{}2.3\phantom{\rule{0.16em}{0ex}}(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}1.3\phantom{\rule{0.16em}{0ex}}(\mathrm{syst}.)$ nb in this kinematic interval. The contribution from nonprompt $J/\ensuremath{\psi}$ (i.e., originated from beauty-hadron decays) to the inclusive sample is evaluated. The effective double-parton scattering cross section is computed, neglecting the single-parton scattering contribution.