Measurement of the $J/\ddot{I}ˆ$ pair production cross-section in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$

Abstract

The production cross-section of $J/\ddot{I}ˆ$ pairs is measured using a data sample of $pp$ collisions collected by the LHCb experiment at a centre-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$, corresponding to an integrated luminosity of $279\pm 11\mathrm{p}{\mathrm{b}}^{-1}$. The measurement is performed for $J/\ddot{I}ˆ$ mesons with a transverse momentum of less than $10\mathrm{GeV}/c$ in the rapidity range $2.0<y<4.5$. The production cross-section is measured to be $15.2\pm 1.0\pm 0.9\mathrm{nb}$. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the $J/\ddot{I}ˆ$ pair are measured and compared to theoretical predictions.

All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-057.html