Measurement of psi(2S) production cross-sections in proton-proton collisions at 7 and 13 TeV

Abstract

The cross-sections of $\ddot{I}ˆ(2S)$ meson production in proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$ are measured with a data sample collected by the LHCb detector corresponding to an integrated luminosity of $275p{\mathrm{b}}^{-1}$. The production cross-sections for prompt $\ddot{I}ˆ(2S)$ mesons and those for $\ddot{I}ˆ(2S)$ mesons from $b$-hadron decays ($\ddot{I}ˆ(2S)-\mathrm{from}-b$) are determined as functions of the transverse momentum, $p_{\mathrm{T}}$, and the rapidity, $y$, of the $\ddot{I}ˆ(2S)$ meson in the kinematic range $2<p_{\mathrm{T}}<20\mathrm{GeV}/c$ and $2.0<y<4.5$. The production cross-sections integrated over this kinematic region are \begin{equation*} \begin{split} σ(\mbox{prompt }ψ(2S),13~\mathrm{TeV}) &= {1.430 \pm 0.005(\mathrm{stat}) \pm 0.099 (\mathrm{syst})μ\mathrm{b}},\\ σ(ψ(2S)\mathrm{-from-}b,13~\mathrm{TeV})&={0.426 \pm 0.002(\mathrm{stat}) \pm0.030 (\mathrm{syst})μ\mathrm{b}}. \end{split} \end{equation*} A new measurement of $\ddot{I}ˆ(2S)$ production cross-sections in $pp$ collisions at $\sqrt{s}=7\mathrm{TeV}$ is also performed using data collected in 2011, corresponding to an integrated luminosity of $614p{\mathrm{b}}^{-1}$.The integrated production cross-sections in the kinematic range $3.5<p_{\mathrm{T}}<14\mathrm{GeV}/c$ and $2.0<y<4.5$ are \begin{equation*} \begin{split} σ(\mbox{prompt }ψ(2S),7~\mathrm{TeV}) &={0.471 \pm0.001 (\mathrm{stat}) \pm 0.025 (\mathrm{syst})μ\mathrm{b}},\\ σ(ψ(2S)\mathrm{-from-}b,7~\mathrm{TeV}) &={0.126\pm0.001 (\mathrm{stat}) \pm0.008 (\mathrm{syst})μ\mathrm{b}}. \end{split} \end{equation*} All results show reasonable agreement with theoretical calculations.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2018-049.html