Study of $\psi(2S)$ production and cold nuclear matter effects in $pPb$ collisions at $\sqrt{s_{NN}}=5~TeV$

The production of $\psi(2S)$ mesons is studied in dimuon final states using proton-lead collision data collected by the LHCb detector. The data sample corresponds to an integrated luminosity of $1.6~nb^{-1}$. The nucleon-nucleon centre-of-mass energy of the proton-lead collisions is $\sqrt{s_{NN}}=5~TeV$. The measurement is performed using $\psi(2S)$ mesons with transverse momentum $p_T$ less than $14~GeV/c$ and rapidity in the ranges 1.5<$y$<4.0 and -5.0<$y$<-2.5 in the nucleon-nucleon centre-of-mass system. The forward-backward production ratio and the nuclear modification factor are determined for $\psi(2S)$ mesons.