$R_{\rm pPb}$ of prompt \PJpsi versus rapidity (left panel) and as a function of \pt\ at mid-rapidity (right panel), compared to theoretical calculations Statistical uncertainties are represented by vertical error bars, while open boxes correspond to systematic uncertainties Results from the LHCb experiment at backward and forward rapidity are shown in the left panel  The box around $R_{\rm pPb} = 1$ in the right panel shows the size of the correlated relative uncertainty Results from various models  are also shown, see text for details