First analysis of the $p$Pb pilot run data with LHCb

A first analysis of the data taken during the proton-lead pilot run is presented. The data sample corresponds to an integrated luminosity of $L_{\rm int}$ = 0.93 $\pm$ 0.05 $\mu$b$^{-1}$. A first measurement of the inelastic $p$Pb cross-section at a nucleon-nucleon centre-of-mass energy $\sqrt{s_{NN}}$ = 5.02 TeV, with at least one charged particle in the region 2.5 $<\eta_{\rm CM}$ < 4.5 and $p_{\rm T}$ > 0.2 GeV/$c$, yields $\sigma_{\rm {inel}}$ = 2.09 $\pm$ 0.12b, where the uncertainty is purely systematic. Clean signals of strange and charm flavour production are observed. In $p$Pb interactions the average multiplicity in the proton hemisphere is found to be about a factor two larger than in $pp$ interactions when extrapolating to the same nucleon-nucleon centre-of-mass energy.