Forward-backward ratio for the $\phi$-meson in p-Pb collisions at $\snn = 5.02$ TeV as a function of $\pt$, in the rapidity range $2.96 < |y| < 3.53$ common to the two rapidity regions considered in the analysis. Error bars and boxes represent statistical and systematic uncertainties, respectively. The blue box on the left represents the bin-to-bin correlated systematic uncertainty, see Table 7. Predictions from HIJING and DPMJET are also shown for comparison.