# Figure 2

 Top panels: inclusive distribution of positive (left) and negative (right) charge muon candidates measured in the Pb-going (top) and p-going (bottom) data taking periods. The results of the MC template fit for the extraction of the $\mu^{+} \leftarrow \mathrm{W}^{+}$ and $\mu^{-} \leftarrow \mathrm{W}^{-}$ signal is shown. In this case, the central value of the FONLL calculations is used for the background description while POWHEG with the CT10 PDF set paired with EPS09NLO is used for W and Z boson production. Bottom panels: relative difference of data and the extrapolated fit results in the range $10< \pt< 80~ \gev/c$.