Figure 1

Transverse momentum distribution of opposite-sign dimuons with $1.5 < \mmm < 2.0$ \GeVmass and $2.5 < y < 4.0$. The data are represented by full circles with vertical bars for the statistical uncertainties and horizontal bars for the interval width The solid line represents the fit to the data, and the dashed and dot-dashed lines represent the fit components.