12 unlike-sign and like-sign background invariant mass spec- tra are shown in Fig. 10. In this analysis, we cannot resolve individual states of the Υ family due to the limited statistics, finite mo- mentum resolution, and electron bremsstrahlung result- ing from the large material budget during the 2006 run. Therefore, the yield reported here is for the combined Υ(1S+2S+3S) states. The total dielectron unlike-sign yield after like-sign background subtraction has three contributions. In order to separate these three contributions, we ob- tain parametrizations for the expected shapes of each of the three components of the dielectron unlike-sign yield. The contribution from the Υ states is obtained by the same simulations that were used to obtain the detec- tor efficiency. The reconstructed invariant mass shape for the 1S, 2S, and 3S states are individually obtained. Each of the shapes from the simulation is fit with a functional form introduced by the Crystal-Ball experi- ment [31], which can accommodate detector resolution and losses due to bremsstrahlung in the detector mate- rial, and has the form: Requiring that the function and its derivative be contin- uous constrains the constants A and B to be: We fix the parameters of the three Crystal-Ball functions representing the three Υ states and then adjust the rela- tive scales according to the average branching ratios and according to the ratios of cross sections shown in Ta- ble II. The overall integral of the Crystal-Ball functions combined this way is left as a free parameter in the fit, which allows us to obtain the Υ yield. Figure 11 shows the data used to obtain the Υ and continuum yields. The data points are the unlike-sign e $^{+}$e − signal after subtracting the like-sign combinatorial background. The background subtraction is done bin-by- bin. The error bars shown are statistical. The fit includes the contributions from the Υ(1S+2S+3S) states and the continuum contributions from Drell-Yan and b - ¯ b shown as the solid-line function. The Υ states are modeled with FIG. 11: The e $^{+}$e − signal after subtracting the like-sign com- binatorial background. The solid line is the function used to fit the data, composed of: (a) three Crystal-Ball functions (Eq. 2) that represent the combined Υ(1S+2S+3S) line shape, (b) the Drell-Yan, and (c) the b - ¯ b contributions. We fit the data using the integral of the fit function in each mass bin, shown by the dashed-line histogram. The sum of the two con- tinuum contributions is shown by the dot-dashed line. The integral of the Crystal-Ball functions provides the net Υ yield. FIG. 10: Unlike-sign raw yield N + − (filled circles) in the re- gion | y$_{ee}$ | < 0 . 5, where y$_{ee}$ is the pairwise rapidity, and like- $_{sign combinatorial background 2}$√$_{N}$$_{++}$$_{N}$$_{−−}$ (line histogram). The background is fit to an exponential multiplied with an er- ror function representing the turn-on of the STAR Υ trigger (dashed line). ) 2  (GeV/c ee m 4 6 8 10 12 14 16 Counts 0 10 20 30 40 50 60 +- Unlike-Sign, N -- N ++ N Like-Sign, 2 Like-sign fit ) 2  (GeV/c ee m 4 6 8 10 12 14 16 unlike - like sign counts -10 0 10 20 30 40 50 60 STAR =200 GeV s p+p,  |<0.5 ee |y -- N ++ N  - 2 +- N  + DY, Fit b  + b- Integral of Fit +DY b b- A. Υ Line Shape 1. The Υ states. 2. The Drell-Yan continuum. 3. The b - ¯ b continuum. f ( m ) = N · { exp( − ( m − µ ) 2 2 σ 2 ) , for m − µ σ > − α A · ( B m − µ σ ) − $^{n}$, for m − µ σ ≤ − α (2) A = ( n | α | ) n · exp ( − | α | 2 2 ) B = n | α | − | α | (3)