next up previous contents
Next: Neutral Resonances Up: Simulations Previous: Global Charge Conservation   Contents

Efficiency and Background

With a detector efficiency less than 100%, the value of $ v(Q)$ is pushed towards 1, as seen in fig. 3.3. The result is consistent with (3.18).

Figure 3.3: With $ p_e<1$ the value of $ v(Q)$ is pushed towards 1.
\begin{figure}\centerline{\hbox{\epsfxsize=10cm\epsffile{images/vQeffic.eps}}} \end{figure}

The same thing happens when a fraction of the particles in an event originates from a background distribution of uncorrelated positive and negative particles. Fig. 3.4 shows the corresponding behavior. (Here $ p_+=p_-=0.5$ for the background particles.) The result is consistent with (3.17).

Figure 3.4: With $ f_{bkg}>0$ the value of $ v(Q)$ is pushed towards 1.
\begin{figure}\centerline{\hbox{\epsfxsize=10cm\epsffile{images/vQbkg.eps}}} \end{figure}

The $ \nu _{dyn}$ measure is unaffected by efficiency changes, whereas it is still sensitive to background contributions. In these simulations $ \nu_{dyn}=-0.004 \cdot (1-f_{bkg}) / (1-\varepsilon^2)$, as can be seen in fig. 3.5.

Figure 3.5: The value of $ \nu _{dyn}$ is affected by a background contribution. (Here $ \varepsilon $=0 is used.)
\begin{figure}\centerline{\hbox{\epsfxsize=10cm\epsffile{images/nubkg_v2.eps}}} \end{figure}

next up previous contents
Next: Neutral Resonances Up: Simulations Previous: Global Charge Conservation   Contents
Henrik Tydesjo 2003-02-24