The cut I used are: 1 one cluster reconstructed in vdc: R.vdc.u1.nclust==1&&R.vdc.v1.nclust==1&&R.vdc.u2.nclust==1&&R.vdc.v2.nclust==1 2 R.cer.asum_p>600 3 One track reconstructed: R.tr.n==1 4 R.ps.mult>0&&R.sh.mult>0 The variable I plotted is (R.ps.e+R.sh.e)/(p0*(1+R.gold.dp)), and p0=1GeV for run 20269. The resolution is about 5.6%
Figure 1