Some answers to the questions/comments at the
Heavy/Light presentation of March 17, 2005.
Outline : 1) Addition of the id quadrant cut (slides 2-3);
2) S/B ratios and vertex distributions (slides 4-5);
3) Mass distribution fits (slide 6);
4) Conclusions (slides 7);
5) Backup slides (8-12).
Guy Roche, April 7, 2005.
Slide 1.
1) Addition of the id quadrant cut.
North and South mass distributions for the three dimuon charge states.
Run 3 data - red points: cuts of March 17th - blue points : adding id quad cut (idq0!=idq1).
The same plots for Run 4 are in backup slide 8.
Only a slight
yield reduction
at low mass.
Slide 2.
North and South mass distributions for the dimuon background and signal.
Run 3 data - red points: cuts of March 17th - blue points : adding id quad cut (idq0!=idq1).
The same plots for Run 4 are in backup slide 9.
Again, a slight yield
reduction at low mass
is seen.
Slide 3.
2) S/B ratios and vertex distributions.
Dimuon background, signal and S/B ratio for the whole data (with id quad cut).
S/B ratio and accuracy (signal/error-on-signal) numbers at low mass (1.5-2.4 GeV) and high
mass (>= 4.5 GeV).
Summing bins of the above background and signal histos, the S/B ratios and accuracies are:
low mass S/B = 0.236  0.034, accuracy = 7.0; high mass S/B = 0.50  0.25, accuracy = 2.1.
From the numbers in backup slide 10, the average S/B ratios and accuracies (w idquad cut) are:
low mass S/B = 0.229  0.040, accuracy = 3.4; high mass S/B = 0.40  0.27, accuracy = 0.9.
Both sets of numbers are in good agreement, the second set is probably more reliable
Slide 4.
Vertex distributions for the whole data (with id quad cut), Run 3 and Run 4 plots in backup slides 11-12.
Like sign distributions are shown in North and South, so one can see the typical asymmetry of these, with
different shifts of the means.
The background calculation from the expression 2*sqrt((++)*(--)) has not been done as yet. Here, we just
subtract like sign from opposite sign dimuons in both arms, which yields at least a partial restauration of the
symmetry.
Slide 5.
3) Mass distribution fits.
Dimuon signal for the whole data (with id quad cut).
Same fit functions as of March 17. The fit option bug has been corrected; now it is LLI (was the default
2 method). The left plot fit uses the components J/, ’, open charm, and Drell-Yan (DY); all components
are introduced in the right fit, adding open beauty (BB) and the  family, their corresponding parameter
limits being set to 0-10 and 0-5, respectively.
The component yields are compatible with the previous ones (1293  47, 470  89 and 326  59 for the
left fit), but the errors are much smaller. Introducing the BB component slightly reduces the DY yield.
Slide 6.
5) Conclusions.
- Addition of the id quadrant cut has a slight effect at low mass. Being on the hardware trigger, it will
be used from now on.
- The S/B ratio is reasonnably well defined (0.23  0.04) at low mass (1.5-2.4 GeV) , and marginally
(0.4  0.3) at high mass (>= 4.5 GeV).
- The vertex distributions from the simple subtraction OS - LS seem to be close to symmetrical, while
they are significantly asymmetrical for all three charge states. Actual background subtraction will be
done next.
- The new mass distribution fits are consistent with the previous ones (just because the data did not
change much), but now the LLI (Log Likelihood and Integral over the bin width) options drastically
reduce the error. It is checked that constraining the beauty components to still high values just barely
affects the Drell-Yan component.
- A possible distortion of the J/ line shape is being investigated. The distorted yield should stay at
about or below a few % of that of a single gaussian. Will be completed next.
Slide 7.
6) Backup slides.
North and South mass distributions for the three dimuon charge states.
Run 4 data - red points: cuts of March 17th - blue points: adding id quad cut (idq0!=idq1).
Slide 8.
North and South mass distributions for the dimuon background and signal.
Run 4 data - red points: cuts of March 17th - blue points : adding id quad cut (idq0!=idq1).
Slide 9.
S/B ratio numbers at low mass (1.5-2.4 GeV) and high mass (>= 4.5 GeV),
cut1 = no id quad cut, cut2 = with idquad cut, Acc = accuracy = signal/error-on-signal.
The numbers were obtained from a counting of the dimuons in the relevant bins of the mass distribution
histos such as those shown in slide 2.
****************
Run 3
********************
**************** Numbers for North arm ********************
******* W. cut1, low mass = 1.5 to 2.4
+- = 917 , ++ = 533 , -- = 273 , S/B = 0.201972 +/- 0.0598011 , Acc = 3.71214
******* W. cut2, low mass = 1.5 to 2.4
+- = 911 , ++ = 531 , -- = 269 , S/B = 0.205216 +/- 0.0602352 , Acc = 3.75008
******* W. cut1, high mass >= 4.5
+- = 26 , ++ = 14 , -- = 4 , S/B = 0.737198 +/- 0.598814 , Acc = 1.66334
******* W. cut2, high mass >= 4.5
+- = 26 , ++ = 14 , -- = 4 , S/B = 0.737198 +/- 0.598814 , Acc = 1.66334
**************** Numbers for South arm ********************
******* W. cut1, low mass = 1.5 to 2.4
+- = 361 , ++ = 227 , -- = 106 , S/B = 0.16362 +/- 0.0918442 , Acc = 1.92688
******* W. cut2, low mass = 1.5 to 2.4
+- = 357 , ++ = 226 , -- = 106 , S/B = 0.15327 +/- 0.0912892 , Acc = 1.80753
******* W. cut1, high mass >= 4.5
+- = 13 , ++ = 10 , -- = 2 , S/B = 0.453444 +/- 0.692369 , Acc = 0.811146
******* W. cut2, high mass >= 4.5
+- = 13 , ++ = 10 , -- = 2 , S/B = 0.453444 +/- 0.692369 , Acc = 0.811146
****************
Run 4
********************
**************** Numbers for North arm ********************
******* W. cut1, low mass = 1.5 to 2.4
+- = 508 , ++ = 148 , -- = 265 , S/B = 0.282567 +/- 0.0869982 , Acc = 3.68786
******* W. cut2, low mass = 1.5 to 2.4
+- = 497 , ++ = 144 , -- = 262 , S/B = 0.279365 +/- 0.0877311 , Acc = 3.61152
******* W. cut1, high mass >= 4.5
+- = 18 , ++ = 5 , -- = 13 , S/B = 0.116313 +/- 0.394339 , Acc = 0.312581
******* W. cut2, high mass >= 4.5
+- = 18 , ++ = 5 , -- = 12 , S/B = 0.161895 +/- 0.413068 , Acc = 0.423941
**************** Numbers for South arm ********************
******* W. cut1, low mass = 1.5 to 2.4
+- = 720 , ++ = 192 , -- = 417 , S/B = 0.272283 +/- 0.0729818 , Acc = 4.22676
******* W. cut2, low mass = 1.5 to 2.4
+- = 714 , ++ = 189 , -- = 412 , S/B = 0.279348 +/- 0.0738274 , Acc = 4.29925
******* W. cut1, high mass >= 4.5
+- = 21 , ++ = 7 , -- = 10 , S/B = 0.25499 +/- 0.413068 , Acc = 0.692166
******* W. cut2, high mass >= 4.5
+- = 21 , ++ = 7 , -- = 10 , S/B = 0.25499 +/- 0.413068 , Acc = 0.692166
One -- dimuon loss at high mass in North due to idquad cut!
Slide 10.
Vertex distributions for the Run 3 data (with id quad cut).
Slide 11.
Vertex distributions for the Run 4 data (with id quad cut).
Slide 12.