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Measurement of B (D +   + )

Measurement of B (D +   + ). Sadia Khalil & Sheldon Stone Syracuse University 08/28/2007. Method. Look for D - D +   +  

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Measurement of B (D +   + )

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  1. Measurement of B(D+ + ) Sadia Khalil & Sheldon Stone Syracuse University 08/28/2007

  2. Method Look for D-D+ +  K+- - K+- - 0 Ks - Ks- - + Ks- 0 K+ K-- Signal Tags

  3. Data 44 (174 pb-1)

  4. Mbc distributions Data44

  5. Number of Tags Data 44

  6. Signal Events = 25

  7. Comparison

  8. Comparison

  9. Data 31-44 (598.7 pb-1)

  10. Mbc distributions Data31-44

  11. Mbc distributions Data31-44(log scale) D+  Ks+ D+  K- ++ D+  K- ++ 0 D+  Ks+0 D+  Ks++ + D+  K- K++

  12. Signal Events = 91@599 pb -1 MM2 (GeV2)

  13. Number of Tags(599 pb-1) After a correction of 1.5±0.64 % based on the fact it is easier to find tags in +  events than in generic decays, the total # of tags is 347297±677±2223

  14. Background Evaluation

  15. Background from +0 and+(+) in signal region +0:MM2 peaks at 0.02 well within µ+ resolution of 2.5 +  : MM2 peaks at 0.05 ,therefore the tail contributes • Generate 30,000 events of signal MC of +0 and + events respectively • Use the same code as is used to determine + branching fraction • Find the total tags within 3 of mbc , count the +0 events in signal region • Count the number of events within the signal region of +, get the efficiency of +0/ +and find the number of background events • Fit the distribution and get the efficiency of +0/+and the shape • Compare the background within the signal region of + from the fit of data and from mere counting.

  16. Decay Table of D+ modes Run number : 205691 *mcgenerator release : 20070329_MCGEN *mcpass2 release : 20041104_MCP2_1 *https://wiki.lepp.cornell.edu/lepp/bin/view/CLEO/Private/SW/CLEOcSignalMC

  17. Mbc Distribution of D- modes for MC of D+→+0

  18. MM2 of + 0 87 events

  19. Number of Tags (+0 MC)

  20. +0 backgrounds within [-0.05, 0.05] of + signal ε+ 0 =Nsig/NTag = 87/11180 =0.00778 ± 0.00084 • = 1.31 ± 0.02 (CLEOc measurement) N+ 0(@281pb-1)= 1.638 ± 0.176(stat)±0.252(syst) CBX 05-23 result = 1.40 ± 0.18 ± 0.22 • N+ 0(@600 pb-1) = 3.55 ± 0.38(stat) ± 0.55(syst)

  21. Mbc Distribution of D- modes for MC of D+→+

  22. MM2 of + 

  23. Number of Tags (+  MC)

  24. From counting the events in MM2 plot of +  within -0.05 to 0.05 ε = 972/11342 = 0.085 No of +  events = 3.77 From the fit of MM2 of+ ε+ = 0.40 ± 0.007 No of +  events = r = (0.29 * ε)/ ε = 0.166±0.004 Next how did I to find it?

  25. Mbc Distribution of D+ modes for MC of D+→+

  26. Number of Tags (+  MC)

  27. MM2 of +  ε = 0.7±0.01

  28. MM2 of + (Data) Need to get shape of this source

  29. Backup plots

  30. E Sidebands Data44

  31. E Sidebands Data31-44

  32. MM2 of +0 for each mode D+  K- ++ 0 D+  K- ++ D+  Ks+ D+  Ks+0 D+  Ks++ + D+  K- K++

  33. MM2 of + for each mode D+  K- ++ 0 D+  K- ++ D+  Ks+ D+  Ks+0 D+  Ks++ + D+  K- K++

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