RQMD: p C ? ? X at T=3.2 and 5.13 GeV

1
RQMD pC ? ? X at T3.2 and
5.13 GeV

• Sergey Kiselev, ITEP Moscow
• Acceptance
• Input info
• Particle multiplicities
• Initial p0 spectra
• ? multiplicity
• ? spectra
• p0 spectra
• ? from p0
• ?R?? distributions
• M?? distributions

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Acceptance (set-up 80x80 cm2)
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Input info

• RQMD4.12 generator
• 105 min. bias pC events as at T3.2 and 5.13 GeV
• detector 80x80 cm2 at 250 cm from the target,
  ? 10 - 190
• Only ? from p0 will be analyzed
• Low momentum cut 400 MeV/c.
• Energy resolution 6/vE
• Space resolution cell size 10x10 cm2 ? momentum
  is matched to the center of a cell
• Trigger p? gt 0.4 GeV/c

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Particle multiplicities
// GEANT numbers of particles //
1. gamma 13. n0 25. n0
// 2. e 14. p
26. Lambda0 // 3. e- 15.
p- 27. Sigma- // 4.
neutrino 16. K_S0 28. Sigma0 //
5. mu 17. eta 29. Sigma
// 6. mu- 18. Lambda 30.
Xi0 // 7. pi0 19.
Sigma 31. Xi // 8. pi
20. Sigma0 32. Omega // 9.
pi- 21. Sigma- 33. omega
// 10. K_L0 22. Xi0 34. phi
// 11. K 23. Xi_
35. D // 12. K-
24. Omega- 36. D-

• 5.14 GeV

• 3.2 GeV

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Initial p0 spectra

• 3.2 GeV

• 5.13 GeV

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? multiplicity

• 3.2 GeV

• 5.13 GeV

2 events with gt 0 ?, 0.2 with gt 1 ?
5 events with gt 0 ?, 1 with gt 1 ?
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? spectra

• 3.2 GeV

• 5.13 GeV

excess over ? from p0 due to events with 1 ?
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p0 spectra

• 3.2 GeV

• 5.13 GeV

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? from p0

• 3.2 GeV

• 5.13 GeV

one can choose the trigger value
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?R?? distribution

• 3.2 GeV

• 5.13 GeV

More than 3 cells between ??
More than 2 cells between ??
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?R?? distribution vs P

• 3.2 GeV

• 5.13 GeV

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M?? distribution

• 3.2 GeV

• 5.13 GeV

width of the signal 20 MeV
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M?? at 3.2 GeV

• space resolution only

• space E resolution

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M?? at 5.13 GeV

• space resolution only

• space E resolution

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Conclusions

• Detector position (250 cm from the target, ?10 -
  190) is reasonable to measure p0 in the reactions
  pC at T3.2 and 5.13 GeV
• More than 2-3 cell size between ??
• Background in M?? is small