FROST: Status of gp K L analysis

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FROST Status of gp -gt KL analysis

• Liam Casey
• Catholic University of America
• Adviser Dr. Franz Klein

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Particle Identification

• Protons, pions, and kaons are identified by beta
  and momentum cuts.
• Kaon region may overlap with misidentified
  protons and pions.
• Bad timing information may also give false kaon
  identification at low momentum.

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Missing Mass Plots Finding L
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Missing Mass Plots Finding L (cont)
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Momentum plotted against Missing Mass (1)

• In the lower energy regions, a L signal is
  visible when missing mass is plotted.
• There is additionally a peculiar sloping line
  passing through the signal region, which most
  likely indicates misidentified kaons.

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Momentum plotted against Missing Mass (2)

• The L signal fades for higher photon energies,
  while the sloping line remains.

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Polarization Observable E Comparison to Model
Predictions (2.478 GeV Beam)

• Appears to show some level of agreement with SAID
  data.
• Higher cos q bins are more suspect due to high
  background contamination.
• For full asymmetry, Ptarg 0.8, Pel 0.85 are
  taken as averages.

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Polarization Observable E More Energy ranges
(2.478 GeV Beam)
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Conclusions and Further Work

• All results are extremely preliminary, but first
  measurements of E indicate some qualitative
  agreement with SAID PWA in more trustworthy
  regions (those not dominated by heavy
  background).
• Energy loss corrections need to be added without
  losing all the lambdas.
• Background subtraction
• Measurements of other polarization observables