Update of f1020 e16 Analysis

1
Update of f(1020) e1-6 Analysis

• Joe Santoro
• CLAS Collaboration Meeting
• June 20, 2006

2
f electroproduction
3
f electroproduction
ep?epf?epK(K-)
e1a/e1b E 4.2 GeV, Q2 0.7 - 2.2 GeV2
e1-6a E 5.75 GeV Q2 1.7 - 3.8 GeV2
Q2 (GeV2)
Q2 (GeV2)
Q²
W (GeV)
W (GeV)
4
e1-6 Experiment _at_ CLAS

• 5.75 GeV Beam
• 21 mC of Accumulated Charge on
• a Proton Target
• ep ?epf?K(K-)

Drift Chambers
TOF
Cherenkov
Electromagnetic Calorimeter
5
Electron Selection
Z-Vertex
E/p vs P EC energy
Electron Fiducial cuts
Number of photoelectrons
6
Hadron Selection
K- MM Cut
Kaons before fiducial cuts
Kaons after fiducial cuts
MMepK vs IMkk
7
6-D Acceptance Correction
8
6-D Acceptance Correction
9
Radiative Corrections
EXCLURAD was used to obtain corrections in
Q2,W,F, and COS(q)CM bins
10
f yields

• Collected 4x
• number of fs as
• previous CLAS
• measurement and
• in a higher Q2 range

Nf792 94
IMKK (GeV)
11
Differential Cross Section in t
t 0.2 GeV2
t 0.6 GeV2
t 1.0 GeV2
t 1.4 GeV2
t 1.8 GeV2
t 2.2 GeV2
t 3.2 GeV2
t 2.6 GeV2
K K- Invariant Mass (GeV)
12
VMD Model Comparison
VMD predicts
Lukashin, et. al.
13
Total Cross Sections s(Q2)
Q2 1.7 GeV2
Q2 1.9 GeV2
Q2 2.4 GeV2
Q2 2.1 GeV2
f yields in six Q2 bins
Q2 2.8 GeV2
Q2 3.4 GeV2
K K- Invariant Mass (GeV)
14
JML Model Comparison
Reggon (Pomeron) 2-gluon Exchange Model
ltWgt2.4 GeV
15
Comparison to World Data
16
Differential Cross Section in F
SCHC Conserved
17
Fits and extraction of
18
GPD Discussion

• GPDs predict as

R
Q2 (GeV2)
19
Summary

• Kinematic Ranges 1.6 Q2 3.8, 0.0 t -3.6,
  
• 2.0 W 3.0
• Total f yields 4x statistics of previous CLAS
  result
• Differential cross section in t VMD bf
  measured decreasing
• Total cross sections in Q2 Comparison to JML
  model
• Angular Distributions measured
• GPD-related results measured ltRgt which shows
  expected
• trend, but no model calculation for comparison

20
To Do
CLAS analysis note is under review

• Quantify systematic errors
• Write paper ?