SCALING LAW in single charged pion electroproduction

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SCALING LAW in single charged pion
electroproduction

• ?p ?pn

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KINEMATIC RANGE
NO CUT
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PARTICLE IDENTIFICATION

• 1. Electron PID as same as resonance region
  analysis.
• 2. As same as electron, pion fiducial cuts were
  applied .
• 3. Mass between pion and proton can be separated
• upto 2GeV of momentum
• 4. Assume that proton contamination is small at
  high momentum
• And, it does not contribute miss mass peak
• 0.5lt MMx (cut) lt 1.1GeV , W gt 1.7GeV
• 5. Background subtraction under the missing mass
  peak
• gaussian miss mass peak
• 2nd order of polynomial Breit-Wigner for
  the Delta

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ACCEPTANCE TABLE

• Event was weighted with w1/(epsGEO x epsSIM)

• Kinematic variable in Accep. Table (Q2, Xbj,
  -t, phicm)

• Kinematic variable Range width

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ACCEPTANCE CALCULATION

• Check up with ACC table by plotting

• Remove the bin contains gt10 of stat. error of ACC

(Q2, Xbj, -t, ) Integrated over all Fp
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RADIATIVE CORRECTION

• Check up with FRAD table by Simulation data

• Remove the bin contains gt10 of stat. error of
  FRAD.

(Q2, Xbj, -t, ) Integrated over all Fp
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WHAT TO DO ?

• Additional tasks
• Background subtraction under the neutron peak
• Need to be measured neutron in EC (on going)

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MISSING MASS
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ACCESSIBLE W
W 1.52, 1.64, 1.67, 179, 1.82, 1.96, 1.99, 2.2
2.43, 2.45, 2.47, 2.7, 2.73, 2.81, 3.12 GeV
Only 26bins are available.!
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WHAT TO DO ?

• Additional tasks
• All Correction factors are small enough to be
  negligible
• gt 480 bins are available.

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my Preliminary Result
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-t channel dependenceds/dt vs. t
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Q2 2.05, Xbj0.49, -t2.3 ACC
0.02735.7 This bin slightly lower ACC than
neighbors (15.9)
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Q2 2.35, Xbj0.49, -t1.75 ACC
0.07093.4 This bin slightly lower ACC than
neighbors (18.5)
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W dependences7ds/dt vs. W
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Saclay Group Preliminary Result
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Units µb
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ltWgt 2.0 GeV
ltWgt 2.45 GeV