Color Transparency

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Kaons Propagation Through Nuclei
Nuruzzaman Mississippi State University
Medium Energy Physics Group Advisor Dr.Dipangkar
Dutta (http//ra.msstate.edu/dd285/mep.html)?
This work is sponsored  by the Department of Energ
y  Office of Science Grant No.DE-FG02-07ER41528
Jefferson Lab Hall C Users Meeting 31st January,
2009
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Outline

• Nuclear Transparency
• Nuclear Transparency with Pions Kaons
• Analysis
• Preliminary Results

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Nuclear Transparency
Ratio of cross-sections for exclusive processes
from nuclei to those from nucleons is termed as
Nuclear Transparency
Free (nucleon) cross-section
Nuclear cross-section
.?.
T Aa-1
parameterized as
Experimentally ? 0.72 0.78, for p,k,??
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Outline

• Nuclear Transparency
• Nuclear Transparency with Pions Kaons
• Analysis
• Preliminary Results

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Transparency Experiment with
Pions
Kaons
/
Experiment ran in July 04 and December 04 at
Jefferson Lab
JLab Experiment E01-107 A(e,e? ??)
Spokespersons D. Dutta Rolf Ent
Data collected on LH2, LD2, 12C, 63Cu, and 197Au
at Pp of 2.8, 3.2, 3.4, 4.0 and 4.4 (GeV/c) Q2
of 1.1, 2.15, 3.0, 4.0 and 4.7 (GeV/c)2
The experiment was measuring pion transparency,
however one  gets kaons along with
pions during data collection because kaons fall  w
ithin the coincidence window.
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Hall C
HMS
SOS
G0
HMS- High Momentum Spectrometer SOS- Short Orbit
Spectrometer
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Outline

• Nuclear Transparency
• Nuclear Transparency with Pions Kaons
• Analysis
• Preliminary Results

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JLab Experiment E01-107
Typical coincidence time spectrum showing the
different particles detected
p
K
p
Coincidence Time (ns)
Coincidence time  Time taken by electron to
reach SOS - Time taken by hadrons to reach HMS
(within a 30ns window)?
Kaon transparency from electro-production has
never been measured before!!!
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Particle Identification in the HMS
Gas Cerenkov   (Perflurobutane at 1
atm.)? (for pi/k separation)?
Aerogel Cherenkov  (Aerogel2 of
n  1.015)  (for k/p separation)?
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Particle Identification in the HMS
Reactions
Energy Momentum Conservation
Ee Mp Ee? EK E? Pe 0 Pe PK
P?
M? 1.115 GeV/c2
Mass of ? is M? E?2 - P?2 1/2
MS 1.119 GeV/c2
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Before After Application of Constraints on
Kaon(Liquid Hydrogen) Data
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Experimental Simulation SIMC
Ingredients of SIMC1. Realistic Models of the m
agnetic spectrometers including multiple scatteri
ng and energy loss in all intervening material enc
ountered by the particles.2. Decay of kaons in 
flight, and radiative corrections for all particl
es.3. Model of the electro production of kaons f
rom free protons4. For heavier targets the free
proton model is convoluted with a realistic spect
ral function for each target.   Spectral function
  probability of finding a proton inside the nucl
eus with a certain energy and momentum.
Transparency to be extracted as
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Comparison of Liquid Hydrogen Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
s  s (Q2, W, t,  ?pq)?
SIMC ?
SIMC S
Q2 Four Momentum Transferred Squared
Q2
Q2
The ratio of ?/S is determined from the LH2 data
SIMC ? S
Data
Data
Q21.1 GeV2 15.6 Q22.2 GeV2 9.7 Q23.0
GeV2 6.4
Red SIMC Blue Data
Q2
Q2
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Comparison of Liquid Hydrogen Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
s  s (Q2, W, t,  ?pq)?
SIMC ?
SIMC S
W Centre of Mass Energy
w
w
SIMC ? S
Data
Data
Red SIMC Blue Data
w
w
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Comparison of Liquid Hydrogen Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
s  s (Q2, W, t,  ?pq)?
SIMC ?
SIMC S
t Mandelstam Variable
t
t
SIMC ? S
Data
Data
Red SIMC Blue Data
t
t
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Comparison of Liquid Hydrogen Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
s  s (Q2, W, t,  ?pq)?
SIMC ?
SIMC S
?pq Angle Between Reaction Plane Scattering
Plane
?pq
?pq
SIMC ? S
Data
Data
Red SIMC Blue Data
?pq
?pq
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Before After Application of Constraints on
Kaon(Liquid Deuterium) Data
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Comparison of Liquid Deuterium Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
s  s (Q2, W, t,  ?pq)?
SIMC ?
SIMC S
Q2 Four Momentum Transferred
Squared
Q2
Q2
SIMC ? S
Data
Data
The ratios of ?/S obtained from LH2 data are used
to add the ?-SIMC and S-SIMC yields
Red SIMC Blue Data
Q2
Q2
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Comparison of Liquid Deuterium Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
s  s (Q2, W, t,  ?pq)?
W Centre of Mass Energy
w
w
Red SIMC Blue Data
w
w
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Comparison of Liquid Deuterium Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
s  s (Q2, W, t,  ?pq)?
t
t
t Mandelstam Variable
Red SIMC Blue Data
t
t
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Comparison of Liquid Deuterium Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
SIMC ?
SIMC S
s  s (Q2, W, t,  ?pq)?
?pq Angle Between Reaction Plane Scattering
Plane
?pq
?pq
SIMC ? S
Data
Data
Red SIMC Blue Data
?pq
?pq
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Comparison of Data vs Simulation(SIMC)applying
all constraints for Other Targets
All particle identification and acceptance constra
ints applied
s  s (Q2, W, t,  ?pq)?
Carbon
Copper
SIMC ? S
Data
Q2
Q2
Gold
Q2 Four Momentum
Transferred Squared
Red SIMC Blue Data
Q2
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Outline

• Nuclear Transparency
• Nuclear Transparency with Pions Kaons
• Analysis
• Preliminary Results

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Systematic Uncertainties of E01107
5.4
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Nuclear Transparency vs Q2
Cu, C, LD2 are shifted by -0.05,0.05,-0.10 in Q2
respectively
Preliminary Result
LD2 - Black
Carbon - Red
Transparency
Copper - Green
Gold - Blue
Q2 ( GeV/c2 )
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Analysis Plan

• Determine the model dependent uncertainty
• Compare with theoretical calculations(Please
  contact your favorite
• theorist )
• Write paper publish results

This work is sponsored  by the Department of Energ
y  Office of Science Grant No. DE-FG02-07ER41528
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Thank You
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Comparison of Liquid Deuterium Data vs
Simulation(SIMC)applying all constraints
All particle identification and acceptance constra
ints applied
SIMC ?
SIMC S
s  s (Q2, W, t, phipq)?
Missing Mass
missing mass
missing mass
SIMC ? S
Data
Data
Red SIMC Blue Data
missing mass
missing mass