1. Kaons Propagation Through Nuclei
Nuruzzaman
Mississippi State University
Medium Energy Physics Group
Advisor: Dr.Dipangkar Dutta (
This work is sponsored
 by the Department of Energy 
Office of Science
Grant No.:DE-FG02-07ER41528
Jefferson Lab Hall C Users Meeting
31st January, 2009 1 1 1

2. Outline Nuclear Transparency Nuclear Transparency with Pions & Kaons
Analysis
Preliminary Results 2 2 2

3. 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= Aα-1
parameterized as =
Experimentally  = – 0.78, for p,k, 3 3 3

4. Outline Nuclear Transparency Nuclear Transparency with Pions & Kaons
Analysis
Preliminary Results 4 4 4

5. 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
Pπ 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
Out going scatered particle has energy of ~100MeV
The experiment was measuring pion transparency, however one 
gets kaons along with pions during data collection because kaons fall 
within the coincidence window. 5 5 5

6. Hall C G0 HMS- High Momentum Spectrometer
SOS G0
HMS- High Momentum Spectrometer
SOS- Short Orbit Spectrometer 6

7. Outline Nuclear Transparency Nuclear Transparency with Pions & Kaons
Analysis
Preliminary Results 7 7 7

8. JLab Experiment E01-107 π K+ p
Typical coincidence time spectrum showing the different particles detected π K+ p
The small peaks are due to beam bucket comming every 2 nS and giving random coincidences
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!!! 8 8 8

9. Particle Identification in the HMS
Aerogel Cherenkov 
(Aerogel2 of n = 1.015) 
(for k/p separation)‏
Gas Cerenkov  
(Perflurobutane at 1 atm.)‏
(for pi/k separation)‏ 9 9 9

10. Energy & Momentum Conservation
Particle Identification in the HMS
e + p e’+K+ + Λ
e + A e’+K+ + Λ + X
Reactions e A Λ  e´
missing mass
A-1
Energy & Momentum Conservation
Ee + Mp = Ee׳ + EK+ +EΛ
Pe + 0 = Pe’ + PK+ + PΛ
MΛ = GeV/c2
Mass of Λ is MΛ = [EΛ2 - PΛ2 ]1/2
MΣ = GeV/c2 10

11. Kaons after application of all constraints for H target
Before & After Application of Constraints on Kaon(Liquid Hydrogen) Data
Pions, Protons, Kaons (in coincidence time vs missing mass ) using a loose Constraints
Pions
Kaons
Protons
MΛ= 1.115
MΣ= 1.119
Missing Mass:
1.10<Mx <1.15 for Λ,
1.17<Mx <1.22 for Σ
Coincidence Time:
abs(cointime+58.63)<0.26
Gas Cherenkov:
SOS, N(p.e)>1; HMS, N(p.e)<1
Aerogel Cherenkov:
HMS, N(p.e)<0
Other acceptances
Hsyptar, hsxptar, hsdelta, ssdelta
Kaons after application of all constraints for H target 11

12. Experimental Simulation “SIMC”
Ingredients of SIMC: 1. Realistic Models of the magnetic spectrometers including multiple  scattering and energy loss in all intervening material encountered by the  particles. 2. Decay of kaons in flight, and radiative corrections for all  particles. 3. Model of the electro production of kaons from free protons 4. For heavier targets the free proton model is convoluted with a realistic  spectral function for each target.   
Spectral function = probability of finding a proton inside the nucleus with a certain energy and momentum.
Transparency to be extracted as 12

13. All particle identification and acceptance constraints applied
Comparison of Liquid Hydrogen Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
σ = σ (Q2, W, t,  ϕpq)‏
SIMC Λ
SIMC Σ
Q2 = Four Momentum
Transferred Squared Q2 Q2
The ratio of Λ/Σ is determined from the LH2 data
SIMC Λ + Σ
Data
&
Data
Q2=1.1 GeV2 : 15.6 Q2=2.2 GeV2 : Q2=3.0 GeV2 : 6.4
Red – SIMC
Blue – Data Q2 Q2 13 13

14. All particle identification and acceptance constraints applied
Comparison of Liquid Hydrogen Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
σ = σ (Q2, W, t,  ϕpq)‏
SIMC Λ
SIMC Σ
W = Centre of
Mass Energy w w
SIMC Λ + Σ
Data
&
Data
Red – SIMC
Blue – Data w w 14 14

15. All particle identification and acceptance constraints applied
Comparison of Liquid Hydrogen Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
σ = σ (Q2, W, t,  ϕpq)‏
SIMC Λ
SIMC Σ
t = Mandelstam Variable t t
SIMC Λ + Σ
Data
&
Data
Red – SIMC
Blue – Data t t 15 15

16. All particle identification and acceptance constraints applied
Comparison of Liquid Hydrogen Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
σ = σ (Q2, W, t,  ϕpq)‏
SIMC Λ
SIMC Σ
ϕpq= Angle Between
Reaction Plane &
Scattering Plane
ϕpq
ϕpq
SIMC Λ + Σ
Data
&
Data
Red – SIMC
Blue – Data
ϕpq
ϕpq 16 16

17. Kaons separated after application of all constraints on LD target
Before & After Application of Constraints on Kaon(Liquid Deuterium) Data
Kaons separated after application of all constraints on LD target
Missing Mass:
1.09<Mx <1.22
Coincidence Time:
abs(cointime+58.63)<0.26
Gas Cherenkov:
SOS, N(p.e)>1; HMS, N(p.e)<1
Aerogel Cherenkov:
HMS, N(p.e)<0
Other acceptances
Hsyptar, hsxptar, hsdelta, ssdelta
Pions, Protons & Kaons before application of all constraints for LD target 17 17

18. All particle identification and acceptance constraints applied
Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
σ = σ (Q2, W, t,  ϕpq)‏
SIMC Λ
SIMC Σ
Q2 = Four Momentum
Transferred
Squared Q2 Q2
SIMC Λ + Σ
Data
&
Data
The ratios of Λ/Σ obtained from LH2 data are used to add the Λ-SIMC and Σ-SIMC yields
Red – SIMC
Blue – Data Q2 Q2 18 18

19. All particle identification and acceptance constraints applied
Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
SIMC Λ
SIMC Σ
Data
SIMC Λ + Σ
&
σ = σ (Q2, W, t,  ϕpq)‏
W = Centre of Mass Energy w w
Red – SIMC
Blue – Data w w 19 19

20. All particle identification and acceptance constraints applied
Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
SIMC Λ
SIMC Σ
Data
SIMC Λ + Σ
&
σ = σ (Q2, W, t,  ϕpq)‏ t t
t = Mandelstam
Variable
Red – SIMC
Blue – Data t t 20 20

21. All particle identification and acceptance constraints applied
Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
SIMC Λ
SIMC Σ
σ = σ (Q2, W, t,  ϕpq)‏
ϕpq= Angle Between
Reaction Plane &
Scattering Plane
ϕpq
ϕpq
SIMC Λ + Σ
Data
&
Data
Red – SIMC
Blue – Data
ϕpq
ϕpq 21 21

22. All particle identification and acceptance constraints applied
Comparison of Data vs Simulation(SIMC)applying all constraints for Other Targets
All particle identification and acceptance constraints applied
σ = σ (Q2, W, t,  ϕpq)‏
Carbon
Copper
SIMC Λ + Σ
&
Data Q2 Q2
Gold
Q2 = Four
Momentum
Transferred
Squared
Red – SIMC
Blue – Data Q2 22 22

23. Outline Nuclear Transparency Nuclear Transparency with Pions & Kaons
Analysis
Preliminary Results 23 23 23

24. Systematic Uncertainties of E01107
3.9
3.8
TOTAL
2.0
1.0
Spectral Function
Iteration
0.5
Acceptance
collimator
Radiative Corrections
Pauli Blocking
Pion Decay
2.5
Cut dependence
0.1
Beam Energy
Pion Absorption
Tracking(HMS+SOS)‏
Dead time correction
0.7
Trigger(HMS+SOS)‏
Coin blocking
Target thickness
0.3
Charge
Particle ID
scale(%) total(%)‏
point-to-point (%)‏
Item
5.4

25. 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 )

26. by the Department of Energy
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 Energy 
Office of Science
Grant No.: DE-FG02-07ER41528 26 26 26

27. Thank You 27

28. All particle identification and acceptance constraints applied
Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints
All particle identification and acceptance constraints applied
SIMC Λ
SIMC Σ
σ = σ (Q2, W, t, phipq)‏
Missing Mass
missing mass
missing mass
SIMC Λ + Σ
Data
&
Data
Red – SIMC
Blue – Data
missing mass
missing mass 28 28