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 Energy  Office of Science Grant No.:DE-FG02-07ER41528 Jefferson Lab Hall C Users Meeting 31st January, 2009 1 1 1

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

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  = 0.72 – 0.78, for p,k, 3 3 3

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

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

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

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

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

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

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 = 1.115 GeV/c2 Mass of Λ is MΛ = [EΛ2 - PΛ2 ]1/2 MΣ = 1.119 GeV/c2 10

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

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

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 : 9.7 Q2=3.0 GeV2 : 6.4 Red – SIMC Blue – Data Q2 Q2 13 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 W = Centre of Mass Energy w w SIMC Λ + Σ Data & Data Red – SIMC Blue – Data w w 14 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 t = Mandelstam Variable t t SIMC Λ + Σ Data & Data Red – SIMC Blue – Data t t 15 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 ϕpq= Angle Between Reaction Plane & Scattering Plane ϕpq ϕpq SIMC Λ + Σ Data & Data Red – SIMC Blue – Data ϕpq ϕpq 16 16

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

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

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

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

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

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

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

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 0.4 - 0.7 Particle ID scale(%) total(%)‏ point-to-point (%)‏ Item 5.4

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 )

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

Thank You 27

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