# Presentation: 430603

## Kaons Propagation Through Nuclei

**Nuruzzaman**
**Mississippi State University**

**This work is sponsored**
** ****by the Department of Energy **
**Office of Science**
**Grant No.:DE-FG02-07ER41528**

**Jefferson Lab Hall C Users Meeting**
**31****st**** January, 2009**

**Medium Energy Physics Group**
**Advisor: Dr.Dipangkar Dutta **
**(http://ra.msstate.edu/~dd285/mep.html)****‏**

## Outline

**Nuclear Transparency **
**Nuclear Transparency with Pions & Kaons**
**Analysis**
**Preliminary ****Results**

## 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**

**Experimentally   ********  =  0.72 – 0.78, for  p,k,************  **

**parameterized as =**

**. ̇****.****  **

**T= A****α****-1**

## Outline

**Nuclear Transparency **
**Nuclear Transparency with Pions & Kaons**
**Analysis**
**Preliminary ****Results**

## Transparency Experiment with

**Experiment ran in July `04 and December `04 at Jefferson Lab **

**Data collected on  ****LH****2****, LD****2****, ****12****C, ****63****Cu, and ****197****Au**** at **
**P****π**** of ****2.8****, 3.2, 3.4, 4.0 and 4.4 (GeV/c) **
**Q****2**** of 1.1, 2.15, 3.0, 4.0 and 4.7 (GeV/c)****2 **** **

**JLab  Experiment  E01-107:  A(e,e**** ́**** ************)**

**The experiment was measuring pion transparency, however one **
**gets kaons along with pions during data collection because kaons fall **
**within the coincidence window.**

**Spokespersons : D. Dutta & Rolf Ent**

*Pions*

*Kaons*

*/*

**Notes:**
Out going scatered particle has energy of ~100MeV

## Hall C

**HMS- High Momentum Spectrometer**
**SOS- Short Orbit Spectrometer**

**SOS**

**HMS**

**G0**

## Outline

**Nuclear Transparency **
**Nuclear Transparency with Pions & Kaons**
**Analysis**
**Preliminary ****Results**

## JLab Experiment E01-107 

*JLab Experiment E01-107 *

**Typical coincidence time spectrum showing the different particles detected**

**Kaon transparency from electro-production has never been measured before!!!**

**Coincidence time = Time taken by electron to reach SOS - Time taken by hadrons to reach HMS (within a 30ns window)****‏**

**π**

**K****+**

**p**

**Coincidence Time (ns)**

**Notes:**
The small peaks are due to beam bucket comming every 2 nS and giving random coincidences

## 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)****‏**

## Particle Identification in the HMS

*Particle Identification in the HMS*

**E****e ****+ M****p**** = E****e****׳**** ****+ E****K+**** +E****Λ **** **
**P****e**** + 0 = P****e’**** + P****K+**** + P****Λ**** **

**Energy & Momentum Conservation**

**Mass of ****Λ**** is ****M****Λ**** ****=  [****E****Λ****2**** - P****Λ****2**** ]****1/2**

**Reactions**

**M****Λ **** = 1.115 GeV/c****2**

**M****Σ **** = 1.119 GeV/c****2**

## Before & After Application of Constraints on Kaon(Liquid Hydrogen) Data

*Before & After Application of Constraints on Kaon(Liquid Hydrogen) Data*

## 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**

## σ = σ (Q2, W, t,  φpq)‏

*Comparison of Liquid Hydrogen Data vs Simulation(SIMC)applying all constraints*

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

**Q****2**** = Four Momentum**
**Transferred Squared**

**         ****Q2**

**         ****Q2**

**         ****Q2**

**         ****Q2**

**SIMC ****Λ**

**SIMC ****Σ**

**Data**

**SIMC ****Λ**** ****+**** ****Σ**

**&**
**Data**

**The ratio of ****Λ****/****Σ**** is determined from the LH2 data**

**Q****2****=1.1 GeV****2**** : 15.6 Q****2****=2.2 GeV****2**** :  9.7 ****Q****2****=3.0 GeV****2**** :  6.4 **

## σ = σ (Q2, W, t,  φpq)‏

*Comparison of Liquid Hydrogen Data vs Simulation(SIMC)applying all constraints*

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

**W = Centre of**
**Mass Energy**

**         ****w**

**         ****w**

**         ****w**

**         ****w**

**SIMC ****Λ**

**SIMC ****Σ**

**Data**

**SIMC ****Λ**** ****+**** ****Σ**

**&**
**Data**

## σ = σ (Q2, W, t,  φpq)‏

*Comparison of Liquid Hydrogen Data vs Simulation(SIMC)applying all constraints*

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

** ****t ****= Mandelstam Variable **

**        ****t**

**        ****t**

**        ****t**

**        ****t**

**SIMC ****Λ**

**SIMC ****Σ**

**Data**

**SIMC ****Λ**** ****+**** ****Σ**

**&**
**Data**

## σ = σ (Q2, W, t,  φpq)‏

*Comparison of Liquid Hydrogen Data vs Simulation(SIMC)applying all constraints*

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

**φ****pq****= Angle Between**
**Reaction Plane &**
**Scattering Plane**

**         ****φ****pq**

**SIMC ****Λ**

**SIMC ****Σ**

**Data**

**SIMC ****Λ**** ****+**** ****Σ**

**&**
**Data**

**         ****φ****pq**

**         ****φ****pq**

**         ****φ****pq**

## Before & After Application of Constraints on Kaon(Liquid Deuterium) Data

*Before & After Application of Constraints on Kaon(Liquid Deuterium) Data*

## σ = σ (Q2, W, t,  φpq)‏

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

*Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints*

**Q****2**** = Four Momentum **
**         ****Transferred**
**         ****Squared**

**         ****Q2**

**         ****Q2**

**         ****Q2**

**         ****Q2**

**SIMC ****Λ**

**SIMC ****Σ**

**Data**

**SIMC ****Λ**** ****+**** ****Σ**

**&**
**Data**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

**The ratios of ****Λ****/****Σ**** obtained from LH2 data are used to add the ****Λ****-SIMC and ****Σ****-SIMC yields**

## σ = σ (Q2, W, t,  φpq)‏

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

*Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints*

**W = Centre of Mass Energy**

**         ****w**

**         ****w**

**         ****w**

**         ****w**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

## σ = σ (Q2, W, t,  φpq)‏

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

*Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints*

**t ****= Mandelstam **
**      ****Variable **

**        ****t**

**        ****t**

**        ****t**

**        ****t**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

## σ = σ (Q2, W, t,  φpq)‏

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

*Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints*

**SIMC ****Λ**

**SIMC ****Σ**

**Data**

**SIMC ****Λ**** ****+**** ****Σ**

**&**
**Data**

**φ****pq****= Angle Between**
**Reaction Plane &**
**Scattering Plane**

**           ****φ****pq**

**           ****φ****pq**

**           ****φ****pq**

**           ****φ****pq**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

## σ = σ (Q2, W, t,  φpq)‏

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

*Comparison of Data vs Simulation(SIMC)applying all constraints for Other Targets*

**Q****2**** = Four **
**         ****Momentum **
**         ****Transferred**
**         ****Squared**

**         ****Q2**

**         ****Q2**

**         ****Q2**

**SIMC ****Λ**** ****+**** ****Σ**

**&**
**Data**

**σ**** = ****σ**** (****Q****2****, ****W****, t, **** φ****pq****)****‏**

**Carbon**

**Copper**

**Gold**

## Outline

**Nuclear Transparency **
**Nuclear Transparency with Pions & Kaons**
**Analysis**
**Preliminary ****Results**

## Systematic Uncertainties of E01107

**5.4**

## Nuclear Transparency vs Q2

**LD2 - Black**

**Carbon - Red**

**Copper - Green**

**Gold - Blue**

*Nuclear Transparency *vs* Q**2*

**Q****2**** ( GeV/c****2**** )**

**Preliminary Result**

**Cu, C, LD2 are shifted by -0.05,0.05,-0.10 in Q2 respectively **

## 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**

## Thank You

## σ = σ (Q2, W, t, phipq)‏

**Red**** – SIMC**
**Blue ****– Data **

**All particle identification and acceptance constraints applied**

**σ**** = ****σ**** (****Q****2****, ****W****, t, phipq)****‏**

*Comparison of Liquid Deuterium Data vs Simulation(SIMC)applying all constraints*

**Missing Mass**

**missing mass**

**missing mass**

**missing mass**

**missing mass**

**SIMC ****Λ**

**SIMC ****Σ**

**Data**

**SIMC ****Λ**** ****+**** ****Σ**

**&**
**Data**