# Presentation: 645348

## Search for P and CP Violation in Heavy Ion Interactions with the STAR TPC Detector

- Vasily Dzhordzhadze
- STAR Analysis Meeting, BNL
- October 16, 2007

## 
Search for the CP violation in Heavy Ion Collisions predicted by D. Kharzeev [1] :      
   We are looking for a charge asymmetry relative to the Reaction Plane in HIC
We are using specific angular correlations, the method developed by S. Voloshin [2] .

  [1] D. Kharzeev, hep-ph/0406125 (2004)
  [2] S. Voloshin,   PRC 70 057901 (2004)

- Search for the CP violation in Heavy Ion Collisions predicted by D. Kharzeev [1] :
-    We are looking for a charge asymmetry relative to the Reaction Plane in HIC
- We are using specific angular correlations, the method developed by S. Voloshin [2] .
-   [1] D. Kharzeev, hep-ph/0406125 (2004)
-   [2] S. Voloshin,   PRC 70 057901 (2004)

- Motivation

## Slide 3

## Analysis performed by Ilya Selyuzhenkov observed very significant effect of possible CP violation -> very exciting Physics
Independent Analysis performed by Vasily Dzhordzhadze is reported in this presentation
Both analysis get consistent results 
We found CP violation effects which needs further studies to determine the nature of the observed signals

- Independent Analysis performed by Vasily Dzhordzhadze is reported in this presentation
- Both analysis get consistent results
- We found CP violation effects which needs further studies to determine the nature of the observed signals

- Analysis

## Run 4 :  
 62  GeV:   13.4 M -> 8.3 M
200 GeV:  18.3 M -> 7.1  M (Reverse Field)
200 GeV:   5.4 M -> 4.4 M (Full Field)

Trigger cuts and Zvertex cuts, excluding 
Zvertex=0

-  62  GeV:   13.4 M -> 8.3 M
- 200 GeV:  18.3 M -> 7.1  M (Reverse Field)
- 200 GeV:   5.4 M -> 4.4 M (Full Field)
- Trigger cuts and Zvertex cuts, excluding
- Zvertex=0

- Statistics used in the Analysis

## Run 4, AuAu 62 GeV ||<0.9, EP (+-)

- Run 4, AuAu 62 GeV ||<0.9, EP (+-)

## Run 4, AuAu 200 GeV, RF, EP (+-)

## Run 4, AuAu 200 GeV ||<0.9, FF, EP (+-)

- Run 4, AuAu 200 GeV ||<0.9, FF, EP (+-)

## Run 4, AuAu 62 GeV ||<0.9, All EP

- Run 4, AuAu 62 GeV ||<0.9, All EP

## Run 4, AuAu 200 GeV ||<0.9,  All EP, RF

- Run 4, AuAu 200 GeV ||<0.9,  All EP, RF

## Run 4, AuAu 200 GeV ||<0.9, All EP (FF)

- Run 4, AuAu 200 GeV ||<0.9, All EP (FF)

## J. Dunlope, T. Hallman, M. Potekhin, Y. Semertzidis
Recommendations to check:
1. Agreement between two searches  (done)
2. Dependence on beam intensity      (done)
3. Dependence on Vertex position      (done)
4. Dependence on TPC Space charge
5. Dependence on TPC Pad efficiencies
6. Simulation study

- Recommendations to check:
- 1. Agreement between two searches  (done)
- 2. Dependence on beam intensity      (done)
- 3. Dependence on Vertex position      (done)
- 4. Dependence on TPC Space charge
- 5. Dependence on TPC Pad efficiencies
- 6. Simulation study

- STAR Meeting 8/29/07

## Run 4, AuAu 200 GeV ||<0.9, Zvertex, RF

- Run 4, AuAu 200 GeV ||<0.9, Zvertex, RF

- Zvertex, cm

## Run 4, AuAu 200 GeV ||<0.9, All EP, RF

- Run 4, AuAu 200 GeV ||<0.9, All EP, RF

## Run 4, AuAu 200 GeV ||<0.9, +/- EP, Vasily

- Run 4, AuAu 200 GeV ||<0.9, +/- EP, Vasily

## Run 4, AuAu 200 GeV ||<0.9, 

- Run 4, AuAu 200 GeV ||<0.9,

- 2500

## Run 4, AuAu 200 GeV ||<0.9, All EP, Zdc<2500

- Run 4, AuAu 200 GeV ||<0.9, All EP, Zdc<2500

## Run 4, AuAu 200 GeV ||<0.9, All EP, Zdc>2500

- Run 4, AuAu 200 GeV ||<0.9, All EP, Zdc>2500

## TPC Space Charge (In Run4 only simplified version of the Space Charge analysis is possible)
TPC Pad Efficiency 

- TPC Pad Efficiency

- TPC Study (not yet done)

***21***

## MC simulation : Hijing+Geant+Reconstruction

- MC Simulation

***21***

## MC simulation: Hijing 100K

- MC Simulation

***21***

## MC simulation : Hijing 100K

- MC Simulation

***21***

## 
Available MC events (39K) analysis shows a necessity of error reduction by factor  of ~10, which means simulation of ~1-5 M events for data sample  of AuAu 200 GeV. Other data also needs an independent simulation
Hijing simulation with and without flow is necessary to separate detector effects with the flow

- Available MC events (39K) analysis shows a necessity of error reduction by factor  of ~10, which means simulation of ~1-5 M events for data sample  of AuAu 200 GeV. Other data also needs an independent simulation
- Hijing simulation with and without flow is necessary to separate detector effects with the flow

- MC Simulation

## Exp AuAu 200 GeV - Run 4  23.4 M -> 12.0 M 
Exp AuAu   62 GeV  - Run4   13.7  M ->   8.3 M
Exp CuCu  200 GeV - Run5
Exp CuCu    62 GeV  - Run5
Exp AuAu  200 GeV – Run7

MC AuAu 200 GeV Run4  38.8K -> 21.2K
MC AuAu   62 GeV Run 4 100K
MC CuCu 200 GeV Run 5  54K 
MC CuCu   62  GeV Run 5  189K 
MC AuAu 200 GeV Run 7  100K

- Exp AuAu   62 GeV  - Run4   13.7  M ->   8.3 M
- Exp CuCu  200 GeV - Run5
- Exp CuCu    62 GeV  - Run5
- Exp AuAu  200 GeV – Run7
- MC AuAu 200 GeV Run4  38.8K -> 21.2K
- MC AuAu   62 GeV Run 4 100K
- MC CuCu 200 GeV Run 5  54K
- MC CuCu   62  GeV Run 5  189K
- MC AuAu 200 GeV Run 7  100K

- STAR Data & MC available

## CP Violating signals are seen in 3 data samples of  the Run 4: 62 GeV, 200 GeV (RF) and (FF)
Two independent analysis shows consistent results in the limits of statistical errors
In the limits of the stat. errors obtained results are in good agreement for high and low beam intensities
With same limits result doesn’t depend on a AuAu interaction vertex position
Analysis of Hijing simulated data was done; More simulated efforts are foreseen
Study of the TPC Space Charge and Pad efficiencies influence on the signals are planned  

- Two independent analysis shows consistent results in the limits of statistical errors
- In the limits of the stat. errors obtained results are in good agreement for high and low beam intensities
- With same limits result doesn’t depend on a AuAu interaction vertex position
- Analysis of Hijing simulated data was done; More simulated efforts are foreseen
- Study of the TPC Space Charge and Pad efficiencies influence on the signals are planned

- Summary

## Analysis of Run 5 (CuCu, 200 and 62 GeV) and Run 7 (AuAu 200 and 62 GeV) in planned. In this runs detailed study of the TPC space charge is possible 

- Summary (continued)