t0 eventplane study

T0 EventPlane study

2013. 2. 5.Ko-ALICE MeetingMyunggeun Song

T0 config ( z= 373cm , -65 cm )

Multiplicity over All events from AMPT

True RP A-C side

• True RP : use all tracks in |eta| > 1 from AMTP

True RP Aside

True RP Cside

8Sector MethodMerge cells into colored 8 sectors.Evaluate EP with those 8 sectors.

Problem : Geometrical mean phi of sector is being used.( No consideration on Geometrical asymmetry and multiplicity in each cells )

Even weighted phi will not have geometrical symmetry.

8Sector method Aside

8Sector method Cside

True RP A – All sector A

• All Sector : – Use All cells to Evaluate Event plane– No correction

All Sector Aside

Modulation in Psi distribution.Be able to be expected analytically

However, Good resolution and no better idea yet

True RP C – All sector C

All Sector Cside

All Sector Cside

All sector A – All sector C

Resolution

• TrueRP A & TruRP C = 0.7523 ( 0.867 )• TrueRP A & AllSector A = 0.5437• TrueRP C & AllSector C = 0.7475• AllSector A & AllSector C = 0.3469 ( 0.589 )

Summary

• With AllSector method, resolution can be reached to 0.8(Cside) 0.6(Aside), 0.9(Full)– Not BAD!!

• Some other idea,– More Analytical development – Cut some cells which are at the outside of ideal

circle and phi equalize for the circle.

Further study

Further study