current status of long-range correlation analysis in be+be at 150 gev/c evgeny andronov and andrey...

Current status of Long-Range correlation analysis in Be+Be at 150 GeV/c

Evgeny Andronov and Andrey [email protected]

Katowice29/01/2015

E.Andronov & A.Seryakov LUHEP SPbSU

St. Petersburg State UniversityLaboratory of Ultra-High Energy

Physics

mailto:[email protected]

2

Terminology

A.Capella et al., Phys.Rep. 236,225(1994)


3

Terminology

In the case of a linear correlation function slope parameter


4

Terminology

Possible types• - the correlation between charged particle multiplicities in backward (B) and

forward (F) rapidity windows

• - the correlation between the event mean transverse momentum in B and multiplicity in F

• -the correlation between the event mean transverse momenta in B and F

• - the correlation between the event net charges in B and F


5

Analysis technique: MC

DataEvent cuts: 1. T22. WFA 1.5 μs 3. ZCharge (by Emil) 4. BPD 5. Fitted Vertex 6. Fit Quality 7. Number of good vertex tracks >

2 8. Z coordinate +/- 5cm9. Centrality 0-20%

Track cuts: 1. Vertex track status and has

track2. Impact parameter X < 4cm Y <

2cm3. VTPC clusters > 14 or GapTPC >

44. All TPC clusters > 145. Pt < 1.5 GeV/c6. Acceptance map

MC Data (EPOS 1.99 by Emil)SimEvents

1. Centrality 0-20% 1. Pt < 1.5 GeV/c2. Acceptance map

RecEvents

1. Number of good vertex tracks > 2

2. Z coordinate +/- 5cm3. Centrality 0-20%

1. Vertex track status and has track

2. Impact parameter X < 4cm Y < 2cm

3. VTPC clusters > 14 or GapTPC > 4

4. All TPC clusters > 145. Pt < 1.5 GeV/c6. Acceptance map


6

Analysis technique: MC correction


10d THSparse: multiplicity Forward+ Forward- Backward+Backward- Pt Forward+ Forward- Backward+Backward-NetCharge Forward Backward

Bin_raw_corrected = Bin_raw*Bin_sim/Bin_rec

if Bin_sim or Bin_rec doesn’t exist

Bin_raw_corrected = Bin_raw

7

Analysis technique: MC correction


10d THSparse: multiplicity Forward+ Forward- Backward+Backward- Pt Forward+ Forward- Backward+Backward-NetCharge Forward Backward

Bin_raw_corrected = Bin_raw*Bin_sim/Bin_rec

if Bin_sim or Bin_rec doesn’t exist

Bin_raw_corrected = Bin_raw

𝑁𝑏𝑖𝑛𝑠𝑐𝑜𝑟𝑟𝑒𝑐𝑡𝑒𝑑𝑁𝑏𝑖𝑛𝑠

𝐹𝑜𝑟𝑤𝑎𝑟𝑑𝑤𝑖𝑛𝑑𝑜𝑤𝑐𝑒𝑛𝑡𝑒𝑟𝐵𝑎𝑐𝑘𝑤𝑎

𝑟𝑑𝑤𝑖𝑛𝑑

𝑜𝑤𝑐𝑒𝑛𝑡𝑒𝑟

short

range

long range

8

Short range correlation


9

Short range correlation: multiplicity


𝑏𝑐𝑜𝑟𝑟𝑟𝑒𝑙 =

⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

EPOS

Reconstructed data

Simulated data

Simulated without accept.

Real data

Raw data

Corrected data

10

Short range correlation: Pt-multiplicity



⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

EPOS

Reconstructed data

Simulated data


Real data

Raw data

Corrected data

11

Short range correlation: Pt



⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

EPOS

Reconstructed data

Simulated data


Real data

Raw data

Corrected data

12

Long range correlation


13

Long range correlation: multiplicity



⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

EPOS

Reconstructed data

Simulated data


Real data

Raw data

Corrected data

14

Long range correlation: Pt-multiplicity



⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

EPOS

Reconstructed data

Simulated data


Real data

Raw data

Corrected data

15

Long range correlation: Pt



⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

EPOS

Reconstructed data

Simulated data


Real data

Raw data

Corrected data

16




⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

EPOS

Reconstructed data

Simulated data


Real data

Raw data

Corrected data

Long range

17

Conclusions, results and plans …


• EPOS 1.99 doesn’t describe resonance decays in midrapidity

• Available statistic doesn’t allow to find string fusion (or another collective effects) in BeBe 150Gev/c. Probably they don’t exist here.

• The long-range pt-N behavior is an open question(Why is it below zero?)

Plans:• cut • modernization of the correction procedure• systematic errors

Pt-N

Real data

EPOS

Pt-Pt

Pt-N

18

Backup


19

Net charge correlation



⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

EPOS

Reconstructed data

Simulated data


Real data

Raw data

Corrected data

Long range

Short range

20




⟨𝐹 ⟩⟨𝐵 ⟩

⟨ 𝐵𝐹 ⟩− ⟨𝐵 ⟩ ⟨𝐹 ⟩⟨𝐹2 ⟩− ⟨ 𝐹 ⟩2

Centrality 0-20%

all charges

negative

positive

negative from forward |positive from backward

positive from forward |negative from backward

current status of long-range correlation analysis in be+be at 150 gev/c evgeny andronov and andrey...

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