HLab meetingStatus report

T.Gogami13/Sep/2011

12/Mar/2011 CNN News in D.C.

Contents

• CH2 & H2O Λ issue– ¼ σΛ(CH2) = σΛ(H2O)– Develop Tracking code

Experimental setup of JLab E05-115p(e,e’K+)Λ,(Σ0)

Experimental setup of JLab E05-115

Splitter Magnet

HKS

HES e’

K+

p(e,e’K+)Λ,(Σ0)

Analysis process

trackingx , x’ , y , y’ at Reference plane

x’ , y’ , pat Target

Missing Mass

trackingx , x’ , y , y’ at Reference plane

x’ , y’ , pat Target

p : Λ , Σ0 ,12ΛB

Angle : Sieve slit

F2T functionF2T function

particle ID(select K+)

HKSHES

tune tune

~40 hours(5 shifts)

JLab E05-115p(e,e’K+)Λ,Σ0

Very preliminary

Multiplicity of typical layer of chamberHES HKS

~1.13

~1.28

~2.24

~4.94

Multiplicity is high for HKS

Hit wires in KDC1

Overhead viewKDC1

Black : hit wires Blue : selected wiresRed : track

Black : hit wires Blue : selected wiresRed : track

CH2 52Cr

Misidentification chance in hit wires selection increase !

REAL DATA REAL DATA

low high low high

Overhead view

Basic tracking procedure

Good TDC

Pattern recognition

Track fit

Solve left right

Select good combination

Black : hit wires Blue : selected wiresRed : track

CH2 target

KDC1

52Cr target

Combination selection with TOF counters

Reduce hit wire combinations (h_tof_pre.f)

High multiplicity

Real data

New tracking scheme

Good TDC

Pattern recognition

Track fit

Solve left right

Select good combination

Combination selection with TOF counters

Reduce hit wire combinations (h_tof_pre.f)

High multiplicity

• Hit wire selection with TOF• 1X & 2X • Grouping

• Pre-PID• Cherenkov detectors

Reduce hit wires to analyze

みそ

DC hit info. selection with TOF (xx’)

Selective region Maximum gradient

Minimum gradient

Particle direction

Gravity

CUT~8%

~17%

Procedure in “h_dc_tofcut.f”1. Get KTOF1X & 2X hit counter information2. Make combination of 1X and 2X hit counter if those two are in

same group (grouping) 3. Determine cut conditions on KDC1 & KDC24. Select Hit wires in KDC and Reorder them

CUT

Just applied to xx’-layers for test

Check works of the code

• GREEN regionSelective region

• RED markersSelected hit wires

• BLACK markersRejected hit wires

Seems to work well

Particle direction

Gravity

Results of TOF cut with grouping

CH2 , 2.0 [μA] , 76315

Shift

Same

Residual

Multiplicity

CH2 , 2.0 [μA] , 76315

σ 150 [μm] σ 150 [μm]

~2.3

~1.2

before after

x x’ x x’

Apply to u,v-layer

Applied to uu’ and vv’ layers , too.

Selective region determined by 1X and 2X

Convert

v v’-layer

x x’-layer

Check works of the code

• GREEN region Selective region• RED markers & lines Selected hit wires• BLACK markers & lines Rejected hit wires

v v’ u u’

x x’

v v’ u u’

x x’

KDC1 KDC2particle particle

Results of TOF cut with grouping (all layers)

Residual

Multiplicity

CH2 , 2.0 [μA] , 76315

σ 150 [μm] σ 150 [μm]

Multiplicity of uu’vv’-layers• CH2

• ~20% reduction• 52Cr

• ~5-10% reduction

Same

before after

Results of TOF cut with grouping (all layers)

Faster !

Increase !TOF cut works well

52Cr

CH2

52CrFaster !

Increase !

Parameters ?

DC hit info. selection with TOF

Selective region Maximum gradient

Minimum gradient

Particle direction

Gravity

CUT~8%

~17%

CUT

Stricter TDC cut

Results of Introduction new code

Increased !

Increased !

CH2

52Cr

Summary

• CH2 & H2O Λ issue– Improvement of tracking code

• ¼ σ(CH2) = σ(H2O)==> ½ σ(CH2) = σ(H2O)

– Virtual photon flux calc.– efficiency

End

Multiplicity improvement history

Multiplicity went down !• Analysis time

– 20% reduction for 52Cr• Number of Kaon (RUN:77124, 52Cr)

– 56 70 90 130

Applied TDC cut

DC TOF cut Matrix DC TOF cut ‘ (TDC cut)

Result of TOF cut with groupingOriginal code

With “h_dc_tofcut.f”Pure Selective regionallowance

allowance

KDC

Too strict

select

Optimal allowance

Good tracks hid by background appear ! Number of K+ ~2[%] up

Experimental setup of JLab E05-115

Position, angle

Position, angle

e’

K+

Experimental setup of JLab E05-115

Position, angle

Position, angle

e’

K+

Momentum vector

Experimental setup of JLab E05-115

Momentum vector

Missing Mass~40 hours(5 shifts)

JLab E05-115p(e,e’K+)Λ,Σ0

Very preliminary

KTOF TDC

• Cut10000 – 50000 (Current)18000 – 20500 (New)

Run 76314 for CH2 targetRun 77124 for 52Cr target

Data Summary

JLab E05-115 (2009/June – 2009/Nov)