A. BHASIN ALICE offline Software Week 13th June 2002

Dimuon High Lelvel Trigger(DHLT)

Goals FM Algorithm Proposal for a new Algorithm

A. BHASIN ALICE offline Software Week 13th June 2002

DIMUON SPECTROMETER

A. BHASIN ALICE offline Software Week 13th June 2002

Goals

Demonstrate that algorithm can achieve 5-6 rate reduction using only small fraction of event data(from station 4 & 5).

Implement this algorithm in AliRoot framework(should be extractable for implementation on hardware)

Provision to include other tracking stations, trigger chamber, other detectors(ITS) and study the efficiency.

Need to validate the algorithms for Dimuon physics plan, taking into account all possible backgrounds.

A. BHASIN ALICE offline Software Week 13th June 2002

FM Algorithm

Muon Filter

Dipole

(xf,yf,zf)

Station 4Station 5

T1

YT2

(X,Y)T1

Rs

RPRO

T2

Franck Manso’s algorithm – Filtering and uses the hit information from stations 4 & 5 to improve the pT resolution and hence the pT cut – Helps in reducing the background .

A. BHASIN ALICE offline Software Week 13th June 2002

Proposed Algorithm

Hit finding in station 4 and 5 using the Raw Clusters (cog method). Make segments in each of these stations and calculate pT.

Validate the track in Station 3. Provision for including other Stations(1 &2),

Trigger chambers and other detectors for better track information.

A. BHASIN ALICE offline Software Week 13th June 2002

Implementation In AliRoot

galice.rootReadHits( )

RawClustersSt45( )FillEventHlt( )HltDecission( )

AliMUONHlt

Simple Clustering(C.O.G method)

only deconvulate clusters

AliMUON RawClusters

AliMUONEventReconstructor

SortHitsForRecInSt45( )MakeSegmentsPerStation( )

MakeSegments45( )MakeTracks( )

MaketrackCandidateswithTwosegments( )MakeTrackCandidatewithoneSegmentationandonepoint( )

MakeTrackCandidatesSt45( )RemoveDoubleTrack( )

FollowTracksinSt3usinghits( )FollowTracksinst1&2usingLUT( )

GetBendingMomentumFromImpactParameter( )

AliMUONHlt :: RawClustersSt45( )TreeR

AliMUONHlt::FillEventHlt( )

MUONHlt

TreeR