EMCAL HLT RoadmapEMCAL HLT RoadmapFederico RonchettiEMCAL/HLT CERN, May 18 2011

Status and OutlineStatus and OutlineHardware Installation• Full EMCAL configuration on the HLT side

Software Development: Triggers• EMCAL HLT trigger decisions:

cluster, jet, high pT electrons• L0/L1 Online Trigger Monitoring

People• Manpower

RCU Interface to HLT/DAQRCU Interface to HLT/DAQ

DAQLDC

HLTFEP

RCU

0RC

U 1

AB

BA

DDLOptical links

DDLSplitters

1 SM = 2 RCUs 10 SM = 20 DDL links 1 DDL link for the STU (HW jet trigger unit)

H-RORC (FPGA)

Connections LayoutConnections Layout

• 1 FEP node sees a sector in phi

• No changes in the online chain setup…

FEPEMCAL0

A-side

C-side

HLT TriggersHLT Triggers

• Cluster trigger• Jet trigger• High pT electron trigger

-g p0 discrimination: three possible cases:

well separated clusters

opening angle << cell dimension

all 0’s at this energy are in jets

isolation cut

pT <10 GeV/c

ClusteringClustering

merged clusters

shower shape analysis

R

EMCal

TPC

candidate

IP

Isolated if:• no particle in

cone with pT

> pT thres

OR• pT sum in

cone, SpT < SpT

thres

10< pT< 40 GeV/c pT >40 GeV/c

invariant mass

analysis

ClusteringClustering

• V1 clusterizer in place in HLT/CALO (common code for EMCAL and PHOS)

• TODO: Introduce shower shape into the V1 clusterizer • Alternative: finalize the implementation of the NxN CALO

clusterizer (EMCAL N=3, PHOS N=5)• TODO: debug and test the NxN clusterizer• TODO: check geometry definitions for modifications

after the upgrade to 10 SM• Cluster trigger component in place (simple threshold)

need review.

High pT Electron TriggerHigh pT Electron Trigger• At ET>>mq heavy quark jet production probe the color

charge dependence of energy loss.• C hadrons reconstruction

goes with TPC+ITS+TRD• B hadrons need fast e-

trigger for pT>10 GeV/c (where no TRD)

• Identification via E/pin EMCal

• TPC tracks are extrapolated and matched to EMCal clusters

Main background sources: 1. Dalitz decay of neutral

mesons2. photon conversions

in ITS and beam pipe

High pT Electron TriggerHigh pT Electron Trigger

TODO: Provide HLT decisions for high pT electrons• Implement the track-cluster matching on HLT

side• Need extrapolation method for HLT tracks (ESD) -

helix propagation to XYZ point (Sergey from TPC can help)

• cut on E/P (~1) for electron candidate tracks • candidates pre-selected with requirement of• pointing to the interaction vertex • Electron dE/dx from TPC – not available right

now, may not be needed.

JetsJets

TODO: Provide HLT decisions for jets:• Implement a jet finder component running the

anti-kT recombination algorithm; • Inputs: central barrel track (considering pT cuts)

and EMCal cells (3-vectors Ex,Ey,Ez); • algorithm removes the cells matching to the tracks

before next pass• extrapolation method for HLT tracks (ESD) - helix

propagation to impact point on EMCal ( Sergey)• Correlation with centrality information

(V0 component in place)

Calibration and MonitoringCalibration and Monitoring

TODO:• Cell energy spectra per Super Module; • Display the L0 and L1 trigger primitives • Cluster spectra with L0 trigger bit set vs

overall cluster distribution;

Key point: Need to associate the cluster (reconstructed data) with the trigger bit (raw data)

Software DevelopmentSoftware DevelopmentOpen Issues:Need testing HLT “offline” with its AliRoot/HLT subsystem:• We can run HLT in AliRoot with simulated data • Problem with HLT in AliRoot with real data

(needed to develop online calibration and monitoring tasks)

last update: end of march 2011Need to follow this up once back at CERN

EMCAL/HLT PeopleEMCAL/HLT PeoplePeople interested in EMCal HLTAUSTIN:• Leonidas Xaplanteris at CERN (F. Ronchetti)• Summer student at LNF (P. Gianotti)

CERN:• Francesco Blanco (Huston) is considering to join• Jiri Kral (Jyväskylä) may join after his assignment

to L0 is over (not easy to replace him).• PhD student from S. Paolo U. at CERN on may-

june could contribute on the hi-pT electron trigger.

LNF:• Post Doc person? (need to define support)