IntroductionIntroduction

• Multi-jets final states are of major interest for the LC Physics

• EFlow : An essential test to design the foreseen detector

• Software (Algorithms) is as important as the hardware (detector) -> The two aspects are totally linked

Introduction P. Gay 2’

A study of an energy resolution of a digital calorimeter

A. Sokolov IHEP 20’

Simulation Studies for a digital Hadron Calorimeter

A. Maciel NIU 20’

Impact of the SET in photon measurement M. Berrgren

LPNHE 10’

Reconstruction Package for a LInear Collider J.C Brient LLR 10’

Comparisons of Fast Monte Carlo Energy flow Simulations

M. Ronan LBL 20’

BRAHMS reconstructionV. Morgunov Ties Benhke

DESY 20’

NLC Energy Flow studies N. Graf SLAC 20’

Analytic Energy flow P. Gay LPC 20’

Discussion about future plans All 20’

EFLOW session EFLOW session AGENDAAGENDA

8 talks for a 2:40 session with a significant contribution from US

Colleagues

Various topics covered : single particle reconstruction

Jets reconstruction Fast simulation

• EFlow : An essential test to design the performance of the detector

Then impact on Eflow of a new/alternative sub-detector has to be estimated

About the SET the question has been addressed in this way 20% of the photons in

processes HZ,WW, QQ have energy less than 5 GeV; if they convert SET improves their reconstruction Work is preliminary further work on Physics case with full simulation is expected

EFLOW procedureThe different approaches follow mainly similar scheme (JC Brient, N Graf, V Morgunov, PG)

Track cluster association following a tube/road in vicinity of the track extrapolation Remove in Calorimeters parts associated to charged clustersCharacterize remaining energy deposition (em and neutral hadron)

What do we need •Photon reconstruction and ID •neutral hadron and ID •test on full simulated Physics events

what do we have ?

Photon Many works have been developed with different approaches

•Classical clustering (JCBrient) •Stochastic approach/pattern recognition (PG)•Likelihood+covariance matrix (N Graf)

Studies performed w/ single particles but also in jet environment

Next Finalize when necessaryCompare the various options in term of performancePush on new preliminary ideas

Neutral hadron

Great importance and large impact

Neutral hadron reconstructed replaced by the Truth MC contribution

•Studies and comparisons between digital and analog hadron calorimeters (A. Maciel & A. Sokolov)

•At least similar results on resolution are obtained by both options •Improvements expected in both scheme, as an illustration, a NNet approach based on Hits multiplicities information (A. Sokolov) improves the resolution by a factor 1.4; further development foreseen

• Hits multiplicity and Em deposition in ECAL combined (PG)

Neutral hadron

Neutral hadron clustering (A. Maciel)•2D Layer/layer inspection and longitudinal stacking•Cell domain search in 3D (new idea)

Complete event environment and Eflow packages

Eflow packages appear with various levels of development

•MOKKA+REPLIC (JC Brient) already available on CALICE Coll. Web page•SNARK+BRAHMS (V. Morgunov) release very soon •Other stuffs foreseen for end of June (N. Graf & PG)

Sum of em energies Number of photon in an event

Test the Eflow performances

Two levels•1 Internally to the EFLOW group

We have to perform solid and conclusive comparisons between the different optionsunderstand what are the differences, the good/bad points, the discrepancies,

the bugs etc … Share the same events We will use benchmark processes : WW, ZZ, WWvv, ZZvv and tt @ 800 GeV The list is limited and this benchmark is an internal TOOL for Eflow

Share the same observables dijet energy resolution and dijet angle resolution

•Second level : input for Fast Simulation

outside Eflow group, People have to test the different Eflow options proposed in the context of Physics analyses

as an example Fast Simulation studies (M.

Ronan) Then Eflow group has to provide such an information

•Structure of input/output format has to be coordinated w/ Simulation group (of course)

•3rd Step Feedback from Physics analysis to EFLOW group in order to improve Eflow algorithm itself or sophistication of the provided output

Even if the man-power is presently small, many ideas are debated and developed

Newcomers are Welcome

NEXT Future

Provide results on Physics case (benchmarks) and perform the comparisons

Provide Eflow objects information to Fast Simulation

Reinforce connection with Tracker system people

Reinfornce Collab./synergy with US/ASIA colleagues