Progress on jet trigger response functions

FTK Physics Case Meeting

04/21/05

Erik Brubaker

University of Chicago

April 21, 2005 FTK Physics Case Meeting 2

Reminder: Purpose• Making the physics case for FTK means studying

signal and background trigger rates for several processes.

• ATLAS full simulation is very slow.

• Solution: use fully simulated events to parameterize the L1 jet trigger response vs ATLFAST jet pT. Then all the various processes for physics studies can be studied using ATLFAST.

April 21, 2005 FTK Physics Case Meeting 3

What I Done: Samples• No samples exist with the full L1 trigger simulation run

as part of the DC2/Rome production system—go back to Rome “simul” dijet samples: J1-J8.

• Three grids (LCG, NorduGrid, Grid3) used to simulate these samples—files scattered all over the world!

• Strategies to retrieve files (all require grid proxy):– RLS (Replica Locator Service?) + globus-url-copy.

– Don Quixote (with local modifications). Python wrapper for above + more.

– Find them sitting in dCache at BNL…

• I can share stupid-but-useful scripts and “expertise.”

April 21, 2005 FTK Physics Case Meeting 4

What I Done: jobOptions• Using 10.0.1, I didn’t need to change/recompile any

code, but coming up with the right jobOptions took a lot of work.

• Some default jobOptions had “bugs.”• A lot of trial & error to determine the right options to

run trigger simulation, digitization, and reconstruction (calorimeter/jet only).

• Was unable to find a way to generate AODs (Analysis Object Data?) with all the above requirements. Fell back to CBNT (Combined Ntuple).

April 21, 2005 FTK Physics Case Meeting 5

What I Done: Tier2 at UChicago• Last December, I learned how to run my

sim/reco jobs using the whole Grid3 framework.– Very useful for large-scale stuff.– At this stage, user jobs are a kludge. Takes a lot of

investment to learn what to do and stay on top of it.

• This time around, I found it easier and adequate to run jobs on a local condor queue at the UC tier2 facility.

• If you’re interested in either, ask me how to get started.

April 21, 2005 FTK Physics Case Meeting 6

Some definitions• Dijet samples:

– J1: 17 < pT < 35.

– J2: 35 < pT < 70.

– J3: 70 < pT < 140.

– J4: 140 < pT < 280.

– J5: 280 < pT < 560.

– J6: 560 < pT < 1120.

– J7: 1120 < pT < 2240.

– J8: 2240 < pT.

• Cone jets– R=0.7

– Seed > 2 GeV

• ATLFAST jets– Cone 0.4?

– Seed > 1.5 GeV?

• L1 jets– 4 x 4 trigger towers

• L1 taus– 1 x 2 trigger towers?

– Isolation?

April 21, 2005 FTK Physics Case Meeting 7

Simple distributions: ET J1-J4

April 21, 2005 FTK Physics Case Meeting 8

Simple distributions: ET J5-J8

April 21, 2005 FTK Physics Case Meeting 9

Simple distributions: J1-J4

April 21, 2005 FTK Physics Case Meeting 10

Simple distributions: J5-J8

April 21, 2005 FTK Physics Case Meeting 11

Matching study• Plot R between pairs of ATL+L1

jets.– Top: All such pairs in event.

– Bottom: R of the best such match (min R).

• Use R < 0.2 as a matching criterion for the rest of the studies.– Conservative cut.

– Strange feature at 0.16?

– Bump at 0.5 is FSR?

• What about unmatched jets?– Treat as matched to 0 GeV L1jet.

April 21, 2005 FTK Physics Case Meeting 12

The Money Plot• This 2d plot has all the information necessary to

provide the jet response functions needed.• Question is packaging: Histograms or function? Raw or

parameterized?

April 21, 2005 FTK Physics Case Meeting 13

Zoom out

Saturation in the triggerelectronics??

April 21, 2005 FTK Physics Case Meeting 14

Plans• Decide how to package the results—suggestions?

• Finish copying and running over all dijet files.

• Provide the answers for others to use in physics studies.

• Make similar functions for tau triggers.

• Investigate dependence on eta, jet flavor, etc.

• Get feedback from experts: does everything look reasonable?