1. Jets and Met Group Many potential sources of new physics have final states consisting only of jets and MET. Jets + MET is a classic SUSY signature h,H,A ,  ’s decay hadronically In addition, final states containing soft leptons may not have acceptable trigger rates if we only use lepton-related trigger requirements h,H,A , one  decays leptonically the other hadronically bbH  bb  wino/zino  3l+MET sleptons  2l+MET

2. The Challenges Jets: lots of them around very slow turn-on curve  because the jet E T spectra is so steep, causes a very large number of jets that are below your offline thresholds to cause triggers The Jets ARE real. The whole trick here is sharpening the turn-on curve by making online as similar to offline, and the offline as similar to the parton-level as possible! MET: again, slow turn-on curve sensitive to tails of the multiple interaction distribution sensitive to any potential noise source (CDF’s texas towers, DØ’s Uranium noise) Optimization of MET resolution, to sharpen the turn-on curve and to prevent false MET in QCD events, especially in the presense of multiple interactions, is important. Elimination of noise sources is also important. A look at Level 1clearly shows the challenges...

3. The Challenges Sridhara Dasu If you set the single jet E T threshold to be 95% efficient for 205.5 GeV jets, you will trigger on jets with E T down to 100 GeV! Level 1: uses non-overlapping window algorithm (very non- offline)  for HLT, want algorithms, calibration as similar as possible to offline to avoid this affect!

4. The Challenges: MET experience from CDF/DØ tell us these turn on curves vary according to event topology, and are difficult to calculate or to estimate from data. need strategies for getting the efficiency for the combined L1/HLT turn-on. Level 1: Sridhara Dasu conversely, an 80 GeV MET threshold will only be 95% efficient for parton-level MET’s of 200 GeV. Not fully efficient for any kinematic region for squark and gluino’s. Dasu expects similar results for offline versus parton Met.

5. Plan 1) Understand how to achieve a factor 10 rejection over L1 using 25 % of the data. 2) while maintaining reasonable efficiency for difficult channels in the high luminosity physics menu SUSY jets+Met h,H,A ,  ’s decay hadronically h,H,A , one  decays leptonically the other hadronically

6. Basic Task List 1) Level 1 2) Monte Carlo Tuning 3) Monte Carlo Generation for Backgrounds 4) What Signals? 5)Design of Trigger Tables 6) Level 2.0 7) ORCA code for GHITS to DIGIS 8) ORCA code for jet clustering, corrections 9) ORCA code for MET 10) L2.x specific versions of the ORCA code 11) rejection, efficiency, data-size, rate calculations 12) methodology for determining efficiency Manpower situation more details on each topic In random order... It will be a long road… the current jets and MET effort is “embryonic”.

7. Man Power People on JPG Mailing List: (26, besides the “initiators”) Virgil Barnes, Serguei Bitoukov, Volker Drollinger, Alvise Favara, Vladimir Gavrilov, Dan Green, Nikolai Krasnikov, Alexandre Nikitenko, Hans Paar, David Stickland, Hans-Peter Wellisch, Sedat Ayan, John Hauptmann, Ed McCliment, Eugeny Doroshkevich, Vivan O’Dell, Shuichi Kunori, Nural Akchurin, John Womersley, Sridhara Dasu, Dmitri Litvintsev, Weimin Wu,Harvey Newman, Lawrence Sulak Minimum Requirements: 8 full-time people.

8. People Signed Up to Work 1) Level 1: Sridhara Dasu, Vivan O’Dell could use more in this essential area??? 2) Monte Carlo Tuning: Shuichi Kunori, Nural Akchurin, Dmitri Litvintsev manpower okay? 3) Monte Carlo Generation for Backgrounds Weimin Wu, Vivian O’Dell manpower okay? 4) What Signals? ??? 5)Design of Trigger Tables ??? 6) Level 2.0 ??? 7) ORCA code for GHITS to DIGIS Shuichi Kunori., Sarah Eno manpower okay? 8) ORCA code for jet clustering, corrections Hans-Peter Wellisch (Volker Drollinger, Sasha Nikitenko, Lars Sonnenschein, Evgeny Doroshkevich) DØ had about 9 people working in this area 9) ORCA code for MET John Hauptmann could use more in this essential area? 10) L2.x specific versions of the ORCA code ??? 11) rejection, efficiency, data-size, rate calculations ??? 9 people, all but 2 (?) part- time (some may be very part time!)

9. Backgrounds For the November milestone (factor 10 rejection) we are currently planning on using the brute-force approach of generating many background events. For the future, we may need to re-think this strategy, and develop parameterized methods, similar to those used in the past by E. Meschi for HLT electron rates. Vivian O’Dell and Weimin Wu of Fermilab are in charge of this project.

10. Monte Carlo Generation Fermilab has a 10 Sun farm, and is willing to do some large-scale Monte Carlo generation. CIT and Wisconson also have similar facilities, and are willing to help. Simulation can start once: 1) farm is commissioned (beginning May?) 2) We understand what HF simulation we will use We are currently planning on simulating 500,000 QCD events ( in same mixture as Dasu used for his Level 1 studies) and 50,000 Min Bias events. We expect to start in Mid-May, and to be finished by the end of June. Output will need 100 8mm tapes. We will keep 50,000 unbiased events, the min bias events, and all events that pass the L1 trigger (=1000) on disk at Fermilab (Dasu expects his L1 work to be done by mid-May.

11. Level 1 1) get current FORTRAN L1 into ORCA Sridhara Dasu (mid-April) 2) verify new code Vivan O’Dell (mid-May) 3) get HF into L1 simulation (important for MET) Sridhara Dasu (end-April) 4) check effect of real digitization simulation on rates ??? 5) verify that current L1 trigger table is adequate for all the physics we want to do ???

12. Trigger Tables: What Physics? One issue this group needs to address this at the same time as the HLT work: is this adequate for all the physics we need to do? What do we need at L2? Monitor triggers? L1 threshold rate Scalar ET 400 GeV 0.48 khz MET 80 GeV 1.29 khz 1jet 100 GeV 2.06 khz 2jets 60 GeV 2.17 khz 3jets 30 GeV 3.16 khz jet+e 50+12 GeV 1.35 khz (note, jets are 95% efficient at about 2xL1 thres met at 2.5xL1 thres) benchmarked against SUSY with M(LSP)=45 GeV, M(gluino)=300 GeV 83% efficient current high luminosity trigger table but, what about H ,  ’s decay hadronically??? offline: 2 jets >60 MET>40

13. Monte Carlo Tuning 1) Decide on HF simulation strategy for mid- May MC generation Shuichi Kunori, Nural Akchurin, Dmitri Litvintsev in time for mid-May MC generation investigating using latest version of HF shower library (April 1 version?) 2) re-tune HCAL simulation after summer test-beam Shuichi Kunori September MET rates may be sensitive to details of detector simulation, especially near cracks (though, Dasu’s studies indicate this is probably not true)

14. Level 2.0 at L2.0, we see what rejection we can get using the same data as was used in L1, but with more effective algorithms For jets, we can probably get our factor of 10 here in L2.0 just by using a real clustering algorithm, instead of the L1 fixed window algorithm. Have not yet thought about MET. pieces needed to do this have some manpower. need somebody to take responsibility for putting them together

15. ORCA GHITS to DIGIs Digitization and pileup effects could have a substantial effect on the turn-on curves. Need them to be simulated properly. Design and implementation of C++ Paganini Pascal and Romana Albert done by mid May? Customization for HCAL Shuichi Kunori and Sarah Eno done by end-of-May? manpower okay?

16. ORCA code for jet clustering, corrections Will want online code as similar as possible to offline code, to prevent smear-up effects. especially, want best possible jet energy calibration (taking into account eta dependency, etc) in HLT Library of different clustering algorithms: Hans-Peter Wellisch mid-May Tau-jet specific algorithms Sasha Nikitenko Using jet shape and multiplicity to reduce backgrounds Lars Sonnenschein Hcal calibration using single pions Evgeny Doroshkevich sharpening parton/offline turn-on, esp. for H  bb Volker Drollinger can use as many people as want to work

17. ORCA code for MET no thought has gone into this yet, though we do have 1 volunteer to do this (John Hauptmann)

18. Efficiencies, Rates, Rejections If we can get L1 into ORCA, HF into L1, digitization routines into ORCA, finish the Monte Carlo generation and at least 1 ORCA jet routine and 1 ORCA MET routine by the end of July, we can see in August if we can get the factor of 10 simply by using real clustering algorithms instead of the fixed window algorithms (probably true) and see that the efficiency for SUSY squarks/gluinos from the multi-jet trigger remains high. We will then be in a position to start to think about the more difficult Higgs to tau triggers in Sept/Oct. And, we’ll have built a team capable of dealing with this type of physics issue in the future. Will be challenging with current manpower, especially if they are distracted with other projects (as they are) manpower needed for this part of the project!

19. Summary 1) We have started to get a team together to work on this problem. However, more manpower is certainly needed. 2) We have started to identify strategies to get the required information in time for the November milestone. 3) It is possible to make the milestone, but only if we get more manpower, and if our current manpower is not too distracted by other tasks

21. Administrative Mailing List: cms-jetsmet@cms-lb.cern.ch Web Page: http://hepd01.physics.umd.edu/JPG/Default.htm First Meeting March 26: Introduction by me Overview of L1 jets and MET: Dasu Discussion of Task List: all video meetings of this type are painful. I would like to try to develop a “virtual” meeting where people post their talks on our web-page and the “audience” makes use of a netforum-like interface to place questions and receive answers. However, this will take time to develop. We would then have “real” meetings at CMS collaboration meetings. Second Meeting April 16. update on L1 : Dasu MC generation at Fermilab: Odell HCAL digitization: Kunori