September 5, 2000D. Acosta -- USCMS Physics Meeting1 Muon PRS Group Darin Acosta (“Muon Guy”) University of Florida

September 5, 2000D. Acosta -- USCMS Physics Meeting2 Who’s Involved? l In Europe: è Ugo Gasparini et al. – Generator studies, L2 è Norbert Neumeister – DB prodn, L1, L2 è Anna Vitelli – DB prodn, barrel muon reconstruction è Several others with lesser involvement l In the U.S. (Endcap Muon group): è D. Acosta, S.M. Wang (UFlorida) – L1 è R. Breedon, T. Cox (UCD) – geometry, endcap recon. è B. Tannenbaum (UCLA) – L1 è R. Wilkinson (Caltech) – endcap recon., general guru

September 5, 2000D. Acosta -- USCMS Physics Meeting3 HLT Milestones l November 1999 è EMU missed completely. Insufficient time to develop code for geometry, digitization, persistence, and L1 from scratch in 6 months l July 2000 è EMU sort of met it. All pieces were in place, and preliminary results shown, but not enough time for tuning (P T assignment), debugging, and optimization (code was too slow for out-of-time pile-up). l September 2000 è Close to having all above issues resolved for dedicated L1 studies for the L1 TDR (due by Nov.) è But, goal line keeps moving: more demands on L1 trigger threshold definition (90% effic. vs. 50%)

September 5, 2000D. Acosta -- USCMS Physics Meeting4 U.S. Experience (1) l EMU group works well together è Lots of exchanges, video conferences, and meetings to keep everyone informed and on-track è A real user group where you can post a message (even dumb ones) and get help l EMU code development for ORCA is entirely a U.S. effort, with only minor consultation from Anna, Norbert, Vincenzo,… l We are heartened by Sarah’s comments: è “US muon has this [ORCA experience], which is one of the reasons I think they are so successful!” Because…

September 5, 2000D. Acosta -- USCMS Physics Meeting5 U.S. Experience (2) l This development has been painful: è Large C++/ORCA/SCRAM learning curve to climb (makes it hard for newcomers to contribute) è ORCA is a moving target: p Version doesn’t stay stable long enough to finish bug fixes, tuning, and collect results. p e.g. ORCA3  ORCA4 was a major switch after the November 1999 HLT meeting. It took many months before basic code was ready, which left little time for L1 developers to complete their work. We still had to rush for the July HLT meeting despite it being 8 months later! p ORCA 4.2  ORCA 4.3 has also been frustrating. Objectivity schema changed after July meeting, and it took a while before it was made backward compatible with previous DBs so that studies could continue to prepare for L1 TDR studies p Clearly development must occur, but it would help users if the underlying architecture would stay stable

September 5, 2000D. Acosta -- USCMS Physics Meeting6 U.S. Experience (3) l Some of this pain stems from none of the EMU developers being based at CERN è Attending the weekly RPROM meeting is not enough. Must have a door to knock on to get advice. l Long distance code development is slow, but most of us have no other choice. è Teaching duties, other active experiments, etc. l Thus, EMU is not 100% ready at time of milestones è Preliminary results shown by European colleagues (using our code) mislead CMS Collaboration p i.e. Poor L1 efficiency in DT/CSC overlap, poor L1 P T resolution – lots of bad PR that demoralizes group l Having a larger U.S. base of users and developers would improve efficiency of ORCA development

September 5, 2000D. Acosta -- USCMS Physics Meeting7 Recent Results Nevertheless, we have obtained some results on L1 performance: 95% Good efficiency in DT/CSC overlap region

September 5, 2000D. Acosta -- USCMS Physics Meeting8 More Work Needed L1 P T resolution shows difference between  + and  - ++ --

September 5, 2000D. Acosta -- USCMS Physics Meeting9 Near-Term L1 & HLT Goals l Must get Endcap Muon code perfected so that we can prepare efficiency and rate plots for the L1 TDR that are representative of the system performance è Last few bugs must be fixed l HLT Muon databases will be re-made with latest code è No new MC needs to be produced in U.S. right now p Caltech, UCD, UFlorida have contributed CMSIM samples in the past è Objectivity database formatting & Ntuple production done at CERN without U.S. EMU involvement p Norbert and Anna have done a lot of work on this, and have prepared the Ntuples used by the Muon groups. We should be doing more of this, particularly in preparing standard analysis jobs and Ntuples

September 5, 2000D. Acosta -- USCMS Physics Meeting10 Long-Term Plans l It would be nice to get the underlying EMU and L1 code finished so that we can move on to physics and HLT algorithms! è Hasn’t happened in parallel because the EMU users are also the developers l My personal selection of topics: è A fast L2 muon reconstruction package p Between that used by L1 and that used in offline analysis è A study of the reconstruction of muons in b-jets p Many important signals couple to b’s: Higgs, SUSY, … p Accompanying punch-through debris will deteriorate performance è Studies of your favorite physics topic that couples to muons: p Higgs: H  4l, H , WH  bb, ZH  bb p SUSY:  +  0  3l + MET

September 5, 2000D. Acosta -- USCMS Physics Meeting11 Summary l Clearly the Muon PRS group could use more involvement from people in the U.S. è Current members are over-stressed with demands è Many more things we could be doing but haven’t p L2 algorithms, physics studies, … è Might be a good training ground for new students before they commit to an analysis on CDF/D0 l But there is a significant learning curve to overcome to become effective è Requires a lot of time, a lot of patience l We’ve started a good collaboration in the U.S. è Future members shouldn’t have to suffer as much as we did!