Tom Diehl July 8, 2002 Norman, Oklahoma

1. Report From the Physics Groups: Status, Plans & Concerns Tom Diehl July 8, 2002 Norman, Oklahoma

2. Preparation for this talk • Workshop Goal: To form a plan so that we are capable of steady-state high-quality physics by the end of October shutdown. • Detector/Computing Systems • Trigger/Operations/Certifications • I asked the Physics Group Convenors (present & incoming) some questions • What datasets are you using? • What results and what have you learned about the process? • What concerns vis-à-vis the workshop goals? • What plans?

3. Contents • Replies from the Physics Groups: • B-Physics • Higgs • NewPhy • QCD • Top • WZ • Common Elements in Plans & Concerns • Summary

4. B-Physics • B-physics group is interested in b-quark production and decay, CKM-matrix, and CP-violation. • 17 Thesis Students Enlisted. • Group Datasets • A Muon+Jet certification sample of ~100,000 events in Runs 145089 to 149932. • ~100,000 Picked “medium” dimuons • 40,000 have M(mm)<10 GeV/c2. • 60,000 more have this cut removed. • All reprocessed with a special version of Reco p11 focusing on Tracking (HTF tracking is used). • ROOT-TUPLES are available on clue-d0.

5. B-Physics Accomplishments • Observed the J/Psi(mm), Ks(p+p-), L(pp-), and Y(mm) resonances. • Using the J/Psi sample, have measured the average B-quark lifetime. It’s consistent with PDG average. • Updated the MC generator from QQ to EvtGen which has better modeling of b-quark angular distributions. Also have an event-stripper which runs in the MC. • Analyses for ICHEP (3?) • Inclusive b cross section • J/y cross section

6. B-Physics Group J/y sample ~early June 2002 Very Recently B to J/Y(mm) K

7. B-Physics Worries • Tracking and Reconstruction • B-physics requires very high tracking efficiency for high- and low-pT tracks (in jets -htd). • Standard Reco pT track cutoff is 500 MeV • Sooo… they would like to tag selected events in Standard Reco for special processing or reprocessing (for scale, see their group data-samples -htd). • The optimal technical solution is to be determined. • SAM Stability (coupled to above?)

8. B-Physics Worries • Difficulty generating MC samples. Complaints about priority for his groups small jobs on the farms. • Physicist power dedicated to the software effort. • This will comes up again and again. I suspect you have already heard it today.

9. B-Physics Plans • Work on Mass-constrained kinematic fits to improve the proper time resolution. • The group is oriented towards muons and would like to get into B-tagging using electrons. • Interested in lowering the pT cut for leptons in the trigger to 1.5 GeV/c • Doing so will allow D0 somewhere between 10 and 25 TIMES more J/psi to dimuons and to be more than competitive with CDF. • Requires tracking in the trigger for unprescaled samples.

10. Higgs • Goal is to find the Higgs • ~ 14 thesis students • Data Samples are root-tuples on Clued0 • EM+jets, m+jets, mm, DIEM, multijet • Reco version p10.15.01 & p10.15.02 • Details available at http://www-d0.fnal.gov/~suyong/d0_private/Higgs_Streaming.html. • These are very well documented datasets (htd).

11. Higgs Accomplishments • Higgs Workshops • May 6th – 2 days evenly split between fundamentals, such as object ID and triggering, and physics talks. • June 28th – 1 day concentrated on analyses in progress. • Many Analyses in progress most advanced go to:

12. Higgs Accomplishments • ICHEP • bbbar+H to all b’s (DPF) • Fermiphobic Higgs to gg (DPF). • New: Higgs to WW to dileptons:

13. Higgs Wants/Worries • Monte Carlo • Ability for routine rereco on the farms (maybe OK now but a long time in coming). • Routine trigsim on the farms • Want all of the trigger objects available so they can study thresholds. • A large QCD sample for use with above. A detailed request will be forthcoming once trigsim is available on the farms.

14. Higgs Wants/Worries • Data Handling • How will the group deal with expected large data sample (B’s) that they will collect for signal, QCD background, B ID development. • They expect to make heavy use of pick-events to form their data samples. But Pick-events is a “bit of a kludge” (This comes up several times). • Many re-recos of medium-sized data samples. • B-ID critical for Higgs to bbbar • the group traded Meena to B ID.

15. Higgs Plans • Improve on Higgs workshop investigations using D0 Geant, trigger, & Reco • Inject reality into the MC • is it that the experts are busy and plan to return to this when we reach the nominal capability? -htd • Update the Higgs luminosity reach plot. • Concentrate on analyses that can be done in Run 2a with available tools. • Long Term • Prepare tools for the main SM channels WH, ZH -> leptons+bbbar

16. New Phenomena • Susy, Non-SM • ~ 25 thesis students • Group Datasets? • ICHEP results (5?) • Search for 1st Gen. Leptoquarks • Large Extra Dimensions • Gauge Mediated SUSY (gg+MET) M(mm) MET gg+MET events eg+MET events

17. New Phenomena Wants/Worries • Luminosity Database • They’d like it to be easier to use – run # and trigger should be enough (so naïve – htd). • Monte Carlo • Reco’d GEANT resolution doesn’t match real data. Retune OR produce the Run_II generalized analog of Run_I’s MU_SMEAR. OR … • Rely heavily on FMC. • Oddities in the Data • Need to be hunted down by end of October shutdown so that fixes can be implemented at the detector level (More on this later).

18. New Phenomena Wants/Worries • Better coordination of the software tools • Note that the probability of a Root macro working on a tuple different from that in which it was developed is smaller than desired.

19. New Phenomena Plans • Revisit the trigger list. • Changes in capability have outstripped the groups efforts at optimization (true for many groups). • Start to use thumbnails. • Organize better. • Large size compels them to form two subgroups in order to hear frequently about each analysis. • New subgroups are SUSY & Exotics

20. Top • Interests: top production, decay properties, mass, non-sm top • ~ 30 thesis students • Data Sets • Root-tuples of • EM+jets, m+jets, mm, DIEM, EMm • Reco version p10.15 • Luminosity tools are provided • Centralized Activities: • Top group Data samples • Data quality monitoring • Triggers for Top • Monte Carlo for Top • Analysis Tools (under way)

21. Top Accomplishments • Data Quality Monitoring • Produces “Good runs for Analysis” • Uses histos generated from roottuples • Provides feedback to detector/object ID/Farm groups – reco wrecked the muons recently and the top group discovered it. • Monte Carlo Samples Available • Trigger Studies • Large effort on Trigsim of data and M.C. • The WZ group has, on occasion, borrowed top group experts.

22. Top Accomplishments • Analysis • concentrated on m+jets, e+jets, & em focusing on the W reconstruction. • Non-W background estimates • Techniques for isolating top • Showing @ ICHEP • W(en) +jets, Z(mm)+jets updates

23. Top Wants/Worries • Monitoring • Would like more. • Would like Trigsim on the Farms as part of standard MC chain • Data Samples • Would like to remove obsolete/unusable (MC) samples in SAM • Need ability to quickly re-reco samples and without losing the luminosity information • Pick_events loses the luminosity information. Can this be changed? • B-tagging needs help • Trying for a bigger effort within their group

24. Top Plans • Continue to provide standard data samples for top (e.g. streamed root-tuples, thumbnails, + top_analyze package) • Trigger Studies • Widen scope by looking at more trigger and by using trigger info in the data • Catch up with the new trigger list • Monte Carlo • Study generators • Form subgroups soon in anticipation of stable physics running

25. QCD • Interests: Jets & Photons • 4 thesis students • Datasets: 6.3M jet events • Accomplishments • Tuple-stripping code • Contributions to Jet Energy Scale • Adapting to triggering without large tiles (so far) shows Region was 0 < |h| < 0.8 Jet cross section when2 jets in trigger region 1 jet in trigger region

26. QCD Accomplishments • New for ICHEP • Low Et Multijets (comparison to Pythia & Herwig) Run I • Diffractive W & Z Production • Run II Cross Sections in 5.8 pb-1 for 60 < ET(jet) <410 GeV and 150 < M(jj) < 750 GeV/c2.

27. QCD Plans & Concerns • Large Tiles – when? • Adopt to the new trigger capability and to the changes in the calor. including use of L2 and vertex in L3 jet algorithm. • A new version of jet algorithm: the “midpoint algorithm”. • Adopt to thumbnails will require • replacing the jet code that was constructed for root-tuples. • They support the idea that root-tuple = thumbnail.

28. WZ • Studies properties of the W and Z bosons, production and decay measurements, trilinear and quadrilinear couplings, some cross-over topics • ~ 6 thesis students • Datasets • Root-tuples produced from WZ Groups Reco-S stream containing sorted samples of Isolated m, non-isolated m, mm, EM+MET, EM+EM • See http://www-d0.fnal.gov/Run2Physics/wz/Public/database.html • Re-SAMED Pick_Events raw data.

29. WZ Accomplishments • Concentrating on contributing to object ID groups: • Muon ID • Scintillator timing cuts • Track-matching algorithm • Isolation studies ( p(fake) >Run I ). • Co-rediscovery of Y’, U, Z • Electron ID • Non-linearity corrections • Hadronic energy scale • MET • Tau ID • Jet width (all jets skinny like t’s) • Luminosity • The temporary loan of Marco V. becomes past due in just a couple days.

30. WZ Accomplishments • Lepton ID studies resulted in reduction in calorimeter zero suppression from 2.5s to 1.5s from pedestal starting with Run 158062. Silke & Nirmalya. • ICHEP • New W mass and W width results from Run I data. • Combined Run I results with CDF and the world • W(en) & Z(ee) Cross sections and Cross section ratio at sqrt(s)=1.96 TeV. EB Tuesday 09:30

31. WZ Wants/Worries • The WZ group’s ambitions (and potential) doesn’t match its size • Expect better documentation • of physics objects and physics procedures • Internal description of the data (which corrections & is it any good?) • Real Streaming is a • concern of everybody. • There’s a session on it here. • We don’t know if we will have the computer resources to carry out our plans for creating W and Z signal and background samples we need to do physics.

32. WZ Plans • We think it’s about time to rediscover the W(mn). • Replace some technical aspects of La Maccina so that SAM will do the bookkeeping • We are abandoning the reco-generated root-tuples in favor of Thumbnails for p11 • Need to develop the expertise • Need to ensure the Thumbnails contain all the chunks we require. • WZ group CVS C++ code • Algorithms perform analysis in D0framework on thumbnails • produces WZ_tuple • W & Z objects for monitoring.

33. Common Elements in Plans • Trigger • All groups sense they have fallen behind in understanding the triggers and making the most of the capability • Data Samples • Groups plan to migrate to thumbnails ASAP • Groups will continue to produce their own independent data samples • User-level analysis packages that are CVS released official things • Root-tuples have lead to inefficient progress in code development.

34. Common Elements in Concerns: Data • Data Integrity • Raw Data Quality • Implement the connection between Significant Event Server & Coor • Recorded Data Quality • Sometimes the readout screws up • One could imagine a chunk that could contain a summary of the summaries from all detectors which allows … • user to make a cut on “data-integrity” in thumbnail and root-tuples • Shpakov will make a proposal in the muon detector/algorithm meeting • Can Lum database info mark the events as they are processed in the Farm? • Good Runs Lists for ALL detectors from respective Object ID groups

35. Common Elements in Concerns: Computing • Concern about streaming, data-handling, & data-set construction • aggravated by poor communication between the physics groups and the computing experts (in CPB? Anal. Tools Gp?) • computing people don’t know what we want to do and we don’t know what is planned or possible • Not just in streaming and SAM, also in all aspects of the D0 analysis chain • Better Communication +

36. Common Elements in Concerns: Computing • A simulation of D0 computing would include models of • Central analysis systems, data handling & storage, CPU usage, network capability, etc … • Level of sophistication depends on the role of the system and its load • This would help physics groups • Decide how analyses would be structured and plan for time, manpower, and resources • This would help the computing experts • Determine where resources would be needed and how to adjust priorities for spending • Build a strong argument in case more resources are needed.

37. Summary • In light of the Workshop Goal • I reported the Physics Group Conveners (present & incoming) answers to • What datasets are you using? • What results and what have you learned? • What concerns vis-à-vis the workshop goals? • What plans? • I Highlighted some common plans and concerns (and some ideas) connected with doing analysis • Data quality, software effort, computing techniques and resources