1 / 37

Tom Diehl July 8, 2002 Norman, Oklahoma

This report outlines the current status, accomplishments, challenges, and future goals of the Physics Groups focusing on B-Physics, Higgs, New Physics, QCD, Top, WZ, and common concerns. It covers datasets, results, worries, and plans discussed in a workshop in July 2002.

rachellc
Download Presentation

Tom Diehl July 8, 2002 Norman, Oklahoma

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  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

More Related