Tom Diehl

July 8, 2002

Norman, Oklahoma

Report From the Physics Groups:

Status, Plans & Concerns

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?

Contents

Replies from the Physics Groups: B-Physics Higgs NewPhy QCD Top WZ

Common Elements in Plans & Concerns

Summary

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()<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.

B-Physics Accomplishments

Observed the J/Psi(), Ks(), p, and 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/ cross section

B-Physics Group J/ sample

~early June 2002

Very RecentlyB to J/ K

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?)

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.

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.

Higgs

Goal is to find the Higgs ~ 14 thesis students Data Samples are root-tuples on

Clued0 EM+jets, +jets, , 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).

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:

Higgs Accomplishments

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

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.

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.

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

New Phenomena

Susy, Non-SM ~ 25 thesis students Group Datasets? ICHEP results (5?)

– Search for 1st Gen. Leptoquarks

– Large Extra Dimensions

– Gauge Mediated SUSY (+MET)

+METevents

e+METevents

MET

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).

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.

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

Top

Interests: top production, decay properties, mass, non-sm top

~ 30 thesis students Data Sets

Root-tuples of EM+jets, +jets, , DIEM, EM 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)

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.

Top Accomplishments

Analysis concentrated on +jets, e+jets, & e

focusing on the W reconstruction. Non-W background estimates Techniques for isolating top

Showing @ ICHEP W(e) +jets, Z()+jets updates

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

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

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

Jet cross section when2 jets in trigger region

1 jet in trigger region

Region was0 < || < 0.8

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.

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.

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 , non-isolated , , EM+MET, EM+EM

See http://www-d0.fnal.gov/Run2Physics/wz/Public/database.html

Re-SAMED Pick_Events raw data.

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 ’, , Z Electron ID

– Non-linearity corrections

– Hadronic energy scale

– MET Tau ID

– Jet width (all jets skinny like’s) Luminosity

– The temporary loan of Marco V. becomes past due in just a couple days.

WZ Accomplishments

Lepton ID studies resulted in reduction in calorimeter zero suppression from 2.5to 1.5 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(e) & Z(ee) Cross sections and

Cross section ratio at sqrt(s)=1.96 TeV. EB Tuesday 09:30

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.

WZ Plans

We think it’s about time to rediscover the W().

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.

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.

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

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 +

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.

Common Elements in Concerns: Computing

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