status report on ifr physics issues

Status Report on IFR Physics IssuesStatus Report on IFR Physics Issues

IFR Barrel Replacement Workshop, November 15, 2002IFR Barrel Replacement Workshop, November 15, 2002

Jeff RichmanJeff RichmanUC Santa BarbaraUC Santa Barbara

Physics Session AgendaPhysics Session Agenda

SpeakerSpeaker SubjectSubject Start TimeStart Time Talk+Discussion Talk+Discussion TimeTime

Jeff RichmanJeff Richman Physics of the IFR: Physics of the IFR: OverviewOverview

10:0010:00 15’+5’15’+5’

David LangeDavid Lange Monte Carlo studies with Monte Carlo studies with the IFRthe IFR

10:2010:20 20’+10’20’+10’

Gianluca CavotoGianluca Cavoto Monte Carlo studies with Monte Carlo studies with the IFRthe IFR

10:5010:50 15’+10’15’+10’

Oliver BuchmuellerOliver Buchmueller Muon studies: data vs. Muon studies: data vs. MCMC

11:1511:15 10’+5’10’+5’

Jeff BerryhillJeff Berryhill Muons in BMuons in BKllKll 11:3011:30 10’+5’10’+5’

Bryan DahmesBryan Dahmes KKLL studies in B studies in BJ/J/KKLL 11:4511:45 10’+5’10’+5’

Urs LangeneggerUrs Langenegger KKLL veto in B veto in BXXuu l l 12:0012:00 5’+5’5’+5’

OutlineOutline

Charge, people, organizationCharge, people, organization

Questions to addressQuestions to address

Physics program for the IFRPhysics program for the IFR

Benchmark detector/absorber layoutsBenchmark detector/absorber layouts

Most relevant part of the charge to IFR Most relevant part of the charge to IFR Replacement Review Committee for physics Replacement Review Committee for physics

studiesstudies The committee should advise on improvements that

can be made to the muon identification in the barrel IFR based on the foreseeable physics goals of the experiment.

In particular, this includes improvements in pion rejection due to increased material inserted in the barrel gaps in place of sensing layers.

The committee should revisit the issue of muon identification/pion rejection efficiency versus KKLL identification/veto efficiency and provide a clear statement of priorities for the IFR.

People involvedPeople involved David Lange (LLNL) [consultant to the committee]David Lange (LLNL) [consultant to the committee]

Gianluca Cavoto (Rome/Princeton): MC studiesGianluca Cavoto (Rome/Princeton): MC studies

Ajit Mohapatra (U. Wisconsin): MC studiesAjit Mohapatra (U. Wisconsin): MC studies

J.D.R.J.D.R.

People working on specific studiesPeople working on specific studies

Joerg Stelzer (SLAC), Danning Dong (SLAC): Ds Oliver Buchmueller (SLAC): data vs. MC comparisons

Bryan Dahmes (UCSB): KL information

Jeff Berryhill (UCSB):BK(*)l+l-

Gabriella Sciolla (MIT): tagging in BJ/ K

Tina Cartaro (Naples): IFR endcap studies

Urs Langenegger (SLAC): KL veto in BXu l

Web page for collecting information Web page for collecting information on physics studies for IFRon physics studies for IFR

http://www.slac.stanford.edu/BFROOT/www/Detector/IFR/lange/IfrBarrelUpgrade/

We already have a full page of links to new plots, as We already have a full page of links to new plots, as well as previous studies. well as previous studies.

There are lots of basic plots related to muon ID.There are lots of basic plots related to muon ID.

Much of the hard work is being done by Much of the hard work is being done by David Lange,David Lange, Ajit Mohapatra, and Gianluca Cavoto.Ajit Mohapatra, and Gianluca Cavoto.

We have been meeting Monday mornings at 8:30. See We have been meeting Monday mornings at 8:30. See IFR Improvement Hypernews.IFR Improvement Hypernews.

Absorber Absorber in in frontfront of the of the

IFRIFR

Basic features Basic features of the IFR: of the IFR: absorber absorber traversed to live traversed to live chamber in fullchamber in fullsimulationsimulation

Current barrelCurrent barrel

Old endcapOld endcap

MC study; MC study; chamber chamber inefficiencies inefficiencies includedincluded

Basic features of the IFR: acceptance vs. Basic features of the IFR: acceptance vs.

folded distributionfolded distribution

What questions should we ask? What questions should we ask?

1.1. What are the physics measurements that motivate and What are the physics measurements that motivate and justify the IFR Barrel replacement?justify the IFR Barrel replacement?

2.2. For important processes with muons, how much For important processes with muons, how much absorber would make a absorber would make a significant differencesignificant difference in in improving the quality of the measurement?improving the quality of the measurement?

3.3. What are the minimal requirements for What are the minimal requirements for KKL L ID? Can a ID? Can a KKLL veto be effective? veto be effective?

4.4. What are the requirements on detector efficiency, What are the requirements on detector efficiency, resolution, and granularity?resolution, and granularity?

…….and get the answers by Dec 8.and get the answers by Dec 8

ProcessProcess Physics Physics KKLL CommentsCommentsBR, BR, VVub ub , , dN/dqdN/dq22 ****** *(?)*(?) stat, high pstat, high p

BR, BR, VVub ub , , dN/dqdN/dq22 ****** *(?)*(?) stat, high pstat, high p

BR, BR, VVubub ****** *(?)*(?) stat, high pstat, high p

BR, BR, VVubub **** *(?)*(?) high phigh p

BR, BR, VVcb cb , , dN/dqdN/dq22 **** stat: high stat: high qq22

BR, BR, VVcb cb , , dN/dqdN/dq22 **** stat: high stat: high qq22

BRBR **** statstat

BR, BR, VVcb cb **** sys (no brem)sys (no brem)

BR, BR, VVcb cb **** sys (no brem)sys (no brem)

BRBR **** *(?)*(?) statstat

BR, Loops/N.P.BR, Loops/N.P. ******** statstat



BR, Loops/N.P.BR, Loops/N.P. -- **(?)**(?) statstat

BR, Loops/N.P.BR, Loops/N.P. ****** stat, high pstat, high p

BR, Loops/N.P.BR, Loops/N.P. ****** statstat

BR, N.P.BR, N.P. ****** **(?)**(?) statstat

B , B

reco ( )uB X B

B D *B D

* (*)1 2, , B D D D

(inclusive)cB X

(*)B D B K

*B K sB X

B KB B

, B

(incl. endpoint)uB X

(incl.; tag)cB X

ProcessProcess Physics Physics KKLL CommentsCommentsCP: sin(2CP: sin(2)) ****

CP: sin(2CP: sin(2)) **** ********

CP: sin(2CP: sin(2)) ****

mmdd ****

******** high phigh p

********

ISR processesISR processes ****

0/ SB J K0/ LB J K*/B J K

sD

0 0 mixing ( / )B B

What about tagging for CP measurements?What about tagging for CP measurements?

Now have study by Gabriella Sciolla (http://babar-Now have study by Gabriella Sciolla (http://babar-hn.slac.stanford.edu:5090/HyperNews/get/sin2beta/488/1.html)hn.slac.stanford.edu:5090/HyperNews/get/sin2beta/488/1.html)

set the muon ID efficiency to zero

retrain the tagger and then test on an independent sample

Go from total Q=30.3% to Q=29.1%

Get partial recovery into other tagging categories

ApproachesApproaches

1.1. Study some specific processes of interest. Study some specific processes of interest. Understand the role of muon ID and fake-Understand the role of muon ID and fake-muon backgrounds.muon backgrounds.

2.2. Generic approach: estimate Generic approach: estimate efficiencies efficiencies and and fake probabilities vs. momentum fake probabilities vs. momentum and cos(and cos(). ).

3.3. Compare different ``benchmark’’ detector Compare different ``benchmark’’ detector layouts. layouts.

Issues for new detector/absorber layoutsIssues for new detector/absorber layouts

The difficulty in replacing the detectors in Layer 19 presents a The difficulty in replacing the detectors in Layer 19 presents a very serious problem, since we effectively lose 10 cm (0.6 very serious problem, since we effectively lose 10 cm (0.6 intint) ) of absorber before we even start with our design.of absorber before we even start with our design.

Replacing one detector layer with 2.2 cm brass restores only Replacing one detector layer with 2.2 cm brass restores only 0.15 0.15 intint need to replace 4 layers just to break even! need to replace 4 layers just to break even!

Note: CLEO has 3 detector triplets following Note: CLEO has 3 detector triplets following intint=3, 5, 7.=3, 5, 7.

In spite of this, I think that the most important physics issue is In spite of this, I think that the most important physics issue is high high detection efficiency. detection efficiency.

Presumably, we should retain detectors in layer 1 for track Presumably, we should retain detectors in layer 1 for track linking with the DCH. However, all BaBar muon selectors linking with the DCH. However, all BaBar muon selectors currently require at least 2currently require at least 2so so detection before this detection before this amount of material is not very important.amount of material is not very important.

Currently, Currently, KKLL ID requires hits in two successive layers. ID requires hits in two successive layers.

Benchmark DesignsBenchmark Designs D. Lange, L. Cavoto, T. Cartaro, and J.D.R. have decided on D. Lange, L. Cavoto, T. Cartaro, and J.D.R. have decided on

6 benchmark designs to answer some basic questions. 6 benchmark designs to answer some basic questions.

Absorbers added to Absorbers added to layerslayers

Detector efficiencyDetector efficiency

=0.85 =0.85

Detector efficiencyDetector efficiency

=0.95=0.95

8, 10, 12, 14, 168, 10, 12, 14, 16

=5.1=5.1

BD1aBD1a BD1bBD1b

5, 7, 9, 11, 13, 155, 7, 9, 11, 13, 15

=5.3=5.3

BD2aBD2a BD2bBD2b

2, 3, 4, 5, 7, 9, 11, 13, 152, 3, 4, 5, 7, 9, 11, 13, 15

=5.7 (still not a lot!!!)=5.7 (still not a lot!!!)

BD3aBD3a BD3bBD3b

Can more material be added? Earthquake issues…Can more material be added? Earthquake issues…

Benchmark Design #1 (add 5 absorber layers)Benchmark Design #1 (add 5 absorber layers)Layer X=Thickness (cm) LamInt=NucIntLen (cm)X/LamInt=Thick/N.I.L. Cum X/LamInt Delta CumX/LamInt

0.5 18.50 16.80 1.101 1.10 Absorber before IFR; just a guess1.0 0.00 1000.00 0.000 1.10 1.10 Detector1.5 2.00 16.80 0.119 1.22 Permanent absorber layer2.0 0.00 1000.00 0.000 1.22 0.12 Detector2.5 2.00 16.80 0.119 1.34 Permanent absorber layer3.0 0.00 1000.00 0.000 1.34 0.12 Detector3.5 2.00 16.80 0.119 1.46 Permanent absorber layer4.0 0.00 1000.00 0.000 1.46 0.12 Detector4.5 2.00 16.80 0.119 1.58 Permanent absorber layer5.0 0.00 1000.00 0.000 1.58 0.12 Detector5.5 2.00 16.80 0.119 1.70 Permanent absorber layer6.0 0.00 1000.00 0.000 1.70 0.12 Detector6.5 2.00 16.80 0.119 1.82 Permanent absorber layer7.0 0.00 1000.00 0.000 1.82 0.12 Detector7.5 2.00 16.80 0.119 1.93 Permanent absorber layer8.0 2.20 15.00 0.147 2.08 Fill gap with absorber8.5 2.00 16.80 0.119 2.20 Permanent absorber layer9.0 0.00 1000.00 0.000 2.20 0.38 Detector9.5 2.00 16.80 0.119 2.32 Permanent absorber layer

10.0 2.20 15.00 0.147 2.47 Fill gap with absorber10.5 3.00 16.80 0.179 2.64 Permanent absorber layer11.0 0.00 1000.00 0.000 2.64 0.44 Detector11.5 3.00 16.80 0.179 2.82 Permanent absorber layer12.0 2.20 15.00 0.147 2.97 Fill gap with absorber12.5 3.00 16.80 0.179 3.15 Permanent absorber layer13.0 0.00 1000.00 0.000 3.15 0.50 Detector13.5 3.00 16.80 0.179 3.33 Permanent absorber layer14.0 2.20 15.00 0.147 3.47 Fill gap with absorber14.5 5.00 16.80 0.298 3.77 Permanent absorber layer15.0 0.00 1000.00 0.000 3.77 0.62 Detector15.5 5.00 16.80 0.298 4.07 Permanent absorber layer16.0 2.20 15.00 0.147 4.22 Fill gap with absorber16.5 5.00 16.80 0.298 4.51 Permanent absorber layer17.0 0.00 1000.00 0.000 4.51 0.74 Detector17.5 10.00 16.80 0.595 5.11 Permanent absorber layer18.0 0.00 1000.00 0.000 5.11 0.60 Detector


0.5 18.50 16.80 1.101 1.10 Absorber before IFR; just a guess1.0 0.00 1000.00 0.000 1.10 1.10 Detector1.5 2.00 16.80 0.119 1.22 Permanent absorber layer2.0 0.00 1000.00 0.000 1.22 0.12 Detector2.5 2.00 16.80 0.119 1.34 Permanent absorber layer3.0 0.00 1000.00 0.000 1.34 0.12 Detector3.5 2.00 16.80 0.119 1.46 Permanent absorber layer4.0 0.00 1000.00 0.000 1.46 0.12 Detector4.5 2.00 16.80 0.119 1.58 Permanent absorber layer5.0 2.20 15.00 0.147 1.72 Fill gap with absorber5.5 2.00 16.80 0.119 1.84 Permanent absorber layer6.0 0.00 1000.00 0.000 1.84 0.38 Detector6.5 2.00 16.80 0.119 1.96 Permanent absorber layer7.0 2.20 15.00 0.147 2.11 Fill gap with absorber7.5 2.00 16.80 0.119 2.23 Permanent absorber layer8.0 0.00 1000.00 0.000 2.23 0.38 Detector8.5 2.00 16.80 0.119 2.35 Permanent absorber layer9.0 2.20 15.00 0.147 2.49 Fill gap with absorber9.5 2.00 16.80 0.119 2.61 Permanent absorber layer

10.0 0.00 1000.00 0.000 2.61 0.38 Detector10.5 3.00 16.80 0.179 2.79 Permanent absorber layer11.0 2.20 15.00 0.147 2.94 Fill gap with absorber11.5 3.00 16.80 0.179 3.12 Permanent absorber layer12.0 0.00 1000.00 0.000 3.12 0.50 Detector12.5 3.00 16.80 0.179 3.30 Permanent absorber layer13.0 2.20 15.00 0.147 3.44 Fill gap with absorber13.5 3.00 16.80 0.179 3.62 Permanent absorber layer14.0 0.00 1000.00 0.000 3.62 0.50 Detector14.5 5.00 16.80 0.298 3.92 Permanent absorber layer15.0 2.20 15.00 0.147 4.06 Fill gap with absorber15.5 5.00 16.80 0.298 4.36 Permanent absorber layer16.0 0.00 1000.00 0.000 4.36 0.30 Detector16.5 5.00 16.80 0.298 4.66 Permanent absorber layer17.0 0.00 1000.00 0.000 4.66 0.30 Detector17.5 10.00 16.80 0.595 5.26 Permanent absorber layer18.0 0.00 1000.00 0.000 5.26 0.60 Detector


0.5 18.50 16.80 1.101 1.10 Absorber before IFR; just a guess1.0 0.00 1000.00 0.000 1.10 1.10 Detector1.5 2.00 16.80 0.119 1.22 Permanent absorber layer2.0 2.20 15.00 0.147 1.37 Fill gap with absorber2.5 2.00 16.80 0.119 1.49 Permanent absorber layer3.0 2.20 15.00 0.147 1.63 Fill gap with absorber3.5 2.00 16.80 0.119 1.75 Permanent absorber layer4.0 2.20 15.00 0.147 1.90 Fill gap with absorber4.5 2.00 16.80 0.119 2.02 Permanent absorber layer5.0 2.20 15.00 0.147 2.16 Fill gap with absorber5.5 2.00 16.80 0.119 2.28 Permanent absorber layer6.0 0.00 1000.00 0.000 2.28 1.18 Detector6.5 2.00 16.80 0.119 2.40 Permanent absorber layer7.0 2.20 15.00 0.147 2.55 Fill gap with absorber7.5 2.00 16.80 0.119 2.67 Permanent absorber layer8.0 0.00 1000.00 0.000 2.67 0.38 Detector8.5 2.00 16.80 0.119 2.79 Permanent absorber layer9.0 2.20 15.00 0.147 2.93 Fill gap with absorber9.5 2.00 16.80 0.119 3.05 Permanent absorber layer

10.0 0.00 1000.00 0.000 3.05 0.38 Detector10.5 3.00 16.80 0.179 3.23 Permanent absorber layer11.0 2.20 15.00 0.147 3.38 Fill gap with absorber11.5 3.00 16.80 0.179 3.56 Permanent absorber layer12.0 0.00 1000.00 0.000 3.56 0.50 Detector12.5 3.00 16.80 0.179 3.74 Permanent absorber layer13.0 2.20 15.00 0.147 3.88 Fill gap with absorber13.5 3.00 16.80 0.179 4.06 Permanent absorber layer14.0 0.00 1000.00 0.000 4.06 0.50 Detector14.5 5.00 16.80 0.298 4.36 Permanent absorber layer15.0 2.20 15.00 0.147 4.50 Fill gap with absorber15.5 5.00 16.80 0.298 4.80 Permanent absorber layer16.0 0.00 1000.00 0.000 4.80 0.74 Detector16.5 5.00 16.80 0.298 5.10 Permanent absorber layer17.0 0.00 1000.00 0.000 5.10 0.30 Detector17.5 10.00 16.80 0.595 5.70 Permanent absorber layer18.0 0.00 1000.00 0.000 5.70 0.60 Detector

Studies Planned for Benchmark DesignsStudies Planned for Benchmark Designs

1.1. Make material maps of each design: Make material maps of each design: vs. vs. cos(cos().).

2.2. Make detailed performance plots for two Make detailed performance plots for two separate regions in cos (separate regions in cos (). ).

Barrel/Fwd endcap overlap region: 0.7< Barrel/Fwd endcap overlap region: 0.7< radianradian

Barrel region: 1< Barrel region: 1< radiansradians

ConclusionsConclusions

1.1. We have a lot to do in a very short time, but We have a lot to do in a very short time, but results will start appearing rapidly.results will start appearing rapidly.

2.2. We need to get your input We need to get your input nownow..

3.3. Thanks to all who are helping out!Thanks to all who are helping out!

Backup SlidesBackup Slides

Performance PlotsPerformance Plots1.1. Muon efficiency vs. pMuon efficiency vs. p

2.2. Prob(Prob() vs. p ) vs. p

3.3. Prob(Prob() vs. muon efficiency in slices of momentum:) vs. muon efficiency in slices of momentum:

0.5<p<1.0 GeV/c; 1.0<p<1.5 GeV/c; 1.5<p<2.5 GeV/c; p>2.5

4.4. distributions: distributions: and and as separate curves on one plot. Make as separate curves on one plot. Make plots in same momentum slices as given above.plots in same momentum slices as given above.

5.5. KKLL efficiency vs. p efficiency vs. p

6.6. Scatterplots of Scatterplots of vs. cos( vs. cos() for ) for and and samples. Use same samples. Use same momentum slices as given above.momentum slices as given above.

7.7. If possible: If possible: fake-rate decomposition vs. pfake-rate decomposition vs. p

decays before and within the IFR

punchthroughs or sailthroughs (no decay)

Other IssuesOther Issues

1.1. We hope to perform some data vs. MC comparisons We hope to perform some data vs. MC comparisons (( KKLL efficiencies, efficiencies, fake probs) using data fake probs) using data samples from early 2000, when the RPC efficiencies samples from early 2000, when the RPC efficiencies were reasonably high. were reasonably high.

2.2. A question I would like to answer:A question I would like to answer:

How much absorber would we need to add to the IFR before the fake prob from non-decaying pions is reduced to one-half the fake prob from decaying pions?

Basic features of Basic features of the IFR:the IFR:absorber absorber traversed to live traversed to live chamber with chamber with perfect chamber perfect chamber efficiencies efficiencies

Current barrelCurrent barrel


MC studyMC study

Basic features of Basic features of the IFR: absorber the IFR: absorber traversed to live traversed to live

chamber w/o L19chamber w/o L19

Current Current barrelbarrel


Layer 19 Layer 19 removedremoved

Perfect Perfect efficiency efficiency for other for other chamberschambers

Benchmark physics processes: muonsBenchmark physics processes: muons There are many processes with muons that will important to There are many processes with muons that will important to

the the BBAABBARAR physics program for many years. physics program for many years.

B D* l : largest branching fraction of any B decay, |Vcb |, intermediate momentum spectrum; int =5 prob. sufficient.

B l (hard lepton spectrum), B l , | Vub | int >5 ?

BK(*)l+l- (efficiency is very important); BXs l+l-

BXu l inclusive, | Vub | (high-p muons, contin. bkgnd.)

e+e- Ds*Ds ; Ds (fakes int >5 ?), fDs

B J/KS J/l+l- (muon ID barely needed)

We are making the momentum and range spectra (number We are making the momentum and range spectra (number interaction lengths) for these processes as a function of cos(interaction lengths) for these processes as a function of cos().).

Muon momentum spectra for key modesMuon momentum spectra for key modes

B l (see web page for many more)(see web page for many more)

sD

Muon momentum spectra for key modes:Muon momentum spectra for key modes:cos(cos() vs. p) vs. plablab

B l *B D l

Muon penetration in iron vs. momentumMuon penetration in iron vs. momentum(Geant Toy MC)(Geant Toy MC)

=5=5

=10=10

Probability for a muon to penetrate Probability for a muon to penetrate LL interaction interaction lengths vs. momentumlengths vs. momentum

3344 7755 66LL=2=2 88

90%90%

Benchmark physics processes: Benchmark physics processes: KKLL

Currently, the role of Currently, the role of KKL L identification in the BaBar physics program is identification in the BaBar physics program is very limited. very limited.

B J/KL J/l+l- High momentum KL !!!

In discussions with AWG convenors, processes with In discussions with AWG convenors, processes with KKL L final states have final states have usually not been listed as part of the planned physics program.usually not been listed as part of the planned physics program.

There may be analyses in which it is useful to veto There may be analyses in which it is useful to veto KKLL’s’s in order to improve in order to improve the correspondence between missing energy and neutrino momentum. We the correspondence between missing energy and neutrino momentum. We need to investigate this. What is efficiency at low p???need to investigate this. What is efficiency at low p???

My own view is that we should try to maintain some level of My own view is that we should try to maintain some level of KKLL efficiency efficiency unless this results in measurable degradation in muon ID performance. unless this results in measurable degradation in muon ID performance. For any new detector design, we should monitor its effect on the For any new detector design, we should monitor its effect on the benchmark decay benchmark decay BB J/ J/KKLL . .

status report on ifr physics issues

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