Overview of Muon POG tasks

Work in progress, under construction

This page shows an overview of muon POG tasks and the manpower situation This is a wish-list for developments in muon reconstruction and id during LS1. As a complement see Muon Reconstruction Workshop that has been held as part of the Muon Workshop in October 2011, talk by G. Abbiendi at Offline Coordination Meeting in Nov 2013, and talk by S. Goy Lopez at PPD meeting Nov 2013

For trigger see summary talk by D. Trocino at TSG Workshop Dec 2013

For Phase II Upgrade studies see talk by D. Trocino at Future Analyses meeting Nov 2013

Green color means DONE , blue color means BEING DONE , black means that there is either none working on this or that there has not been any recent presentation on the particular subject.

If you are interested in any of these tasks, independently of its color, please contact muon pog conveners: cms-pog-conveners-muo@cernNOSPAMPLEASE.ch

For tasks on muon DPG local reconstruction see

  • Local Reconstruction
    • RPC
      • To include masked strips in DB to do a more precise reclusterization.
      • RPC Alignment.
      • RE4 in DQM and reconstruciton Local and Global.
      • Check error assignment in endcaps
    • DT
      • Full understanding of mean timer (in particular chi2 of STA in overlap region)
      • Introduce dead channels to simulation/reconstruction
      • Use muon RECO information on MB4 to correct time propagation along the wire
      • Study vdrift parameterization
      • Study possibility of applying quality cuts to segments in MB1 W+/-2
      • Combine all stations to produce a Super-z segment, could help to distinguish among different possibilities
      • Optimize hit errors given in input to the segment fit (now set to constant)
      • Study possibility of special treatment in case of showering muons
    • CSC
      • Ensure local reconstruction works correctly with LS1 upgrade hardware
      • Review parameters of UF rechit algorithm.
      • Review treatment of rechits and segments when showering occurs.
      • Remove crosstalk conditions data from rechit reconstruction.
      • Study influence of noise on rechit reconstruction.
      • General code cleanup for both CSCRecHitD and CSCSegAlgoST
      • Reintroduce possibility of using Gatti fit to obtain position rather than parameterization
      • Continue studies of rechit ‘charge’, and of rechit and segment time
      • Study possibility of using Hough-Legendre transformations

Development Tasks

Reconstruction

For Done tasks see

Task Available people Task Priority Comment
Implement a muon object independent of DT/CSC
  ? A result of global fit only with Tracker and RPC
Development M. Kim, D. Kovalskyi Normal DONE

Stand Alone muons

Task Available people Task Priority Comment
Improve Seeding
  ? Recover inefficiencies in HLT and Offline reco for close-by muon pairs
  ? Optimal use of upgraded CSC in the relevant regions
H. Brun, J. Mejia, A. Almada High SAME FOR HLT. Regarding inefficiencies for close-by muons see original talk by F. Fiori and S. Zenz. Another talk by F. Fiori shows that the problem originates in L2(STA) seeding. Regarding inclusion of post-LS1 muon detectors in seeding see this talk by H. Brun, J. Mejia, A. Almada
Track Fitting
  ? Study adding smoothing step as last step of Kalman filtering. No refit is currently applied for smoothing. It improves momentum resolution and provides correct track chi2, but found to be unstable and decrease efficiency, further studies needed
  ? Understand the reason for the eta flip after update at vertex and fix it properly. For now only a protection is added when STA and STA updated at vertex have opposite eta sign
  High SAME FOR HLT. Regarding addition of smoothing step see here for potential improvements and this link for the associated efficiency drop.On eta flip see talk by A. Everett here, and S. Dutt here
STA reco for displaced and delayed muons
  ? Include timing corrections and possibly specialized seeding algorithm
  ? Study biases wrt. BS
DT DPG, M. de Mattia, J. Alimena High Talk by M. De Mattia
Reoptimization of SteppingHelix propagator
  ? Reduce the propagation time without ruining resolution and efficiency
A. Svyatkovskiy, S. Krutelyov Normal SAME FOR HLT Talk by A. Svyatkovskiy
Understand differences between data and MC resolution (~10%)
  ?This difference has been observed in MUO-10-004 (Fig. 22). According to studies of D. Trocino and N. Amapane it does not seem to depend on alignment scenario
  Normal  
Cleaning up the RecoMuon collection
  ?This concerns duplicates entering the collection from different types of reconstruction (e.g. STA with or w/o update at vertex)
  Normal  
Study possibility of using the SIMPLEX method in standard STA.
  ? As it is not iterative it might be more stable than the kalman filter (for estimating pt, track parameter, estabilize the fit)
  Normal  
Try using RPC hits to confirm segments in 1st (or 4th) station
  Normal  
Study the idea of having tighter pattern recognition at the initial step (as done in the different iterative steps in inner tracking)
  Normal  

Global muons

Task Available people Task Priority Comment
Matching between tracker tracks and STA tracks
  ? Detailed study of the matching in the presence of high pile-up and possible re-optimization. Revisit matching criteria to reduce number candidates per standalone muon. Possibly reduce size of region of interest with improved use of vertex information
  ? Optimize algorithm for close-by muons
  ? Study stability of local chi2 under misalignment
Purdue High SIMILAR FOR HLT
Full use of APEs in STA and GLB fits
  ? Retune of TuneP and DYT
  ? Pulls of global (re)fits at high pT suffer from large irregularities (see e.g. MUO-10-004 Fig. 23) which seems to be caused by underestimation of segment uncertainties in the fit; the inclusion of APE's seems to help curing the problem (see talk by J. Tucker here)
  High Results by Alexey show good behavior of fit with APES when using a realistic misalignment scenario (see here). Muon Alignment group in charge of providing final APEs and continue developments of alignment procedure.

High pt reconstruction studies
  ? Consolidate current use of multiple refits.
  ? Full use of DYT (Dynamic Truncation algorithm) A prerequisite is the use of APEs.
  ? When APEs ready and DYT in place study possibility of input DYT in PF momentum assignment algorithm
  ? Investigate alternatives to current approaches,ex try GSF, exclude stations with high multiplicity of hit clusters (EM showers) etc
P. Traczyk, D. Pagano, M. Bachtis High For current status of DYT see talk by D. Pagano here and latest here
Low pt studies
  ? Refit subset of tracker muons with muon hits.
  Normal  
Study contribution of GEM on the muon reconstruction
  ? Study effect on pt resolution and charge mis assignment for STA and GLB muons
  ? Use of GEMs in STA Seeding, TEV refits, Tracker Muons and create GEM ID
GEM community High See talk at muon POG by C. Calabria and S. Krutelyov here and past talk of M. Maggi here

Tracker muons

Task Available people Task Priority Comment
Study/re-optimize Muon Tracker arbitration for high pile up and 25 ns scenario
  ? Study whether using RPC information for arbitration could help
D. Kovalskyi High  

Identification

For Done tasks see

Task Available people Task Priority Comment
Implement standard Muon id selectors in CMSSW
  ? Create a selector for Loose, Soft, Tight and HighPt id
  ? Make a reference list of events to be used for crosschecks
M. Bachtis High  
Finish the tuning of the HighPt id for the tracking inefficiencies introduced in 52X
  ? Study alternatives to nLayer>8 cut
P. Traczyk High PAG to help: EXO NewTuneP algorithm was developed that allowed changing back the cut on nLayer<5 while adding a dpt/pt<3 cut. See this and this talks by Piotr
PF muon id
  ? Quantify the proportion of PF muons selected through different branches of the decision tree
    ? how many Global, Tracker and Standalone muons are selected depending on the event topology
  ? Study the differences between Tight muons and PF muons with tight quality cuts
    ? how many non-common events are selected, what are their particular features?
M. Bachtis High PAGs to help: any DONE but some effort on documentation welcome
Improve the method of extracting fake rates
  ? Use fit parameters instead of counts
M. Mooney High PAG to help: BPH
RPC Muons
  ? Study of efficiencies: compare the efficiency to that from the standard Loose Muon selection
  ? Study of fake rates
RPC DPG Normal See talk by J. Goh here

Task Available people Task Priority Comment
Check whether HighPt id needs to be retuned when new APEs are activated
P. Traczyk High PAG to help: EXO
PF Muon ID
  ? Fully document the current PF id decision tree. Quite some progress has been done on this recently (see done tasks) but still some extra effort on the documentation would be welcome
  Normal Recent talks by M. Bachtis here and here
Tracker Muons
  ? Understand pull/residual differences between data and MC (~10%, MUO-10-004 sec. 4.3, Figs. 8 and 9) This discrepancy strongly contributes to data/MC scale factors of Tracker Muon based muon id efficiency esp. in barrel (see Fig. 12 left in MUO-10-004)
  ? Systematic comparison of selectors. There is a plethora of selectors available in http://cmssw.cvs.cern.ch/cgi-bin/cmssw.cgi/CMSSW/DataFormats/MuonReco/interface/MuonSelectors.h; a systematic comparison of their performance could contribute to improvements in muon id (some of them are used in GED)
  Normal PAG to help: SUS
RPC Muons
  ? Study of efficiencies and fakes mostly finished (See done tasks)
  ? Study of track-to-hit matches: residual and pull, bunch crossing
  ? Apply the RPC-standalone seed to track matching (RPC-standalone seed is a dedicated seed which uses only the RPC hits as input)
  Normal RPC DPG
Study possible use of HO for muon identification
D. Kovalskyi Normal  
Finish retuning of SoftID
I. Kratschmer Normal Last talk by Ilse
Study reconstruction and id efficiency for high pT muons
  ? Try using high mass DY events or boosted Zs with full 2012 data
  ? Use cosmics data and MC. See past studies by I. Belotelov here Systematics specific to cosmics needs to be disentangled (new cosmics MC should be helpful)
C. Bernardes, A. Santos High PAG to help: EXO. See talk by Angelo on efficiency calculations with DY events.
Use of timing information in muon quality selectors
  ? Possible use of specific local reconstruction in DT for OOT muons
  Normal To be followed up with DT DPG. PAG to help: EXO. See this talk by P. Traczyk
Understand if we need a specific muon id for muon veto and jet disambiguation
  Normal PAG to help: SUS
Study the systematics of the Tag&Probe method
  ? Repeat checks done in MUO-10-004 with full statistics
  ? Understand how well we can trust that the efficiency measured @Z is valid for high pT. Study fit quality of TnP method in high pt bins .
  ? Use alternative methods to measure id efficiency (e.g. cosmics)
  ? Study id efficiency vs distance to jets, vs. muon distance etc.
H. Brun, G. Ortona, S. Stoynev, A. Svyatkovskiy, I. Josa Normal PAGs to help: any. Talk by I. Josa and talk by H. Brun on systematics of TnP fits .

Momentum assignment

For Done tasks see

Task Task type Available people Task Priority Comment
PF muon momentum assignment
  ? Fully document the current PF muon momentum assignment decision tree
  ? Propagate the uncertainty on pT measurement into PF muon
  ? Introduce high pt reconstructors as a part of PF momentum assignment
    ? study the performance of PF momentum assignment for high pt muons
  ? Quantify the proportion of PF muons with pT from different fits
    ? how often is Global, Tracker and Standalone pT used depending on the event topology
  ? Study the differences between reco::Muons pT and PF muon pT
    ? study in detail events with large difference in pT
  ? Improve the PF momentum assignment decision tree
    ? use benchmark plots to qualify performance
  ? study the correlation of post-cleaning and id tracker quality cuts
    ? compare the effect on far pT tails_
  ? Study implications of post cleaning for different topologies
    ? _Important is to study the effect of post-cleaning on topologies with natural MET, part of post cleaning is based on MET minimization (see talk by P. Janot here)
M. Bachtis High PAGs to help: any Mostly DONE but some effort on documentation welcome . Recent talks by M. Bachtis here and here

Task Available people Task Priority Comment
Finish the study of fully-segment based fit (in 52X) using APE’s
  ? To Be Done: Use updated APE's from last muon alignment
A. Svyatkovskiy High PAG to help: EXO
PF muon momentum assignment
  ? Fully document the current PF muon momentum assignment decision tree
  ? Introduce DYT when ready as a part of PF momentum assignment (other HighPT refits included already)
M. Bachtis High PAG to help: EXO Mostly DONE (see done tasks) but some effort on documentation welcome

Momentum scale and resolution

For Done tasks see

Task Available people Task Priority Comment
Understand implications of muon alignment on high pt momentum resolution
P. Traczyk High * Momentum scale and resolution strongly depends of the quality of the muon alignment (see talks by P. Traczyk, e.g. here) Latest explanation on the muon alignment in MC has been given here. PAG to help: EXO
Rochester method for momentum scale correction
  ? Apply the method to 2012 data
J. Han, A. Bodek High  
MuScleFit method at Z peak
  ? Finish studies for 42X and 44X including MC and full acceptance
  ? Continue studies with 2012 data
  ? Finish systematic studies
S. Casasso, E. Migliore High  

Task Available people Task Priority Comment
Rochester method for momentum scale correction
  ? Finish systematic studies
J. Han, A. Bodek High  
MuScleFit method at Z peak
  ? Finish systematic studies
S. Casasso, E. Migliore High See last talk by Ernesto
MuScleFit method at J/psi peak
  ? Make studies with 2012 data
C. Dozen, G. Gokbulut, M. de Mattia Normal  
SIDRA method
  ? Finish studies for 42X and 44X
  ? Look at 2012 data
  Normal  
Understand non-Gaussian part of the resolution at intermediate pTs
  ? Study events where different reconstructors give different pT
  ? Use cosmics and use large statistics MC
  Normal PAG to help: EXO
Endpoint method
  ? Update general and endpoint studies with 2012 data (see talks by N. Kypreos e.g. here)
  ? Improve precision of cosmic endpoint. The precision obtained is limited (~5%/TeV) due to low statistics. Precision of cosmics endpoint could be improved by carefully relaxing the selection criteria.
  High PAG to help: EXO
Better understanding of momentum resolution at high pt
  ? Compare resolutions measured with collision and cosmic muons in order to understand how much can we trust the resolution from cosmics
  ? Measure resolutions with cosmic MC
  ? Need deeper understanding of effects of misalignment in order to reach ultimate resolution at high pT according to TDR (9% mass resolution at 5 TeV mumu mass)
  ? Develop methods to measure high pt resolution in endcaps
  ? Assess impact of uncertainties on un-aligned coordinates (in part. on Rotation angles in the bending plane) in STA and GLB fits
A. Guth, M. Endres High l PAG to help: EXO. See talks by J. Tucker e.g. here. Here latest studies by M. Endres, A. Guth on resolution with cosmics
Insert momentum scale corrections in the database as standard part of the global tag
Together with AlCa group Normal PAG to help: EXO

Isolation

Task Available people Task Priority Comment
Advanced methods of isolation measurement
  ? Tune working points of cut based radial isolation
    ? study the PU dependence of different working points
  ? Simplify the MVA isolation algorithm
    ? study the use of dBeta PU correction instead of rho
  ? implement these algorithms in CMSSW
S. Folgueras Normal PAGs to help: HIG, any
Quantify the systematics of isolation efficiency measurements
  ? Compare T&P and LKT
  ? Fully understand systematics at low pt
  ? Perform T&P syst. studies similar to those done for id in MUO-10-004
G. Ortona, P. Verwillingen High PAGS to help: SMP, HIG, any
Study and retune isolation definitions for higher energy and pile up
  ? Optimize cone sizes, working points and pile up corrections, improve uniformity vs pile up
  High PAGS to help: any
Improve uniformity
  ? Improve uniformity vs. pT (The efficiency of currently used algorithms (all relative isolation) decreases at low pT; one possibility could be to combine the relative isolation with absolute isolation at low pT)
  ? Improve uniformity vs vs eta (first step done: here)
  High PAGS to help: any

Trigger

For trigger see summary talk by D. Trocino at TSG Workshop Dec 2013

Task Available people Task Priority Comment
Understand and cure the L3 PU dependent inefficiency in 0.9<|eta|<1.5 region
  ? Find the origin of the inefficiency (seeding, reconstruction)
  ? Cure the inefficiency (without increasing the rate)
PURDUE High PAGs to help: any. For reference see plots by S. Walsh and B. Klein data, MC
In general make L3 more robust against PU
  ? Review current algorithms, develop new ones
  ? Re-optimize error matrix
  ? Optimize L3 matching filters
PURDUE Normal need to watch the effect on offline
Revise HLT tracking for muons
PURDUE High PAGs to help: any
L2 efficiency for close muons
  ? Debug the seeding for close muons
H. Brun, CINESTAV High PAG to help: BPH. See talks of F. Fiori and S. Zenz here and another talk by F. Fiori here shows that the problem might originate in L2(STA) seeding
Isolation tuning
  ? Use PF isolation online
S. Fiorendi Normal PAGs to help: any
Tuning of L2/L3 quality cuts
  ? Tune current and add new quality cuts (a la offline)
  Normal need to watch the effect on offline
Improvements in L2 reco
  ? Use segment fit at L2 (a la offline)
  ? Try smoothing in refit (see here for potential improvements and this link for the associated efficiency drop
  Normal need to watch the effect on offline
Use of Tracker Muons for SingleMu paths
J. Sekaric Normal PAGs to help: any
More detailed studies of triggering on high PT muons
  ? Study possibility of using TeV refits in trigger
  Normal PAGs to help: any
Quantify the systematics of trigger efficiency measurements
  ? Perform T&P syst. studies similar to those done in MUO-10-004
  ? Check T&P efficiencies with forcing the tag to be in different detector (link)
S. Stoynev Normal PAGS to help: any
Double muon trigger purity vs. PU
  ? We see increase of double muon trigger cross sections with PU which needs to be cleaned up without significant loss of efficiency
  Normal PAGs to help: any
L2 purity as a function of L1 threshold
  ? We observe an increase of trigger rates depending of the L1 threshold (rate) which indicates that L1 does better job rejecting certain classes of background
  Normal PAGs to help: any

Fast simulation

Task Available people Task Priority Comment
Various improvements: punch-trough, mu energy deposits in calorimeters, bremsstrahlung
  Normal PAGs to help: any

GED (Global Event Description)

Task Available people Task Priority Comment
Study the momentum assignment in dense environment
  Normal PAGs to help: SUS. After recent changes in tracking and PF momentum assignment need to remake old studies focused on comparisons of tracker track and GED muon momentum at intermediate pT for isolated muons (talks by C. Battilana here and talk by C. Bernet here)
Further study and improve the recovery of momentum lost due to FSR (and EM showering)
  ? Partially done in PF algo
  ? Might need to use full event information, and be analysis-specific
  Normal See talk by P. Janot here

Tracking (together with TRK POG)

For Done tasks see

Task Available people Task Priority Comment
Outside-in seeding of muon tracks. DONE in 61X
  ? After recent changes (52X) in tracking the average number of layers/hits used in the track fit has decreased for muons
  ? The idea is to introduce a specific tracking for muons based on outside-in seeding using information from muon detectors
G. Petrucianni Normal PAGs to help: any. See here for latest developments

Task Available people Task Priority Comment
Study further tracking developments (MVA) using muon detectors
  ? See ideas outlined in the talk by K. Stenson here
  Normal PAGs to help: any.

Continuous tasks

Muon reconstruction and identification

Task Task type Available people Task Priority Comment
Software coordination: integration, validation and publication of changes Continuous M. Bachtis, R. Bellan Normal  
Global muon reconstruction: maintenance, debugging, bug fixes On-demand Purdue Normal  
Standalone muon reconstruction: maintenance, debugging, bug fixes On-demand D. Trocino Normal Need 2nd expert for continuity
Tracker muon reconstruction: maintenance, debugging, bug fixes On-demand D. Kovalskyi Normal Need 2nd expert for continuity

Muon reco+id performance

Task Task type Available people Task Priority Comment
Measure efficiency of standard muon selections with T&P on J/ψ and Z peaks On-demand Go fast forward I. Josa Mutuberria, I. Kratschmer, C. Botta, G. Petrucciani Normal  
Measure fake rates of standard muon selections with exclusive samples of π, K and p On-demand M. Mooney Normal  
Measure reco/id efficiency for high-pT muons using cosmics data and MC On-demand/Development need a person to replace J. Tucker Normal a way to validate MC-based high-pT muon efficiency
Measure reco/id efficiency for high-pT muons using pp data and MC On-demand/Development C. Bernardes, A. Santos Normal  

Go fast forward - short learning phase (no/little previous expertise required)

Muon isolation

Task Task type Available people Task Priority Comment
Measure reference isolation efficiencies On-demand Go fast forward C. Albajar, I. Josa Mutuberria Normal  
Go fast forward - short learning phase (no/little previous expertise required)

Muon momentum scale & resolution

Task Task type Available people Task Priority Comment
Calibration of p scale and measurement of the p resolution On-demand J. Han, A. Bodek, S. Casasso, E. Migliore High  
Evaluate momentum scale at high pT (cosmic endpoint method) On-demand need a person to replace N. Kypreos Normal  
Measure resolution of various reconstructors at high pT using cosmics On-demand M. Endres, A. Gueth Normal  

Certification/Validation/DQM

Task Task type Available people Task Priority Comment
Release validation with MC Continuous R. Vilar, A. Perotta, J. Cuevas (HLT), A. George (ID) High Need one person for coordination of validation activities
Data certification; release validation on data; offline DQM Continuous A. Calderon Tazon, C. Jorda Lope, S. Folgueras Normal  
Improve DQM: improve PU monitoring, put (cosmic) high pt resolution into DQM, muon alignment validation, add more selectors, improve GED validation tool for muons Development A. Calderon Tazon, S. Folgueras Normal  
Automate certification process Development J.R. Castineira Normal Important to avoid oversights and release load on experts
Automate validation process Development   Low Ditto

Tools

Task Task type Available people Task Priority Comment
Cosmic identification tool development Development H. Yoo Low  
Beam-halo identification tool development Development R. Remington Low  
T&P package: maintenance and bug fixes On-demand G. Petrucciani, C. Botta Normal Need more experts for continuity
T&P package: development Development G. Petrucciani, C. Botta Normal  
MuScleFit maintenance On-demand E. Migliore, S. Casasso Normal  
SIDRA maintenance On-demand   Low  
Kink-finder: maintenance and bug fixes On-demand G. Petrucciani Low  
Shower id variables: further studies Development A. Svyatkovskiy Low  

HLT

Task Task type Available people Task Priority Comment
Coordination, menu survey Permanent D. Trocino, C. Battilana, H. Brun High  
Level-3: Maintenance, debugging, bug fixes On-demand   High Purdue
Level-2: Maintenance, debugging, bug fixes On-demand D. Trocino High Same person as STA; need 2nd expert
Trigger efficiency measurements with T&P On-demand Go fast forward I. Josa Mutuberria, P. Verwilligen, S. Chibba Normal  
Trigger purity measurements On-demand Go fast forward Y. Choi, Y. Cho Normal  
HLT validation On-demand J. Cuevas High  
Improvements in HLT validation and DQM Development J. Cuevas, S. Folgueras Normal  
Trigger isolation efficiency measurements On-demand Go fast forward need a person Normal  
Go fast forward - short learning phase (no/little previous expertise required)

Other

Task Task type Available people Task Priority Comment
Production of MC samples On-demand A. Fanfani Normal  
Data transfer and management of group space at dedicated muon Tier-2's On-demand A. Fanfani Normal  
Fast simulation: punch-through outside tracker, μ energy dep. in calorimeters, bremsstrahlung Development A. Perotta Low  

Contacts

-- SilviaGoyLopez - 08 Nov 2013

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