Deghosting for the CPS


  • Presentation for feb 26 (ppt)
  • Matching MC tracks to CPS 3D clusters
  • Matching real tracks to CPS 3D clusters


    Matching MC tracks to CPS 3D clusters


    Isolation

    The isolation term is defined as the number of tracks within a 5 cm radius of the test electron track. There are 4 sets of plots tested with deghosting parameters of 0.4, 0.5, 0.6 and 1.0. The first set is the ratio of electron matching efficiency with deghosting on/ deghosting off vs number of adjacent tracks, the second is electron matching efficiency vs number of adjacent tracks, the third is the percent of fakes removed and the fourth is efficiency vs pT.

  • 3200 ttbar p13.03.00 MC events
  • 4750 ttbar p09.08.00 MC events
  • 2000 ttbar p04 MC events

    MC tables of 3D clusters and matches kept for different deghostpwrs

    = p13.03.00 MC , PTCUT = 1.4GeV, DRCUT = 1.5cm
    ===================================================================
    deghostpwr | 3D clusters kept |  matches kept | > 20GeV  | < 20GeV   
    ========== TTB 3200 events, 1845 tracks > 1.4 GeV =================
      off      |    990,009       |  1684         |    654   |   1030
      0.2      |    982,887       |  1684         |    654   |   1030
      0.3      |    779,274       |  1675         |    654   |   1021
      0.4      |    527,933       |  1640         |    652   |    988
      0.5      |    380,572       |  1604         |    650   |    954
      0.6      |    297,029       |  1573         |    648   |    925
      0.8      |    212,612       |  1532         |    643   |    889
      1.0      |    173,831       |  1493         |    640   |    853
      1.5      |    135,611       |  1422         |    633   |    789
      2.0      |    122,765       |  1387         |    632   |    755
     10.0      |    108,861       |  1324         |    627   |    697
    
    
    = p09.08.01 MC , PTCUT = 1.4GeV, DRCUT = 1.5cm
    ===================================================================
    deghostpwr | 3D clusters kept |  matches kept | > 20GeV  | < 20GeV   
    ========== TTB 4750 events, 2903 tracks > 1.4 GeV =================
      off      |  1,929,470       |  2439         |    916   |   1523
      0.2      |  1,916,045       |  2439         |    916   |   1523
      0.3      |  1,529,523       |  2431         |    916   |   1515
      0.4      |  1,044,277       |  2412         |    916   |   1496
      0.5      |    755,042       |  2379         |    916   |   1463
      0.6      |    588,848       |  2307         |    912   |   1395
      0.8      |    419,540       |  2212         |    909   |   1303
      1.0      |    340.908       |  2142         |    901   |   1241
      1.5      |    264,306       |  2023         |    901   |   1122
      2.0      |    237,864       |  1968         |    898   |   1070 
     10.0      |    209,583       |  1863         |    884   |    979
     
    
    = p04 MC , PTCUT = 1.4GeV, DRCUT = 1.5cm
    ===================================================================
    deghostpwr | 3D clusters kept |  matches kept | > 20GeV  | < 20GeV   
    ========== TTB 2000 events, 1059 tracks > 1.4 GeV =================
      off      |  1,117,238       |  1010         |    403   |    607
      0.2      |  1,100,952       |  1010         |    403   |    607
      0.3      |    805,789       |  1004         |    403   |    601
      0.4      |    519,334       |   988         |    403   |    585
      0.5      |    366,808       |   977         |    403   |    574
      0.6      |    284,151       |   948         |    402   |    546
      0.8      |    202,478       |   905         |    402   |    503
      1.0      |    165,201       |   881         |    402   |    479
      1.5      |    129,272       |   845         |    400   |    445
      2.0      |    117,356       |   824         |    396   |    428
     10.0      |    104,624       |   798         |    392   |    406
    ========== ZEE 2000 events, 2247 tracks > 1.4 GeV =================
      off      |    108,618       |  2220         |   1964   |    256
      0.2      |    108,135       |  2220         |   1964   |    256
      0.3      |     95,354       |  2220         |   1964   |    256
      0.4      |     78,354       |  2219         |   1964   |    255
      0.5      |     66,275       |  2218         |   1964   |    254
      0.6      |     58,473       |  2218         |   1964   |    254
      0.8      |     49,496       |  2217         |   1963   |    254
      1.0      |     44,577       |  2217         |   1963   |    254
      1.5      |     39,384       |  2212         |   1959   |    253
      2.0      |     37,394       |  2208         |   1957   |    251
     10.0      |     34,908       |  2204         |   1956   |    248
    

    Problem solved! Here are plots of dphi vs. q/pt and electron pt match before and after a correction for the dependence of dphi on q/pt. (drcut = 1.5 cm)


    3200 ttbar p13.03.00 MC events (SAM dataset mc_p13.03.00_ttb_reco)
    Efficiency with deghosting on / efficiency with deghosting off vs number of adjacent tracks


    Electron matching efficiency vs number of adjacent tracks


    Percent of fakes removed


    Electron matching efficiency vs pt


    4750 ttbar p09.08.00 MC events (SAM dataset gardnerj_mc_p09_ttb)
    Efficiency with deghosting on / efficiency with deghosting off vs number of adjacent tracks


    Electron matching efficiency vs number of adjacent tracks


    Percent of fakes removed


    Electron matching efficiency vs pt


    2000 ttbar p04 MC events
    Efficiency with deghosting on / efficiency with deghosting off vs number of adjacent tracks


    Electron matching efficiency vs number of adjacent tracks


    Percent of fakes removed


    Electron matching efficiency vs pt



    Matching real tracks to CPS 3D clusters


    Goal:

    Using electron tracks from real data, find out how effectively my deghosting routine removes extra (ghost) 3D clusters while keeping matches to tracks.

    Procedure:

    A sample of 3212 Z->ee candidates (1288 useable), reconstructed using p11.11.00, was used. The selection cuts require

    EITHER:

    • one central (abs(eta) < 0.8) EM object with pt > 20 GeV and another with pt > 15 GeV at any eta
    • or 2 central EM objects with pt > 15 GeV
    AND all of:
    • EM fraction > 0.9
    • isolation > 0.15
    • abs(id) <= 12

    It was also the case that many of these events were in runs were the CPS was not fully instruments. All runs <= 151831 were cut leaving 1288 events.

    From this Z->ee sample, single electron cuts were applied to all EM objects:

    • emobj.is_in_fiducial()
    • pT > 20 GeV
    • isolation < 0.15
    • EM fraction > 0.9
    • HMx8 < 20
    In the Z->ee sample, there were:

  • 709 total EM objects passing these cuts:
  • 168 of these also had a track match

    These EM objects are matched to CPS 3D clusters. Based off calorimeter position information, a one sigma match is approximately 0.9 cm. Matches were done based on a 2 sigma dr cut. In the table, is the deghost parameter tried, total number of clusters kept, total number of em objects matched and number of em objects also matched to a GTR 401 track kept.

    = REAL ZEE candidates, p11.11.00, 3212 events(1288 good) ===========
    = 709 em objects in fiducial region, 168 with a track ==============
    == cps position based on calorimeter, drcut = 1.8(~ 2sigma) ========
      deghostpwr   clusters kept   em objects matched   with a track
      off           587,037            562                   144              
      0.2           579,749            562                   144
      0.3           429,390            558                   144
      0.4           282,697            539                   142
      0.5           204,853            533                   142
      0.6           162,167            520                   140
      0.8           119,131            508                   139
      1.0            97,743            498                   138
      1.5            74,621            478                   133
      2.0            65,929            461                   131                      
     10.0            55,740            406                   122  
    
    
    For those em objects with a track match, matching was also done based off track position. For GTR tracks, one sigma is estimated at 0.5 cm. Matching based on 2 and 3 sigmas were tried.
    
    == cps position based on gtr 401 tracks ============================
      deghostpwr   clusters kept   drcut = 1.0           drcut = 1.5
      off           587,037            147                   154             
      0.2           579,749            147                   154
      0.3           429,390            147                   154
      0.4           282,697            146                   154
      0.5           204,853            146                   154
      0.6           162,167            145                   151
      0.8           119,131            143                   151
      1.0            97,743            142                   151
      1.5            74,621            133                   145
      2.0            65,929            128                   142                    
     10.0            55,740            118                   132                 
    
    

  • View of all events having tracks with no matching 3D cluster (x's represent tracks and circles are 3D cluster centroids with 1.5 cm radius.)
  • The electron track matching efficiency and total 3D clusters were recorded for different deghostpwr values.

    All track matches were kept at deghostpwr = 1.0 with 82% of 3D clusters removed.

  • Comparison: deghosting off vs. deghostpwr = 1.0 (x's represent tracks and circles are 3D cluster centroids with 1.5 cm radius.)
  • The 10 tracks that were lost at deghostpwr = 2.0 were compared at deghostpwr = 2.0 vs. off.

  • Comparison of lost tracks before with deghosting off and after with deghostpwr = 2.0 (x's represent tracks and circles are 3D cluster centroids with 1.5 cm radius.)