Event-of-the-Day

Fri 2 May 2003

Photo of the event-of-the-day for Fri 2 May, 2003.

Today's event of the day is a MC event that required me to make some extra checks in creating windows. The problem was with a high angle decay positron for a muon that stopped before the target PC's. The decay positron wound around in the detector without hitting any PC's until 60-70 ns later. This problem left a bunch of DC hits from this high angle decay in the previous window since they were so much earlier than the PC times which created the window. The fix was to extend windows by looking for more than 5 DC hits per 50 ns bin before the PC hits -- for windows seperated by > 500ns. A photo of the event described above with the fix to windowing is attached (run1event33479_0.ps) Another issue that I have come accross, which also has to do with these really high angle decays that stay in the detector for a long time, is that I can misclassify them as being PC overlap events. I can reduce the number of events misclassified this way by looking at the PC time of flight. Attached is a plot of the time of flight calculated from the earliest PC times in each PC stack, VS. the Monte-Carlo cosine theta (

pctofvsmccosth.gif ).


With these fixes, my classification seems to behave better.  The MCTR
info for the event described above is:
 ------ run:   1  event:   33479  geant seeds:   190836906  12
 Have   10  MonteCarlo tracks
MCTR: itrack=  1 pid= 65 istop= 0
                 V=    0.5840   -1.2774 -300.0000
                 P=     0.092     0.165    29.407 Q= 1
                 T=   -27.4 pmag=  29.408 cost=0.999979
MCTR: itrack=  1 pid= 65 istop= 1
                 V=   -0.1143   -1.4163   -1.6391
                 P=     0.000     0.000     0.000 Q= 1
                 T=    19.5 pmag=   0.000 cost=    -NaN
MCTR: itrack=  2 pid=  2 istop= 0
                 V=    0.5919   -3.1803 -300.0000
                 P=     0.021     0.333    29.484 Q= 1
                 T=   751.0 pmag=  29.486 cost=0.999936
MCTR: itrack=  2 pid=  2 istop=98
                 V=    0.2171   -1.8027  150.7270
                 P=    -0.942    -1.014    28.725 Q= 1
                 T=   766.1 pmag=  28.758 cost=0.998841
MCTR: itrack=  3 pid=  2 istop= 0
                 V=   -0.1143   -1.4163   -1.6391
                 P=   -44.995    21.919    -1.396 Q= 1
                 T=  1489.8 pmag=  50.069 cost=-.027887
MCTR: itrack=  3 pid=  2 istop= 5
                 V=    0.8588    0.6439  -80.8848
                 P=   -31.933    17.202   -12.811 Q= 1
                 T=  1633.9 pmag=  38.467 cost=-.333033
MCTR: itrack=  5 pid=  3 istop= 0
                 V=   11.2955    7.0449   10.3981
                 P=     0.424    -0.202     0.359
                 Q=-1 T=  1588.4 pmag=   0.591 cost=0.608025
MCTR: itrack=  5 pid=  3 istop= 2
                 V=   11.3809    7.1510   34.3938
                 P=     0.000     0.000     0.000 Q=-1
                 T=  1594.6 pmag=   0.000 cost=    -NaN
MCTR: itrack=  8 pid=  3 istop= 0
                 V=    0.3850   -0.4583 -103.1620
                 P=     0.372    -0.030     0.126 Q=-1
                 T=   757.6 pmag=   0.394 cost=0.320119
MCTR: itrack=  8 pid=  3 istop= 2
                 V=    0.3854   -0.4637 -103.1630
                 P=     0.000     0.000     0.000 Q=-1
                 T=   757.6 pmag=   0.000 cost=    -NaN

My MC classification using MCTR and MCSP info is:
 nMCWindows:   7
 MCWindow=  1  T0=  0.000000  nMu,nDK,nBeame,nDeltas  0  0  0  0
Min,MaxPl=  0  0  Type=  5  (Empty)
 MCWindow=  2  T0=  7.00000  nMu,nDK,nBeame,nDeltas  1  0  0  0
Min,MaxPl=  1  27  Type=  1  (Muon)
 MCWindow=  3  T0=  0.000000  nMu,nDK,nBeame,nDeltas  0  0  0  0
Min,MaxPl=  0  0  Type=  5  (Empty)
 MCWindow=  4  T0=  762.000  nMu,nDK,nBeame,nDeltas  0  0  1  0
Min,MaxPl=  1  56  Type=  4  (Beam
Positron)
 MCWindow=  5  T0=  0.000000  nMu,nDK,nBeame,nDeltas  0  0  0  0
Min,MaxPl=  0  0  Type=  5  (Empty)
 MCWindow=  6  T0=  1495.00  nMu,nDK,nBeame,nDeltas  0  1  0  1
Min,MaxPl=  1  34  Type=  9  (Upstream Decay
(Scatter back downstream))
 MCWindow=  7  T0=  0.000000  nMu,nDK,nBeame,nDeltas  0  0  0  0
Min,MaxPl=  0  0  Type=  5  (Empty)
 OVERALL MC EVENT TYPE=  13

And the classification using just TDC information is:
 EventType:   13  (Time DC Overlap Scatter Cleaned)
 Windows:   7
  window  1, T0= -10000., DC window= -10000.    -43., hits PC,DC=   0
0, Min,MaxZ=   99.0  -99.0, type=   5
(Empty)
  window  2, T0=      7., DC window=    -43.    712., hits PC,DC=   6
29, Min,MaxZ=  -59.7   -4.6, type=   1
(Muon)
  window  3, T0=    712., DC window=    712.    712., hits PC,DC=   0
0, Min,MaxZ=   99.0  -99.0, type=   5
(Empty)
  window  4, T0=    762., DC window=    712.   1445., hits PC,DC=  13
45, Min,MaxZ=  -59.7   59.8, type=   4
(Beam Positron)
  window  5, T0=   1445., DC window=   1445.   1445., hits PC,DC=  26
223, Min,MaxZ=  -59.7   -5.0, type=   5
(Empty)
  window  6, T0=   1495., DC window=   1445.   2995., hits PC,DC= 102
135, Min,MaxZ=   -4.6   29.8, type=  10
(Downstream Decay (Scatter back upstream))
  window  7, T0=   2995., DC window=   2995.  20000., hits PC,DC=   0
35, Min,MaxZ=  -49.4   29.4, type=   5
(Empty)

-Blair

Last modified by Blair Jamieson.