Event-of-the-Day

Thu 8 May 2003

Photo of the event-of-the-day for Thu 8 May, 2003.

Today's event of the day is a MC version of yesterday's event. The event is a muon decay in flight which, unlike yesterday's event, decayed before entering the upstream PC's. This event and yesterday's event made me think about how to define a beam positron versus a decay positron. In the code we have been calling beam positrons windows, ones in which both the upstream PC stack and the DS PC stack have hits, and that both streams look similar. So really the only difference is where the positron starts it's journey through the detector. To make the event classification using MC information consistent with this definition, I had to carefully look at the z position where positrons started. If it starts in either the upstream or downstream PC stack -- I now call it a beam positron. Attached is a photo of today's MC event (run1event1549_0.ps).


The MCTR information for this event is:
 ------ run:   1  event:   1549  geant seeds:   577391828  0  ------
 Have   4  MonteCarlo tracks
MCTR: itrack=  1 pid= 65 istop= 0 
  V=   -0.1549   -2.6961 -300.0000 
  P=    -0.001     0.235    29.566 Q= 1 
  T=   -27.2 pmag=  29.567 cost=0.999968
MCTR: itrack=  1 pid= 65 istop= 1 
  V=    0.0448   -1.1227  -62.9930 
  P=    -3.887     1.892    25.123 
  Q= 1 T=     2.5 pmag=  25.492 cost=0.985516
MCTR: itrack=  2 pid=  2 istop= 0 
  V=    0.0448   -1.1227  -62.9930 
  P=    12.772    -9.412    44.267 
  Q= 1 T=     2.5 pmag=  47.024 cost=0.941368
MCTR: itrack=  2 pid=  2 istop= 5 
  V=    1.1187   -3.1196   82.3850 
  P=     2.361   -14.799    44.229 
  Q= 1 T=     7.7 pmag=  46.699 cost=0.947107

The MC event classification after the changes described above is:
 nMCWindows:   3
 MCWindow=  1  T0=  0.000000  nMu,nDK,nBeame,nDeltas  0  0  0  0  Min,MaxPl=  0  0  Type=  5  (Empty)
 MCWindow=  2  T0=  6.00000  nMu,nDK,nBeame,nDeltas  0  0  1  0  Min,MaxPl=  1  56  Type=  4  (Beam Positron)
 MCWindow=  3  T0=  0.000000  nMu,nDK,nBeame,nDeltas  0  0  0  0  Min,MaxPl=  0  0  Type=  5  (Empty)
 OVERALL MC EVENT TYPE=  14


Finally the event classification using just TDC information is:
 EventType:   14  (Beam Positron Trigger)
 Windows:   3
  window  1, T0= -10000., DC window= -10000.    -44., hits PC,DC=   0   0, Min,MaxZ=   99.0  -99.0, type=   5 (Empty)
  window  2, T0=      6., DC window=    -44.   1506., hits PC,DC=  14  47, Min,MaxZ=  -59.7   59.8, type=   4 (Beam Positron)
  window  3, T0=   1506., DC window=   1506.  20000., hits PC,DC=   0   2, Min,MaxZ=  -49.8   29.4, type=   5 (Empty)

-Blair

Last modified by Blair Jamieson.