FGT hits fired by backward tracks (Wei-Ming Zhang)

 

           1, MC tracks (eta < -1.3) are thrown backwards and FGT are found fired.
 

             Fig. 1, An events with FGT hits fired by backward tracks (UPGR16)

           2, To investigate with tracks (1.3 |eta| < 3.1) from MC events of RQMD Au-Au 10 GeV
 

            Fig. 2

 

          There are two rows in Fig. 2. Each row has three plots, the left is track multiplicity of events, the middle pt of
      tracks, and the right dE of FGT hits in KeV. The top row is plotted for backward tracks which fire FGT and for fired FGT 
      hits (backward hits). The first two of the bottom are for all backward tracks. The right of the bottom is a dE spectrum
      of FGT hits fired by FORWARD tracks (forward hits).  From Fig. 1, we see
        1, A low level of backward hits  (mult_0/mult_1 = 200 shown in the top left plot)
        2, A relatively large energy loss of backward hits which is 2-3 time larger than that of forward hits.
           This suggests backward tracks which fire FGT have very low speed and deposit more energy than forward MIPs.

         Based on the above, we believe that backward hits in FGT come from multiple scattering.
 

        Fig. 3, Split spectra of the top row of Fig. 2 for individual FGT disks: disk1 (top) disk2 (middle)
               and disk3 (bottome)
 

 

       Fig. 4, Split spectra of the top row of Fig. 2 for individual FGT disks: disk4 (top) disk5 (middle)
               and disk6 (bottome)