Email from Yongguang:

From yl0094a@jlab.org Fri Sep 17 11:52:32 2004
Date: Fri, 17 Sep 2004 11:13:52 -0400
From: Yongguang Liang 
To: Jim Birchall 
Cc: Juliette Mammei , Roger Carlini ,
     Klaus Grimm , Mark Pitt ,
     Neven Simicevic , Greg Smith ,
     Shelley Page , Tony Forest ,
     Norman Morgan , Mike Finn ,
     David Armstrong , Dave Mack ,
     Allena Opper ,
     Richard Jones 
Subject: My simulation results for Inelastics with the '10-8-22 Boston
    collimator'

Hi Jim /et.al/,

I did a  similar simulation using 10-8-22 Boston collimator for elastic 
and inelastic (reac 3,  e+p -> e + n + pi+; reac 4, e + p -> e + p + pi+ 
+ pi-;  reac 5, e + p  -> e + p + pi0;)  processes. Attached are two 
plots I got. The first one shows the x and y positions where the elastic 
electrons (black dot) and inelastic electrons (green dot for reac 3, red 
dot for reac 5) hit the focal plane at Z=530 cm, the rectangluar area 
within the lightblue line represnts where a Cerenkov bar (200 cm long  x 
16 cm wide) may locate. No inelastic electron from reac 4 was found 
hitting the focal plane. All simulations are done with 100k events. In 
the second figure, the Q^2 distributions for these three reactions are 
ploted. The mean Q^2 for elastic process that I got is smaller than 
Jim's. I got 0.02613 and Jim's plot shows 0.03163. The possible reason 
is that I use Richard Jones's gukine.F
(see Richard's  email on 08/30/2004) which counts the energy loss of 
electron due to the pre-scattering bremsstrahlung of beam particle in
target upstream of scattering vertex. But I did not use Rcichard's 
internal correction and the new physics event generator in the simulation.


Best regards,

Yongguang        



Yongguang's attachments:

black2_green3_red5.ps
q2_for_three_reactions.ps