an event generator for inelastic electro-scattering
Genev works in 4 steps:
- Scattered
electron kinematical quantities extraction
- Extraction
of a process among all or some channels
(well tested only for ep->e'X reactions!!)
- Kinematical
quantities in the c.m. system for all stable and
unstable particles in the final state
- Decay of unstable
particles (Delta, rho, phi)
- CM --> laboratory
frame for GSIM and PAW analysis
1) V_Gamma + P ---> N + PI+
2) V_Gamma + P ---> P + PI0
3) V_Gamma + N ---> P + PI-
4) V_Gamma + N ---> N + PI0
5) V_Gamma + P ---> DELTA++
+ PI-
6) V_Gamma + P ---> DELTA+
+ PI0
7) V_Gamma + P ---> DELTA0
+ PI+
8) V_Gamma + N ---> DELTA+
+ PI-
9) V_Gamma + N ---> DELTA0
+ PI0
10) V_Gamma + N ---> DELTA-
+ PI+
11) V_Gamma + P ---> RHO0
+ P
12) V_Gamma + P ---> RHO+
+ N
13) V_Gamma + N ---> RHO-
+ P
14) V_Gamma + N ---> RHO0
+ N
15) V_Gamma + P ---> P + PI
+ PI-
16) V_Gamma + P ---> N + PI0
+ PI+
17) V_Gamma + N ---> N + PI+
+ PI-
18) V_Gamma + N ---> P + PI0
+ PI-
19) V_Gamma + P ---> OMEGA
+ P
20) V_Gamma + N ---> OMEGA
+ N
21) V_Gamma + P ---> P + PI+
+ PI- + PI0
22) V_Gamma + P ---> N + PI+
+ PI+ + PI-
23) V_Gamma + N ---> N + PI+
+ PI- + PI0
24) V_Gamma + N ---> P + PI+
+ PI- + PI-
25) V_Gamma + P ---> PHI + P
26) V_Gamma + N ---> PHI +
N
27) V_gamma + P ---> pi+ +
pi+ + pi- + pi- + p
28) V_gamma + P ---> pi+ +
pi+ + pi- + pi- + pi0 + p
29) V_gamma + P ---> pi+ +
pi+ + pi+ + pi- + pi- + n
Decay of unstable particles
- Inelastic cross-section
- Q2 dependence
- fixed w and
q bin (free Q2 and W)
- fixed w and
q bin and Q2 (free W)
- fixed w and
q bin and W (free Q2)
- fixed W and
Q2 bin (free w and q)
- Real photon
cross section s(W)
- tabulated
cross sections (10 MeV W steps)
- phenomenological
fit for 1 pion
- phenomenological
calculation + data fit for 2 pions
- w and multipions
production obtained interpolating available data
Total cross
section
2 pions total cross section
- tabulated
angular distribution (9 degrees steps)
- for 1- 2 pions,
w and F channels experimental data are used
- for multipions
channels phase sspace extraction (GENBOD)
phi distributions: all
channels have uniform distr. but single pion
theta, phi of
pion in rho rest frame
All other channels
have an uniform distribution for decaying particles
genev_hp.lund
! lund file name
12.5
! teta_min electron (degrees)
55.
! teta_max electron (degrees)
0
! flag to fix Q2 (1=read Qmin,Qmax; 0=ignore them)
0.6
! Q2min WARNING!! If Q2 and W flags are BOTH=1 extraction
4.0
! Q2max is made in Q2,W bin; elsewere in Omega,theta bin
1
! flag to fix W (1=read Wmin,Wmax; 0=ignore them)
0
!flag to fix phi of e- (1=read phi_min,phi_max;0=ignore them)
16
! number of activated channels channels
1,2,5,6,7,11,12,15,16,19,21,22,25,27,28,29
! channels ID (in one line, ID
! separeted by a coma e.g 1,3,4..)
0
!Flag Rho ds/dt (0=ds/dt true; 1=uniform 2=flat 3=fixed angle)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
1) V_Gamma + P ---> N + PI+
2) V_Gamma + P ---> P + PI0
3) V_Gamma + N ---> P + PI-
4) V_Gamma + N ---> N + PI0
5) V_Gamma + P ---> DELTA++ + PI-
6) V_Gamma + P ---> DELTA+ + PI0
7) V_Gamma + P ---> DELTA0 + PI+
8) V_Gamma + N ---> DELTA+ + PI-
9) V_Gamma + N ---> DELTA0 + PI0
10) V_Gamma + N ---> DELTA- + PI+
11) V_Gamma + P ---> RHO0 + P
12) V_Gamma + P ---> RHO+ + N
13) V_Gamma + N ---> RHO- + P
14) V_Gamma + N ---> RHO0 + N
15) V_Gamma + P ---> P + PI + PI-
16) V_Gamma + P ---> N + PI0 + PI+
17) V_Gamma + N ---> N + PI+ + PI-
18) V_Gamma + N ---> P + PI0 + PI-
19) V_Gamma + P ---> OMEGA + P
20) V_Gamma + N ---> OMEGA + N
21) V_Gamma + P ---> P + PI+ + PI-
+ PI0
22) V_Gamma + P ---> N + PI+ + PI+
+ PI-
23) V_Gamma + N ---> N + PI+ + PI-
+ PI0
24) V_Gamma + N ---> P + PI+ + PI-
+ PI-
25) V_Gamma + P ---> PHI + P
26) V_Gamma + N ---> PHI + N
27) V_gamma + p ---> pi+ + pi+ +
pi- + pi- + p
28) V_gamma + p ---> pi+ + pi+ +
pi- + pi- + pi0 + p
29) V_gamma + p ---> pi+ + pi+ +
pi+ + pi- + pi- + n
Simulation/data comparison
(left)SIMULATION w, q fixed and Q2>0.5
(right) Run 9158 (4GeV low field)
SIMULATION w,
q fixed and 1<W>2.8