Cross section unaffected with ISR in THDM set in the unitarity gauge

Dear Tabira,
thanks for providing the UFO model. When I run your SINDARIN with and without ISR, I get different results, without ISR:
 Beam structure: [any particles]
| Beam data (collision):
| e- (mass = 5.1100000E-04 GeV)
| e+ (mass = 5.1100000E-04 GeV)
| sqrts = 2.500000000000E+02 GeV
| Phase space: generating configuration ...
| Phase space: ... success.
| Phase space: writing configuration file 'eehvv.i1.phs'
| ------------------------------------------------------------------------
| Process [scattering]: 'eehvv'
| Library name = 'default_lib'
| Process index = 1
| Process components:
| 1: 'eehvv_i1': e-, e+ => ve:vm:vt, ve~:vm~:vt~, h1 [omega]
| ------------------------------------------------------------------------
| Phase space: 25 channels, 5 dimensions
| Phase space: found 25 channels, collected in 12 groves.
| Phase space: Using 37 equivalences between channels.
| Phase space: wood
Warning: No cuts have been defined.
| Starting integration for process 'eehvv'
| Integrate: iterations not specified, using default
| Integrate: iterations = 5:5000:"gw", 3:10000:""
| Integrator: 12 chains, 25 channels, 5 dimensions
| Integrator: Using VAMP channel equivalences
| Integrator: 5000 initial calls, 20 bins, stratified = T
| Integrator: VAMP
|=============================================================================|
| It Calls Integral[fb] Error[fb] Err[%] Acc Eff[%] Chi2 N[It] |
|=============================================================================|
   1 4975 2.3917745E+02 5.46E+00 2.28 1.61* 12.89
   2 4963 2.3287032E+02 2.44E+00 1.05 0.74* 30.82
   3 4947 2.3686971E+02 1.67E+00 0.71 0.50* 42.26
   4 4934 2.3612791E+02 1.38E+00 0.58 0.41* 50.33
   5 4920 2.3576314E+02 1.30E+00 0.55 0.39* 49.36
|-----------------------------------------------------------------------------|
   5 24739 2.3589287E+02 7.72E-01 0.33 0.51 49.36 0.57 5
|-----------------------------------------------------------------------------|
   6 9990 2.3537677E+02 8.93E-01 0.38 0.38* 46.73
   7 9990 2.3439949E+02 8.98E-01 0.38 0.38 43.46
   8 9990 2.3362040E+02 8.97E-01 0.38 0.38 42.56
|-----------------------------------------------------------------------------|
   8 29970 2.3446851E+02 5.17E-01 0.22 0.38 42.56 0.97 3
|=============================================================================|

and with ISR:
| Beam structure: e-, e+ => isr
| Beam data (collision):
| e- (mass = 5.1100000E-04 GeV)
| e+ (mass = 5.1100000E-04 GeV)
| sqrts = 2.500000000000E+02 GeV
| Phase space: discarding old configuration (configuration parameters changed)
| Phase space: generating configuration ...
| Phase space: ... success.
| Phase space: writing configuration file 'eehvv.i1.phs'
| ------------------------------------------------------------------------
| Process [scattering]: 'eehvv'
| Library name = 'default_lib'
| Process index = 1
| Process components:
| 1: 'eehvv_i1': e-, e+ => ve:vm:vt, ve~:vm~:vt~, h1 [omega]
| ------------------------------------------------------------------------
| Phase space: 25 channels, 5 dimensions
| Phase space: found 25 channels, collected in 12 groves.
| Phase space: Using 37 equivalences between channels.
| Phase space: wood
| Beam structure: isr, none => none, isr
| Beam structure: 1 channels, 2 dimensions
Warning: No cuts have been defined.
| Starting integration for process 'eehvv'
| Integrate: iterations not specified, using default
| Integrate: iterations = 5:5000:"gw", 3:10000:""
| Integrator: 12 chains, 25 channels, 7 dimensions
| Integrator: Using VAMP channel equivalences
| Integrator: 5000 initial calls, 20 bins, stratified = T
| Integrator: VAMP
|=============================================================================|
| It Calls Integral[fb] Error[fb] Err[%] Acc Eff[%] Chi2 N[It] |
|=============================================================================|
| VAMP: parameter mismatch, discarding grid file 'eehvv.m1.vg'
   1 4975 1.9370501E+02 5.48E+00 2.83 1.99* 8.99
   2 4960 1.9216560E+02 2.26E+00 1.18 0.83* 26.17
   3 4945 1.8997635E+02 1.70E+00 0.89 0.63* 29.70
   4 4929 1.9210900E+02 1.56E+00 0.81 0.57* 29.80
   5 4916 1.9354021E+02 1.44E+00 0.75 0.52* 32.42
|-----------------------------------------------------------------------------|
   5 24725 1.9211536E+02 8.26E-01 0.43 0.68 32.42 0.66 5
|-----------------------------------------------------------------------------|
   6 9988 1.9109346E+02 1.04E+00 0.54 0.54 27.09
   7 9988 1.9035335E+02 1.01E+00 0.53 0.53* 24.64
   8 9988 1.9040257E+02 1.00E+00 0.53 0.53* 24.25
|-----------------------------------------------------------------------------|
   8 29964 1.9060757E+02 5.87E-01 0.31 0.53 24.25 0.16 3
|=============================================================================|

That's strange. This is what I get w/o ISR

 Phase space: 25 channels, 5 dimensions
| Phase space: found 25 channels, collected in 12 groves.
| Phase space: Using 37 equivalences between channels.
| Phase space: wood
Warning: No cuts have been defined.
| Starting integration for process 'eehvv'
| Integrate: iterations not specified, using default
| Integrate: iterations = 5:5000:"gw", 3:10000:""
| Integrator: 12 chains, 25 channels, 5 dimensions
| Integrator: Using VAMP channel equivalences
| Integrator: 5000 initial calls, 20 bins, stratified = T
| Integrator: VAMP
|=============================================================================|
| It Calls Integral[fb] Error[fb] Err[%] Acc Eff[%] Chi2 N[It] |
|=============================================================================|
| VAMP: using grids and results from file 'eehvv.m1.vg'
   1 4975 2.3225389E+02 5.21E+00 2.24 1.58* 11.66
   2 4959 2.3667549E+02 2.56E+00 1.08 0.76* 31.01
   3 4946 2.3414591E+02 1.74E+00 0.74 0.52* 38.31
   4 4935 2.3409974E+02 1.39E+00 0.59 0.42* 46.70
   5 4919 2.3479107E+02 1.29E+00 0.55 0.39* 49.49
|-----------------------------------------------------------------------------|
   5 24734 2.3456001E+02 7.81E-01 0.33 0.52 49.49 0.27 5
|-----------------------------------------------------------------------------|
| VAMP: using grids and results from file 'eehvv.m1.vg'
   6 9988 2.3518122E+02 9.00E-01 0.38 0.38* 44.83
   7 9988 2.3718242E+02 9.05E-01 0.38 0.38* 42.28
   8 9988 2.3469729E+02 9.01E-01 0.38 0.38 40.94
|-----------------------------------------------------------------------------|
   8 29964 2.3568246E+02 5.21E-01 0.22 0.38 40.94 2.13 3
|=============================================================================|

with ISR:

| Phase space: 25 channels, 5 dimensions
| Phase space: found 25 channels, collected in 12 groves.
| Phase space: Using 37 equivalences between channels.
| Phase space: wood
Warning: No cuts have been defined.
| Starting integration for process 'eehvv'
| Integrate: iterations not specified, using default
| Integrate: iterations = 5:5000:"gw", 3:10000:""
| Integrator: 12 chains, 25 channels, 5 dimensions
| Integrator: Using VAMP channel equivalences
| Integrator: 5000 initial calls, 20 bins, stratified = T
| Integrator: VAMP
|=============================================================================|
| It Calls Integral[fb] Error[fb] Err[%] Acc Eff[%] Chi2 N[It] |
|=============================================================================|
| VAMP: using grids and results from file 'eehvv.m1.vg'
   1 4975 2.3225389E+02 5.21E+00 2.24 1.58* 11.66
   2 4959 2.3667549E+02 2.56E+00 1.08 0.76* 31.01
   3 4946 2.3414591E+02 1.74E+00 0.74 0.52* 38.31
   4 4935 2.3409974E+02 1.39E+00 0.59 0.42* 46.70
   5 4919 2.3479107E+02 1.29E+00 0.55 0.39* 49.49
|-----------------------------------------------------------------------------|
   5 24734 2.3456001E+02 7.81E-01 0.33 0.52 49.49 0.27 5
|-----------------------------------------------------------------------------|
| VAMP: using grids and results from file 'eehvv.m1.vg'
   6 9988 2.3518122E+02 9.00E-01 0.38 0.38* 44.83
   7 9988 2.3718242E+02 9.05E-01 0.38 0.38* 42.28
   8 9988 2.3469729E+02 9.01E-01 0.38 0.38 40.94
|-----------------------------------------------------------------------------|
   8 29964 2.3568246E+02 5.21E-01 0.22 0.38 40.94 2.13 3
|=============================================================================|

Since you got different results, the ufo seems to be fine. Maybe something is going wrong with my machine.

I think your SINDARIN file is wrong. Your output above shows 5 (integration) dimensions for a 2->3 process without ISR. Each ISR structure function adds one integration dimension, so that you should have 7 (integration) dimensions, as you can see in my output above. Could it be that your beams statement appears after the integrate statement in your SINDARIN? Then it would not act on that integration.

It appears before. My sindarin file contains exactly the same code shown in the question. It's just that my whizard isn't acknowledging that isr has been switched on.

When I tried to do the same for SM which is already built into whizard, it was working. The isr functionality gets ignored when I implement UFO.

That is really strange. Just to confirm, this was on your laptop, an Apple M1 processor, right? Could you cross check on a Linux machine, please? What happens if you run the SINDARIN with the ISR statement in the beams in a completely empty directory?
I.e. in a directory where no Whizard process has been run before. In case that also doesn't work could you send us (via email as before) the whizard.log of that run and also the THDMUG.ufo.mdl file that Whizard produced?

Yes, it's the M1 processor. And sure, I shall be giving you an update later today!

Hello,

So I ran it on my colleague's linux laptop who had whizard already installed, and it worked, I got the same results as yours. But when I ran it in an empty directory on my laptop, there was no change. I am emailing the files.

also, about the values, they are not falling within an acceptable range and should be much less. When I ran the same code with the ufo generated from SARAH (which was in the rxi gauge), I got ~47 fb (without ISR) which is alright (for SM, it is ~55fb), but that ufo isn't running with ISR on linux. Would you have any idea as to why these values are turning out to be so large, and how I could possibly adjust the code to get a value within the acceptable range? Thank you.

The files you send us look normal, except that they are already from a second run (WHIZARD is reusing existing phase space files and integration grids.) Can you send us also the whizard.log from the run in an empty directory, please? Unfortunately, at the moment we don't have access to a system with an Apple M1 chip, so this is hard for us to debug. Are you around at DESY campus? otherwise we could make a session with screen share to directly discuss this.
Regarding the cross sections, are you sure you are comparing identical processes in the different models? If you sum over the neutrino flavors, you also get contributions from pure Higgsstrahlung (as you get for the process with electron neutrinos). It could also be that there is still a mistake in your UFO model.

I am comparing identical processes, but yeah, the ufo could be faulty too. And I am coming to desy tomorrow, so if you are able to make time, we can sit down with the laptop and figure out what's really going on.

My problem has been solved. Thank you.

Just for completeness: the ignored QED ISR option in the SINDARIN seems to have been caused by a remnant from a previous run
in the working directory. The differences in the cross sections between the two different UFO files (from FeynRules in unitarity gauge and from SARAH in R_xi gauge) come from the fact that in the first the (light) Yukawa couplings are 1 (or order 1) per default, but zero in the SARAH UFO model. The default Higgs masses (h1, h2, A, H+, H-) are of the order of 100 GeV, and not all were reset in the input file. Hence, there were contributions from (resonant) Yukawa (s-channel) exchange, leading to cross sections too large by two orders of magnitude for the Unitarity Gauge model.