unstable PS point detected
Dear MG/aMC@NLO experts,
I was testing generation of
p p > mu+ mu- [QCD] @0 ; p p > mu+ mu- j [QCD] @1 ; p p > mu+ mu- j j [QCD] @2
for the UNLOPS matching/merging. Run goes fine but it end with a message
Number of loop ME evaluations (by MadLoop): 3134633
Stability unknown: 0
Stable PS point: 3133011
Unstable PS point (and rescued): 1618
Unstable PS point (and not rescued): 4
Only double precision used: 3133011
Quadruple precision used: 1622
Initialization phase-space points: 1176
Reduction methods used:
> CutTools (double precision) 3125616
> IREGI 7395
> CutTools (quadruple precision) 1618
> Not identified (CTModeRun != -1) 4
Total number of unstable PS point detected: 4 (0.00%)
Maximum fraction of UPS points in channel mu+mu-_
The fraction of unstable PS point is negligible, but still I though it might be worthwhile to report it. Is this expected or is this a bug?
cheers,
Wojciech
Question information
- Language:
- English Edit question
- Status:
- Open
- Assignee:
- Valentin Hirschi Edit question
- Last query:
- 2015-01-03
- Last reply:
- 2015-01-03
Hi,
Yes this is completely expected, all those rescued means that the problem were solved by using a slower method of computation.
(can be 100 times slower to compute than the normal method).
Valentin might be interested by the fact that you still have 4 point that are not rescued and set to zero.
Cheers,
Olivier
Dear Olivier,
Thanks a lot for looking into this and sorry for not being very precise. What I was worried about are precisely those 4 points you mentioned. The ones that weren't "fixed" by rescue/fallback system.
cheers,
Wojciech
Can you help with this problem?
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