Sibyll pi0 decay produces a "NaN" pair of pi+/pi- ?

[corsika:info    ] custom pattern: StackInspector: i=     1, id=       p+        E=   9.988954e+02 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     2, id=      pbar-      E=   1.159157e+02 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     3, id=       n0        E=   1.622720e+02 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     4, id=       pi+       E=   3.098412e+02 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     5, id=       pi0       E=   1.699065e+02 GeV,  pos= (4.6592e-18 5.62096e-17 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector:  time= 19:26:07, running= 8.222932786 seconds ( 6%), nStep= 3, stackSize= 16, Estack= 3756.0056452775098 GeV, ETA=
[corsika:debug   ] custom pattern: Interaction: LambdaInt: 
 input energy: 169.90654508346168 GeV  beam can interact: false  beam pid: pi0
[corsika:debug   ] custom pattern: total_lambda=inf g/cm2, , next_interact=inf g/cm2
[corsika:debug   ] custom pattern: Sibyll::Decay: code: pi0 
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: t0: 8.51632e-17 s 
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: energy: 169.90654508346168 GeV 
[corsika:debug   ] custom pattern: Sibyll::Decay: momentum: (0.217241 0.240888 -169.906) [] GeV 
[corsika:debug   ] custom pattern: Sibyll::Decay: momentum: shell mass-kin. inv. mass 0.0115504944513024 0.018219600399999997
[corsika:debug   ] custom pattern: Sibyll::Decay: sib mass: 0.5905920267105103
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: gamma:  1258.753482615659
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: tau 1.0719953752836802e-13 s: 
[corsika:debug   ] custom pattern: total_lifetime=1.0719953752836802e-13 s, next_decay=3.43547425142168e-14 s
[corsika:debug   ] custom pattern: Tracking pid: pi0 , E = 169.90654508346168 GeV
[corsika:debug   ] custom pattern: Tracking pos: (4.6592e-18 5.62096e-17 112144) m
[corsika:debug   ] custom pattern: Tracking   E: 169.90654508346168 GeV
[corsika:debug   ] custom pattern: Tracking   p: (0.217241 0.240888 -169.906) [] GeV
[corsika:debug   ] custom pattern: Tracking   v: (383313 425036 -2.99792e+08) m/s 
[corsika:debug   ] custom pattern: volumeNode=0x559795fbede0, numericallyInside=true 
[corsika:debug   ] custom pattern: intersection times with currentLogicalVolumeNode: -0.00012627394832155414 s and 0.0008744175181178356 s
[corsika:debug   ] custom pattern: transport particle by : 1.0299290641864431e-05 m Medium transition after: 107148.46342535352 m Decay after: 1.0299290641864431e-05 m Interaction after: inf m Continuous limit: inf m 
[corsika:debug   ] custom pattern: ParticleCut: checking pi0, E= 169.90654508346168 GeV, EcutTot=242.5909928081996 GeV
[corsika:debug   ] custom pattern: discrete process before geometric limit ? yes
[corsika:debug   ] custom pattern: decay
[corsika:debug   ] custom pattern: Sibyll::Decay: code: pi0 
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: t0: 8.51632e-17 s 
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: energy: 169.90654508346168 GeV 
[corsika:debug   ] custom pattern: Sibyll::Decay: momentum: (0.217241 0.240888 -169.906) [] GeV 
[corsika:debug   ] custom pattern: Sibyll::Decay: momentum: shell mass-kin. inv. mass 0.0115504944513024 0.018219600399999997
[corsika:debug   ] custom pattern: Sibyll::Decay: sib mass: 0.5905920267105103
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: gamma:  1258.753482615659
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: tau 1.0719953752836802e-13 s: 
[corsika:debug   ] custom pattern: Sibyll::Decay: code: pi0 
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: t0: 8.51632e-17 s 
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: energy: 169.90654508346168 GeV 
[corsika:debug   ] custom pattern: Sibyll::Decay: momentum: (0.217241 0.240888 -169.906) [] GeV 
[corsika:debug   ] custom pattern: Sibyll::Decay: momentum: shell mass-kin. inv. mass 0.0115504944513024 0.018219600399999997
[corsika:debug   ] custom pattern: Sibyll::Decay: sib mass: 0.5905920267105103
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: gamma:  1258.753482615659
[corsika:debug   ] custom pattern: Sibyll::Decay: MinStep: tau 1.0719953752836802e-13 s: 
[corsika:debug   ] custom pattern: Sibyll::Decay: setting pi0 unstable. 
[corsika:debug   ] custom pattern: Decay: Sibyll decay configuration: pi0 is unstable
[corsika:debug   ] custom pattern: Decay: calling Sibyll decay routine..
[corsika:debug   ] custom pattern: Sibyll::Decay: setting pi0 stable. 
[corsika:debug   ] custom pattern: ParticleCut: checking pi+, E= -nan GeV, EcutTot=242.5909928081996 GeV
[corsika:debug   ] custom pattern: ParticleCut: checking pi-, E= nan GeV, EcutTot=242.5909928081996 GeV
[corsika:info    ] custom pattern: StackInspector: i=     0, id=     nucleus     E=   1.999175e+03 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: nuc_ref= 1
[corsika:info    ] custom pattern: StackInspector: i=     1, id=       p+        E=   9.988954e+02 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     2, id=      pbar-      E=   1.159157e+02 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     3, id=       n0        E=   1.622720e+02 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     4, id=       pi+       E=   3.098412e+02 GeV,  pos= (0 0 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     5, id=       pi+       E=-nan            GeV,  pos= (1.31686e-08 1.4602e-08 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector: i=     6, id=       pi-       E=nan             GeV,  pos= (1.31686e-08 1.4602e-08 112144) m node = 0x559795fbede0
[corsika:info    ] custom pattern: StackInspector:  time= 19:26:07, running= 8.223310104 seconds ( -2147483648%), nStep= 4, stackSize= 18, Estack= nan GeV, ETA=
[corsika:debug   ] custom pattern: Interaction: LambdaInt: 

changed milestone to %ICRC-2021

added Bug Physics labels

@riehn Felix, do you have time to look at this? First question is, if you can reproduce that:

• take current master HEAD, 1st March 2021
• run "cascade_example"
• it fails with the above symptom
• there are 5 particles on the stack. The pi0 decays, in sibyll into a pair of broken pi+/pi-
• subsequent tracking crashes

Yes I will look into it.

@rulrich I do not seem to be able to reproduce the failure. I used 5e3a9b43. Did you have the seed fixed?

Something really strange seems to be going on.
Sibyll::Decay: sib mass: 0.5905920267105103 thats

$m^2$

for

$\rho^0$

not

$\pi^0$

.
the mass is calculated by asking sibyll get_sibyll_mass2(sib_id) so somewhere the id's get confused

I check. Maybe it is just a messed-up build environment on my side.... this is too strange otherwise.

Sorry for bothering you. It was fixed by a fresh build.

closed