Muons from Z->mumu are not set to status = 1 (ie stable) in HepEvt format

[ghesketh@fnal.gov]

I'm generating p pbar -> mu mu (+jets). I've just upgrades to SHERPA v1.1.2, and using the HepEvt interface it looks like the muons are not set to status = 1 (ie stable). This was not a problem with v1.1.1. Below is one event dump - the muons are particles 17 and 18: they do not have any daughters, but have status = 2.

1 126

1 2 2212 0 0 2 5

0 0 980 980 0.938272 0 0 0 0

2 2 2 1 0 6 6

-1.42182 1.23367 132.496 132.509 0.005 0 0 0 0

3 2 2203 1 0 19 19

-1.19524 -0.465559 393.394 393.397 0.77133 0 0 0 0

4 2 1 1 0 19 19

2.49496 -0.434082 369.888 369.897 0.01 0 0 0 0

5 2 -2 1 0 19 19

0.1221 -0.334026 84.2051 84.2058 0.005 0 0 0 0

6 2 2 2 0 13 13

-1.42182 1.23367 132.496 132.509 0.005 0 0 0 0

7 2 -2212 0 0 8 11

0 0 -980 980 0.938272 0 0 0 0

8 2 -2 7 0 12 12

0.29061 -0.288696 -15.4382 15.4437 0.005 0 0 0 0

9 2 -2103 7 0 19 19

0.349271 0.625612 -546.99 546.991 0.77133 0 0 0 0

10 2 -2 7 0 19 19

-0.488963 -0.595912 -321.061 321.062 0.005 0 0 0 0

11 2 2 7 0 19 19

-0.150919 0.258995 -96.4941 96.4946 0.005 0 0 0 0

12 2 -2 8 0 14 14

0.29061 -0.288696 -15.4382 15.4437 0.005 0 0 0 0

13 2 2 6 6 15 16

-1.42182 1.23367 132.496 132.509 2.31616e-06 0 0 0 0

14 2 -2 12 12 15 16

0.29061 -0.288696 -15.4382 15.4437 3.00273e-07 0 0 0 0

15 2 13 13 14 17 17

38.5137 -22.2323 60.9301 75.4325 0 0 0 0 0

16 2 -13 13 14 18 18

-39.6449 23.1773 56.1273 72.5202 8.16442e-07 0 0 0 0

17 2 13 15 15 0 0

38.5136 -22.2323 60.9301 75.4325 0.105 0 0 0 0

18 2 -13 16 16 0 0

-39.6448 23.1773 56.1273 72.5202 0.105 0 0 0 0

--snip--

[Frank Siegert]

Thanks for the report, we are working on a solution for the problem.

[ghesketh@fnal.gov]

I've just tried v1.1.3, and this bug no longer seems to exist.

[Stefan Hoeche]

Milestone old deleted