Hadronization crashes after broken shower

[Frank Siegert]

I see a crash from Ahadic's Gluon_Decayer for which the shower seems to be the culprit. I am attaching a logfile where the last two events have debug output, and the crash happens in the last event. I guess it comes from the fact that the shower produces the following blob (note the colour flow):

    Blob [36]( 2, Shower            , 6 -> 7 @ (0,0,0,0)
    Incoming particles :
    [H] 2 G                     3 (   1 ->    2) [( 4.0499e+01, 3.7906e+01, 1.4231e+01,-8.7554e-01), p^2= 4.5475e-13, m= 0.0000e+00] (501,502)
    [H] 2 G                     4 (   1 ->    2) [( 3.1213e+01,-2.8870e+01,-9.7946e+00, 6.6925e+00), p^2=-3.4106e-13, m= 0.0000e+00] (502,503)
    [H] 2 s                     5 (   1 ->    2) [( 1.4390e+01,-1.3425e+01,-3.8079e+00,-3.5103e+00), p^2=-1.9895e-13, m= 0.0000e+00] (503,  0)
    [H] 2 sb                    6 (   1 ->    2) [( 4.9177e+00, 4.3897e+00,-6.2872e-01,-2.1258e+00), p^2= 0.0000e+00, m= 0.0000e+00] (  0,501)
    [I] 2 e-                    7 (   3 ->    2) [( 4.5600e+01, 0.0000e+00, 0.0000e+00, 4.5600e+01), p^2= 0.0000e+00, m= 0.0000e+00] (  0,  0)
    [I] 2 e+                    8 (   4 ->    2) [( 4.5419e+01, 0.0000e+00, 0.0000e+00,-4.5419e+01), p^2= 1.3642e-12, m= 0.0000e+00] (  0,  0)
    Outgoing particles :
    [G] 2 e-                    1 (   2 ->    1) [( 4.5600e+01, 0.0000e+00, 0.0000e+00, 4.5600e+01), p^2= 0.0000e+00, m= 0.0000e+00] (  0,  0)
    [G] 2 e+                    2 (   2 ->    1) [( 4.5419e+01, 0.0000e+00, 0.0000e+00,-4.5419e+01), p^2= 1.3642e-12, m= 0.0000e+00] (  0,  0)
    [F] 1 G                     9 (   2 ->     ) [( 3.9134e+01, 3.6628e+01, 1.3751e+01,-8.4602e-01), p^2= 6.8212e-13, m= 0.0000e+00] (601,602)
    [F] 1 G                    10 (   2 ->     ) [( 2.9677e+01,-2.8162e+01,-8.4902e+00, 3.9411e+00), p^2=-7.9581e-13, m= 0.0000e+00] (602,603)
    [F] 1 G                    11 (   2 ->     ) [( 2.9006e+00, 5.6978e-01,-8.2467e-01, 2.7219e+00), p^2=-1.4211e-14, m= 0.0000e+00] (602,602)
    [F] 1 s                    12 (   2 ->     ) [( 1.4390e+01,-1.3425e+01,-3.8079e+00,-3.5103e+00), p^2=-1.9895e-13, m= 0.0000e+00] (603,  0)
    [F] 1 sb                   13 (   2 ->     ) [( 4.9177e+00, 4.3897e+00,-6.2872e-01,-2.1258e+00), p^2= 0.0000e+00, m= 0.0000e+00] (  0,601)

[Stefan Hoeche]

Frank, can you check whether the problem persists with current trunk? According to the log file this might have been a shower setup issue related to ticket #145.

[Frank Siegert]

I already know that this problem still appears in r17188, which is the fix for #145. Did anything happen afterwards, of which you suspect it could have fixed this?

[Stefan Hoeche]

As the problem is hard to (re)produce, I have (for now) added a safety check with r17207 that should skip to the next event upon singlet gluon detection in the remnant handler.

[Stefan Hoeche]

Fixed with r17329.