Kinematics warnings with MASSIVE_PS and multiple parton interactions

[Frank Siegert]

The following warnings appear during evgen when using the "MASSIVE_PS 4 5" option while multiple parton interactions are enabled:

ZAlign::ZAlign(): p_a*p_b = 316.235 vs. 314.906, rel. diff. 0.00422113
ZAlign::ZAlign(): Q = 128.877 vs. 126.716, rel. diff. 0.0170552
Blob_List::FourMomentumConservation(): (0x4eb32e8) Four Momentum is not conserved.
   p_{in} = (8000,0,0,0) vs. p_{out} = (8000.16,-0.00445614,0.0186948,0.00348071).

They appear in about 10% of the events, leading to a New_Event.

Simple JO to reproduce the issue:

(run){
  BEAM_1 = 2212; BEAM_ENERGY_1 = 4000;
  BEAM_2 = 2212; BEAM_ENERGY_2 = 4000;

  MASSIVE_PS 4 5
}(run)

(processes){
  Process 93 93 -> 11 -12
  Order_EW 2;
  End process;
}(processes)

As soon as one switches to MI_HANDLER=None there are no issues anymore.

[Stefan Hoeche]

This should be fixed on trunk r23067. Please reopen if necessary.

[anonymous]

[http://text.com]