build-event-from-scratch

Documentation

Overview

In this example we will place the following event into HepMC "by hand"

   name status pdg_id  parent Px       Py    Pz       Energy      Mass
1  !p+!    3   2212    0,0    0.000    0.000 7000.000 7000.000    0.938
2  !p+!    3   2212    0,0    0.000    0.000-7000.000 7000.000    0.938

=========================================================================

3  !d!     3      1    1,1    0.750   -1.569   32.191   32.238    0.000
4  !u~!    3     -2    2,2   -3.047  -19.000  -54.629   57.920    0.000
5  !W-!    3    -24    1,2    1.517   -20.68  -20.605   85.925   80.799
6  !gamma! 1     22    1,2   -3.813    0.113   -1.833    4.233    0.000
7  !d!     1      1    5,5   -2.445   28.816    6.082   29.552    0.010
8  !u~!    1     -2    5,5    3.962  -49.498  -26.687   56.373    0.006

now we build the graph, which will look like

#                       p7                         #
# p1                   /                           #
#   \v1__p3      p5---v4                           #
#         \_v3_/       \                           #
#         /    \        p8                         #
#    v2__p4     \                                  #
#   /            p6                                #
# p2                                               #
#                                                  #