LHEReader doesn't work with all madgraph outputs

[awhitbeck]

I am analyzing some LHE files I got from our theory colleagues. In them there is auxiliary event-level information after each particle is listed. An example can be found here:

 7      1 +2.9536814e+04 1.71289800e+03 7.81860800e-03 8.21987300e-02
       11 -1    0    0    0    0 +0.0000000000e+00 +0.0000000000e+00 +3.9999999674e+01 4.0000000000e+01 5.1099890000e-03 0.0000e+00 -1.0000e+00
      623 -1    0    0    0    0 -0.0000000000e+00 -0.0000000000e+00 -5.9685589804e-12 1.7124600000e+03 1.7124600000e+03 0.0000e+00 1.0000e+00
       11  1    1    2    0    0 +1.9043651668e+00 -6.9159080595e-01 +8.7837770258e+00 9.0144145391e+00 5.1099890000e-03 0.0000e+00 -1.0000e+00
      623  1    1    2    0    0 +1.1962853951e-03 +3.8271048071e-01 +3.4922114418e-01 1.7124600784e+03 1.7124600000e+03 0.0000e+00 1.0000e+00
      622  2    1    2    0    0 -1.9055614522e+00 +3.0888032524e-01 +3.0867001504e+01 3.0985507087e+01 1.8982350000e+00 0.0000e+00 0.0000e+00
      -11  1    5    5    0    0 -2.8644920854e-01 -6.8086220641e-01 +5.8139920221e+00 5.8607299749e+00 5.1099890000e-03 0.0000e+00 -1.0000e+00
       11  1    5    5    0    0 -1.6191122511e+00 +9.8974253286e-01 +2.5053009602e+01 2.5124777233e+01 5.1099890000e-03 0.0000e+00 1.0000e+00
<mgrwt>
<rscale>  0 0.17128984E+04</rscale>
<asrwt>0</asrwt>
<pdfrwt beam="1">  1       11 0.10000000E+01 0.17128984E+04</pdfrwt>
<pdfrwt beam="2">  1      623 0.10000000E+01 0.17128984E+04</pdfrwt>
<totfact> 0.10000000E+01</totfact>
</mgrwt>
</event>

This breaks the LHEReader because the code expects that every line in between and (except the first?) is particle data. However, a simple fix can bypass this information and keep the code compatible with the usual LHE format we have: just change this to:

if (line == "</event>" or line=="<mgrwt>") {

This will short circuit the event block analysis and totally ignore weights. If these are useful, I guess someone will need to implement a class for interpreting and persisting this data, but for now, it's not useful to us, as far as I can tell.

[omar-moreno]

Currently, our LHE reader simply parses the events line by line. What needs to be done instead is to use a DOM parser. It should be fairly straight forward to implement, there just hasn't been any real reason to do so.

[awhitbeck]

can we implement a quick hack so that we can analyze a more general set of LHE files?

[omar-moreno]

I rather do this properly but feel free to implement a hack on a branch if you want.

…

On Fri, Jan 8, 2021 at 9:35 AM Andrew Whitbeck ***@***.***> wrote: can we implement a quick hack so that we can analyze a more general set of LHE files? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#41 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AA4JMXBEQAR3OIG7DU4MXRTSY466XANCNFSM4V2XRQ5Q> .