dparameter and ktdurham
Hi,
I generated ZZ+0,1,2,3jets events with CKKW merging and also ZZ+0j events. But I found that at matrix element level, the cross section I got from ZZ+0j (0.5727 pb) is actually larger than ZZ+0,1,2,3jets (0.548 pb). Since this is at matrix element level, I'd expect the cross section for the inclusive sample (ZZ+0,1,2,3jets) should be larger than the ZZ+0j sample.
The only difference I found in my setting is that, when I run the inclusive sample, I have
'ickkw':"0",
'ktdurham' : 30,
'dparameter' : 0.4,
while I remove those when I run the ZZ+0j sample.
Then I tried to run ZZ+0j with those settings, and I got a smaller cross section at matrix element (0.338 pb).
My understanding is that those settings are only used in Pythia for showering, and at matrix element calculation, they should not have any effect. Do you have any suggestion?
You can find my lhe files below if you want to see more details:
ZZ+0,1,2,3jets: https:/
ZZ+0j without ktdurham and dparameter: https:/
ZZ+0j with ktdurham and dparameter: https:/
Thanks,
Lailin
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- Stefan Prestel Edit question
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