[Rivet] delta phi of jets with sherpa

[Ulrike Schnoor]

Hi Frank,

no, the generators don't give the same total cross section, but they
are in the same order of magnitude. Also I am using the option -x 1.0
and normalizing to cross-section/sumofweights.

The units line in the hepmc files show GEV and MM for both. Whizard
gives its cross-sections in fb, whereas Sherpa gives them in pb,
perhaps that is the reason for the large difference? Is there a way to
tell rivet the unit that the generator is using? (Sorry if this is an
ignorant question.)

Thanks,
Ulrike


2011/9/15 Frank Siegert <frank.siegert at cern.ch>:
> Hi Ulrike,
>
> this is clearly not a Rivet question, but a generator question. Have you
> checked whether both generators give the same total cross section for the
> same cuts? Also, is it possible that the units in the HepMC file are
> accidently inconsistent with what the generator claims (normally pb and
> GeV)?
>
> Frank
>
> On 15/09/11 11:10, Ulrike Schnoor wrote:
>>
>> Dear RIVET experts,
>>
>> When using RIVET to compare WHIZARD (hepmc files) to SHERPA (hepmc2g
>> files) I ran into the following problem with the azimuthal angle of
>> the jets' FourMomentum, which is happening with my own analysis as
>> well as with MC_WWJETS:
>> There are far less entries in the jets' phi or delta phi plots for
>> Sherpa than for Whizard. You can see this in the following plot made
>> with MC_WWJETS:
>> http://iktp.tu-dresden.de/~schnoor/rivet/jets_dphi_12.pdf. Has this
>> happened before, and what could I do to avoid this? I have already
>> tried to rescale the histograms, with no effect.
>> The same is happening in my private analysis that also needs the
>> azimuthal angle of jets. In addition, the MET distributions of the two
>> generators look rather different as shown in this plot:
>> http://iktp.tu-dresden.de/~schnoor/rivet/MC_VBS/missingET.pdf
>> Could this be related to the problem with the jets' phi coordinates?
>>
>> Please have a look at this and let me know if you need more information.
>> Many thanks,
>> Ulrike
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>