[Rivet] Jet fractions

[Peter Skands]

Hi Hendrik

Great! As usual on mcplots, all information is in the "more" beneath the plot 
(eg click on the experiment name), but here is the one I pointed to:

AidaPath=/REF/ALEPH_2004_S5765862/d193-x01-y01

The one at 91 GeV looks like it has the same normalization issue:
http://mcplots-dev.cern.ch/?query=plots,ee,zhad,rate-1jet#ee91
AidaPath=/REF/ALEPH_2004_S5765862/d187-x01-y01

For the other energies, it is not so clear since the experimental uncertainties 
are larger, but I presume it's the same. In all cases, it's the same ALEPH 
analysis, and it looks like the histogram numbers go from d187 to d194.

2. Another one that looks very odd is the one-jet fraction at 133 GeV  (there 
are two orders of magnitude between the MCs and the two data points that are 
'floating around' at low y):
http://mcplots-dev.cern.ch/?query=plots,ee,zhad,rate-1jet#ee133
AidaPath=/REF/ALEPH_2004_S5765862/d188-x01-y01

There, I am not sure the problem is just a normalization, but to understand what 
those two data points actually represent, if they're not just an error.


3. For the two-jet fraction, there is also a strange feature very close to y=1,
http://mcplots-dev.cern.ch/?query=plots,ee,zhad,rate-2jet#ee91
AidaPath=/REF/ALEPH_2004_S5765862/d195-x01-y01

You see that the ratio MC/data shoots up at the very rightmost end of the plot. 
When I do the analysis, I don't see that "feature" when I include neutrinos in 
the jet clustering, so I think probably the data was corrected to include those, 
while it may be that the Rivet routine is still excluding them? If so, that may 
explain most of the other disagreements I've seen so far. Let me know what you 
find, and I can give you more histogram IDs if there is more to hunt down.


4. The rapidity distributions with respect to spheriticity and thrust axes. 
There is a factor 2 between the MCs and the data (at all energies). Is it maybe 
because the data uses |y|, while the Rivet routine plots signed y ?
http://mcplots-dev.cern.ch/?query=plots,ee,zhad,yS
http://mcplots-dev.cern.ch/?query=plots,ee,zhad,yT

AidaPath=/REF/ALEPH_2004_S5765862/d36-x01-y01
   ... d51-x01-y01


Those were the things I had found so far.
Cheers,
Peter

On 6/1/12 10:21 AM, Hendrik Hoeth wrote:
> Hi Peter,
>
>> http://mcplots-dev.cern.ch/?query=plots,ee,zhad,rate-1jet#ee200
>
> since Easter is over, I'm out of egg searching practice, and my crystal
> ball is in the workshop for its periodic maintenance. Do you happen to
> have some histogram IDs for us? I know that makes life boring, but I
> like boring.
>
>> Note that we are seeing problems with all the jet fractions, not just
>> the one-jet one.
>
> Can you point us to those plots, please? With histogram IDs?
>
> Cheers,
>
>     Hendrik
>