[Rivet] correction on ATLAS_2011_I944826 routine

[Sercan Sen]

oh right, that is the answer for this case. I run this analysis in a chain with other analyses and Kaon/Lambdas are stable.... no doubt. it seems that it works fine with a sample where we have Kaons with status 2.

Cheers
Sercan,




On Oct 26, 2012, at 2:03 PM, Frank Siegert wrote:

Hi Sercan,

So this basically means that in your sample the K_S (and Lambda?) have
been set stable and don't decay. Currently, the analysis requires them
to have a given range of transverse flight distance before decaying,
so clearly this kind of analysis can't be used with Monte-Carlo
samples that set the K_S and Lambda stable. Whether this
implementation (cutting on flight distance at the particle level) is
correct for that analysis would have to be answered by somebody more
familiar with it -- Emily?

Frank

On 26 October 2012 13:13, Sercan Sen <Sercan.Sen at cern.ch<mailto:Sercan.Sen at cern.ch>> wrote:

Hello Frank,

I didn't run this analysis before. However, I have been running some other
analyses and add this one to the chain now to see if there is any
difference.

I've just run over 150K events (INEL Z2*) both the previous version and the
new version in the trunk, but there is no event survive. Most of the events
are rejected by the flightDistance cut of Kaon/Lambda which always returns
as 1e+07. with hepmc 2.06.08 and unit is mm..

Just for my curiosity, I debug a little bit and return the pdg id of the
particle from getPerpFlightDistance function where it truly returns this
before the "if (decV)" scope. Events never go inside decV scope and
therefore the value of the flighttd which is 1e+07 is dummy in the current
code. So, all events are failed...

by the way, as expected we have more events after the correction on the MBTS
cuts and I think this will  not be only statistical effect.

* ==================

OLD VERSION

Cross-section = 7.130367e+10 pb
Rivet.Analysis.Handler: INFO  Finalising analyses
Rivet.Analysis.ATLAS_2011_I944826: INFO  Events that pass the trigger:
112103
Rivet.Analysis.ATLAS_2011_I944826: INFO  Kshort events: 0
Rivet.Analysis.ATLAS_2011_I944826: INFO  Lambda events: 0
Rivet.Analysis.Handler: INFO  Processed 150000 events

NEW VERSION

Cross-section = 7.130367e+10 pb
Rivet.Analysis.Handler: INFO  Finalising analyses
Rivet.Analysis.ATLAS_2011_I944826: INFO  Events that pass the trigger:
127174
Rivet.Analysis.ATLAS_2011_I944826: INFO  Kshort events: 0
Rivet.Analysis.ATLAS_2011_I944826: INFO  Lambda events: 0
Rivet.Analysis.ATLAS_2011_I944826: INFO  This is the modified analysis,
revision 3975
Rivet.Analysis.Handler: INFO  Processed 150000 events

Thanks,
Sercan





On Oct 25, 2012, at 3:36 PM, Frank Siegert wrote:

Hi Sercan,

Thanks again for the feedback. I have implemented the changes in changeset
3975:

http://rivet.hepforge.org/trac/changeset/3975

I don't have any possibility to test whether this does something
significantly different from before though. Sercan or Holger, since
you are probably the only two on this list who have run this analysis
before, do you have any chance to check with these changes?

Cheers,
Frank

On 24 October 2012 11:31, Sercan Sen <Sercan.Sen at cern.ch<mailto:Sercan.Sen at cern.ch>> wrote:


Hi Frank,


what about the "nstable" requirement... does that only look at

particles >100 MeV?



yes, this is what I understand from the paper -- and it's reasonable.


trigger cut is 2.09 < |\eta| < 3.84

analysis cuts: |\eta| < 2.5, 100*MeV, ....


I think the best way is to use another projection for the trigger

requirement.


Cheers,

Sercan







On Oct 23, 2012, at 3:47 PM, Frank Siegert wrote:


Hi Sercan,


Right. "nstable" part should be in |\eta| < 2.5 . So, if we extend the


rapidity acceptance in the CFS projection, then we should apply a rapidity


cut in the "nstable" part..



Thanks for the clarification.


By the way, I don't know if we need 100*MeV for ATLAS MBTS requirement (this


is applied in the current code) ? Probably, we don't need it but this should


be checked by someone from ATLAS..



Then again the same follow-up question: If the 100 MeV is not

necessary for the MBTS trigger requirement (pending confirmation by

Emily), what about the "nstable" requirement... does that only look at

particles >100 MeV?


Cheers,

Frank





-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.hepforge.org/lists-archive/rivet/attachments/20121026/3492567f/attachment.html>