[Rivet] Question on searches in rivet

[Lucia Masetti]

Hi Andy,
thank you very much for answering my question from your holiday. That's 
exactly what I wanted to know! Now I understand the idea and it means 
that for resonance searches in a much less "special" phase space on top 
of a huge background it wouldn't work so easily.

Cheers,
Lucia
> I'm on holiday at the moment so can't answer properly, but the short
> answer is that a lot of BSM analyses are relatively insensitive to
> detector effects: the cuts on HT or missing ET are sufficiently high
> that soft contributions to it are irrelevant, for example. Some of the
> truth-level BSM studies in Rivet were checked against the likelihood
> contours given by ATLAS and more or less reproduced the same result.
>
> So they can be usefully used for phenomenology without getting into
> detector fast simulation, which may not be doing such a great job in
> practice and should really be checked in detail for each case although
> there are hundreds of pheno papers which run it blindly...
>
> Andy
>
>
> On 23/09/14 13:09, Lucia Masetti wrote:
>> Dear Andy, all,
>> thank you very much for the information!
>>
>> My interest is in the analyses that include a comparison with reference
>> data. While the search results in general include a limit on the signal
>> cross-section (or number of events for the given luminosity), which can
>> be compared with the truth level analysis, I don't understand how
>> histograms can be compared. For example in ATLAS_2011_S9212183 there are
>> 4 histograms in the paper that look to me like reconstruction level and
>> they are given for comparison in the reference data. I wonder how it is
>> possible to compare non-unfolded data with histograms produced in a
>> Rivet analysis. Can you please help me understanding the idea behind
>> this kind of procedure?
>>
>> Cheers,
>> Lucia
>>> On 03/09/14 13:57, Lucia Masetti wrote:
>>>> Hi Andy,
>>>> in the ttbar resonances team we are discussing what information to put
>>>> on HEPData, with the aim (hope) that our limits can be recast with new
>>>> models whenever a theorist wants to test their new ideas.
>>>> At the Boost workshop you mentioned that in Rivet there are not only
>>>> unfolded measurements, but also searches. How is the comparison btw MC
>>>> and data within Rivet intended to be done in those cases? Does the code
>>>> provide only event selection and reconstruction routines or also some
>>>> tools to compute the limits? Can you maybe point me to some examples I
>>>> could take as example?
>>> Hi Lucia,
>>>
>>> Apologies for the delayed reply. I have copied this to the Rivet
>>> developer list where you'd have got a faster response!
>>>
>>> Rivet doesn't contain any likelihood machinery -- this could conceivably
>>> be added if a good enough interface proposal (i.e. sufficiently general
>>> without being unusable) could be designed. On BSM fitting projects that
>>> I'm involved with, we typically need to know the background rate and
>>> uncertainty for each signal region, the integrated luminosity of the
>>> sample, ideally some information about correlation between regions, etc.
>>> ... and I haven't yet seen a uniform interface for passing enough info.
>>>
>>> So I think what Rivet currently does -- i.e. just report the numbers of
>>> events passing cuts, or better: the signal cross-section and acceptances
>>> -- is probably ok for now. As our histogramming tools develop, we can do
>>> that in a more structured way than just print-outs into the log: there
>>> are now Counter objects which should be ideal for that purpose, and
>>> automatically writing cross-section info into the output is planned.
>>>
>>> Here is a very quickly obtained list of search implementations in Rivet
>>> (maybe not exhaustive, and I know that e.g. the ATOM fitting
>>> collaboration have implemented a bunch more for their own use):
>>>
>>> andy at duality:~$ rivet --list-analyses | grep -i search
>>> ATLAS_2011_CONF_2011_090    Single lepton search for supersymmetry
>>> ATLAS_2011_CONF_2011_098    [UNVALIDATED] B-jets search for
>>> supersymmetry with 0-leptons
>>> ATLAS_2011_S8983313         0-lepton squark and gluino search
>>> ATLAS_2011_S9019561         Two lepton supersymmetry search
>>> ATLAS_2011_S9041966         [UNVALIDATED] 1-lepton and 2-lepton search
>>> for first or second generation leptoquarks
>>> ATLAS_2011_S9108483         [UNVALIDATED] Long-lived heavy charged
>>> particle search
>>> ATLAS_2011_S9212183         0-lepton squark and gluino search
>>> ATLAS_2011_S9212353         [UNVALIDATED] Single lepton search for
>>> supersymmetry
>>> ATLAS_2011_S9225137         High jet multiplicity squark and gluino
>>> search
>>> ATLAS_2012_CONF_2012_001    [PRELIMINARY] 4 or more lepton plus missing
>>> transverse energy SUSY search
>>> ATLAS_2012_CONF_2012_103    [UNVALIDATED] High jet multiplicity squark
>>> and gluino search
>>> ATLAS_2012_CONF_2012_104    [UNVALIDATED] Search for supersymmetry at 8
>>> TeV in final states with jets, missing transverse momentum and one
>>> lepton with the ATLAS detector.
>>> ATLAS_2012_CONF_2012_105    [UNVALIDATED] Search for supersymmetry with
>>> 2 same-sign leptons, jets and missing transverse energy
>>> ATLAS_2012_CONF_2012_109    [UNVALIDATED] 0-lepton squark and gluino
>>> search
>>> ATLAS_2012_CONF_2012_153    [PRELIMINARY] 4 or more lepton plus missing
>>> transverse energy SUSY search
>>> ATLAS_2012_I1095236         [UNVALIDATED] b-jets search for
>>> supersymmetry with 0- and 1-leptons
>>> ATLAS_2012_I1112263         3 lepton plus missing transverse energy SUSY
>>> search
>>> ATLAS_2012_I1117704         High jet multiplicity squark and gluino
>>> search
>>> ATLAS_2012_I1125961         0-lepton squark and gluino search
>>> ATLAS_2012_I1126136         [UNVALIDATED] SUSY Top partner search in
>>> jets with missing transverse momentum
>>> ATLAS_2012_I1180197         [UNVALIDATED] Search for supersymmetry at 7
>>> TeV in final states with jets, missing transverse momentum and isolated
>>> leptons with the ATLAS detector.
>>> ATLAS_2012_I1186556         [UNVALIDATED] Search for a heavy top-quark
>>> partner in final states with two leptons.
>>> ATLAS_2012_I1190891         [UNVALIDATED] 4 or more lepton plus missing
>>> transverse energy SUSY search
>>> ATLAS_2012_I1204447         Inclusive multi-lepton search
>>> ATLAS_2012_I943401          Search for supersymmetry with 2 leptons and
>>> missing transverse energy
>>> ATLAS_2012_I946427          [UNVALIDATED] Search for supersymmetry with
>>> diphotons and mising Transverse Momentum
>>> ATLAS_2014_I1307756         Search for scalar diphoton resonances in
>>> ATLAS at sqrt(()s) = 8 TeV
>>> CMS_2011_S8968497           Measurement of dijet angular distributions
>>> and search for quark compositeness in pp collisions at sqrt(s) = 7 TeV
>>>
>>>
>>> Cheers,
>>> Andy
>>>
>