[Rivet] Question on searches in rivet

[Andy Buckley]

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
>>
> 


-- 
Dr Andy Buckley, Royal Society University Research Fellow
Particle Physics Expt Group, University of Glasgow / PH Dept, CERN