2013:groups:np:susysms
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2013:groups:np:susysms [2013/06/20 12:14] sabine.kraml |
2013:groups:np:susysms [2013/10/30 11:12] (current) sabine.kraml |
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| ====== Simplified models in the SUSY context ====== | ====== Simplified models in the SUSY context ====== | ||
| - | Interested people: Suchita, Wolfgang, Sabine, Aoife .... (please add your name!) | + | Interested people: Suchita, Wolfgang, Sabine, Aoife, Sofio, Tobias .... (please add your name!) |
| - | Contact person: Suchita | + | {{:2013:participants:sms_wishlist_kulkarni.pdf | SMS wishlist talk}} |
| - | + | ||
| - | [[sms_wishlist_kulkarni.pdf | SMS wishlist talk]] | + | |
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| The following wish list is based on this principle and aims towards making the simplified models results more accessible and useful. For each of the points on the wish list, we list one potential candidate where the existing SMS results can be improved. | The following wish list is based on this principle and aims towards making the simplified models results more accessible and useful. For each of the points on the wish list, we list one potential candidate where the existing SMS results can be improved. | ||
| - | * Availability of information in digital formats | + | - **Digitize... digitize... digitize....**\\ Please provide the information contained in the cross section limit plots in electronic form, either as simple ascii file or a Root file. This is increasingly done by CMS, a good example is [[https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsSUS13011#|SUS13011]], ATLAS is still dragging behind. (this is gradually improving...)\\ \\ |
| - | * Digital access to 95% CL UL for a SMS result along with the observed and the expected exclusion lines should be possible via a root or a text file | + | - **For topologies involving cascade decays, provide results for more than one (at least 3) intermediate mass values.**\\ Results on processes involving 2-step decays (e.g. trileptons from EWino decays via sleptons) crucially depend on the intermediate mass value, because this determines the kinematics of the events. If results are given for only one mass fraction value, we cannot use them, because we cannot interpolate. This is for example the case for the 3taus+MET results from CMS, [[https://twiki.cern.ch/twiki/pub/CMSPublic/PhysicsResultsSUS12022/exclusion_TChiStauSnu_0_5.png|SUS12022]], which are available for x=0.5 only. Such results which have only one value of x are in fact completely useless for our purpose. In order to allow interpolation for different intermediate mass values, least three mass fraction are needed. We recommend to provide the results for x = 0.05, 0.5, 0.95 (or if possibe x = 0.05, 0.25, 0.5, 0.75, 0.95).\\ \\ |
| - | * eg. [[https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsSUS13011#]] | + | - **Provide good coverage of the parameter space considered**\\ Large changes in the excluded cross sections (or holes in the parameter space), as present e.g. in [[https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2013-035/figaux_01a.png|this example]] from the EWino search in ATLAS, cannot be reliably interpolated. Please provide uniform bins or, if this is not feasible, ensure a good coverage of the sensitive region.\\ \\ |
| - | * For topologies involving more than two free parameters 95% CL UL should be given for more than one values of free parameter. eg. 1-step cascade decays involve mass of intermediate particle in addition to the mass of mother and LSP, at least three mass fraction slice results should be available eg. x = 0.05, 0.5, 0.95 or x = 0.25, 0.5, 0.75 | + | - **Avoid too restrictive assumptions**\\ When presenting an SMS interpretation result, the underlying physics considered should be as generic as possible. Instead of fixing certain aspects of the scenario, it would be more helpful to discuss "default" and extreme cases. For example: |
| - | * eg. [[https://twiki.cern.ch/twiki/pub/CMSPublic/PhysicsResultsSUS12022/exclusion_TChiStauSnu_0_5.png]] results available only for x = 0.5, although for other cases of slepton mediated weakino decays more values of x are considered | + | * Same-sign leptons plus jets from gluino and squark production: in [[https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2013-007/fig_16.png|Fig. 16]] of ATLAS-CONF-2013-007, two mass parameters are fixed (see point 2. above), and flavor-democratic slepton decays are assumed --> Suchita's nightmare analysis. |
| - | * It should be possible to reliably interpolate upper limits between two different points in a SMS result plot | + | * On the other hand, the CMS search for electroweak production of charginos, neutralinos and sleptons using leptonic final states, [[https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsSUS12022|SUS12022]], discusses several extreme cases for slepton decays, which is a more helpful approach.\\ \\ |
| - | * eg. [[https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2013-035/figaux_01a.png]] large changes in the UL, such as ones represented in this example, can not be interpolated | + | - **For topologies involving different decays on each leg, parametrize results in terms of branching fractions.**\\ A typical example is stop1 pair production with one stop decaying into top+neutralino1 and the other one into bottom+chargino1. The final state is tb+MET, but the constraints on the cross section depend on 3 masses (stop1, chargino1, neutralino1) as well as the 2 branching ratios. If only the two decay channels are open, BR(stop1 --> bottom+chargino1) = 1-BR(stop1 --> top+neutralino1), leaving us with 4 free parameters. It would be useful to present results in, e.g., the stop1 versus neutralino1 mass plane for different values of branching ratios.\\ \\ |
| - | * When presenting an SMS interpretation result, the underlying physics considered should be as generic as possible. Instead of fixing certain aspects of the scenario, it might be more helpful to discuss "default" and extreme cases: | + | - **Give expected upper limits on sigma x BR in addition to the observed ones**\\ The expected upper limits are needed in order to identify the most sensitive topology. This is crucial for a correct statistical treatment of complex spectrum decompositions, which may be constrained by more than topology.\\ \\ |
| - | * eg. [[https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/CONFNOTES/ATLAS-CONF-2013-007/fig_16.png]]: two mass parameters are fixed (see item one in our wishlist), and democratic slepton decays are assumed. On the other hand, [[https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsSUS12022]] discusses several extreme cases for slepton decays, which is a more helpful approach. | + | - **Incorporate likelihoods**\\ An approximate form of the final likelihood (e.g. through RooFit/RooStats) or at least more than one CL UL on the cross sections would be extremely welcome. This would help e.g. assessing which topologies should be combined.\\ |
| - | * Expected upper limits on sigma X BR are needed in order to identify the most sensitive topology | + | |
| - | * For every 95% CL observed UL plot, the expected UL plot is desirable (as additional material in digital format) | + | |
| - | * Efficiency maps should be made available from experimental collaborations | + | |
| + | Finally we note that **efficiency maps** would be very useful for enlarging the scope of SMS interpretations, cf [[https://indico.cern.ch/conferenceOtherViews.py?confId=272303|CERN workshop]]. | ||
2013/groups/np/susysms.1371723246.txt.gz · Last modified: 2013/06/20 12:14 by sabine.kraml
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