Mass methods
From Wiki Les Houches 09
(Difference between revisions)
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| <math>M_{eff}</math> | | <math>M_{eff}</math> | ||
| hep-ph/9610544[http://arxiv.org/abs/hep-ph/9610544], hep-ph/0006276[http://arxiv.org/abs/hep-ph/0006276] | | hep-ph/9610544[http://arxiv.org/abs/hep-ph/9610544], hep-ph/0006276[http://arxiv.org/abs/hep-ph/0006276] | ||
- | | Discovery of | + | | Discovery of NP with massive particles. |
| Bad, quoted to be 20%-50% on masses in references, but needs to be interpreted in a specific model. | | Bad, quoted to be 20%-50% on masses in references, but needs to be interpreted in a specific model. | ||
| Discovery above SM contribution and estimating mass scale of particles with dominant cross section. | | Discovery above SM contribution and estimating mass scale of particles with dominant cross section. | ||
Line 28: | Line 28: | ||
| <math>Edges</math> | | <math>Edges</math> | ||
| hep-ph/9610544[http://arxiv.org/abs/hep-ph/9610544] (lots) | | hep-ph/9610544[http://arxiv.org/abs/hep-ph/9610544] (lots) | ||
- | | | + | | Cascade decay chains. Gives one relationship between NP masses per pair of visible final state particles. |
- | | | + | | Quoted as 4% on LSP in fast simulation pheno study of SPS1a, hep-ph/0410303 [http://arxiv.org/abs/hep-ph/0410303] |
| Mass differences in leptonic decays. | | Mass differences in leptonic decays. | ||
- | | Dependence on mass scale is weak. | + | | Dependence on absolute mass scale is weak. Can be fooled by false solutions. |
| Intermediate 3-body decays? Combinatoric (other side) jets not considered. Calorimeter nonlinearity? | | Intermediate 3-body decays? Combinatoric (other side) jets not considered. Calorimeter nonlinearity? | ||
|- | |- |
Revision as of 16:31, 24 June 2009
Variable/Method | Reference(s)/Code | Realm of Applicability | Precision | Good for | Fails for | Unknown/Future directions |
---|---|---|---|---|---|---|
MT | (ancient) | one missing particle | ||||
Meff | hep-ph/9610544[1], hep-ph/0006276[2] | Discovery of NP with massive particles. | Bad, quoted to be 20%-50% on masses in references, but needs to be interpreted in a specific model. | Discovery above SM contribution and estimating mass scale of particles with dominant cross section. | Does not identify process, but gives some information on particle content of dominant topologies. | |
HT | always | does not identify process in any way | ||||
Edges | hep-ph/9610544[3] (lots) | Cascade decay chains. Gives one relationship between NP masses per pair of visible final state particles. | Quoted as 4% on LSP in fast simulation pheno study of SPS1a, hep-ph/0410303 [4] | Mass differences in leptonic decays. | Dependence on absolute mass scale is weak. Can be fooled by false solutions. | Intermediate 3-body decays? Combinatoric (other side) jets not considered. Calorimeter nonlinearity? |
MT2 | hep-ph/9906349[5] | |||||
MT2 kink ("stransverse" mass) | arXiv:0709.0288[6] | 4-body final state, 2 missing | large mass differences and large pT | small mass differences or no pT | ||
MTn | 4-body final state, n missing | |||||
MTgen | arXiv:0708.1028[7] | |||||
M2C | arXiv:0712.0943[8] | |||||
M3C | arXiv:0811.2138[9] | |||||
arXiv:0812.1042[10] | ||||||
Exactly-constrained Polynomials | arXiv:0707.0030[11] | 4 on-shell intermediate resonances, 2 missing | Apply to squark-neutralino2-slepton-neutralino1 cascade where other side is squark-neutralino1. | |||
Multi-event Polynomial intersection | arXiv:0802.4290[12] | 5 or more on-shell intermediate resonances, 2 missing | Statistics of histograms created with n-event subsets; If mass differences are fixed and the masses are increased, what happens? (Sabine Kraml); Develop methods for asymmetric chains and < 6 intermediate resonances. |
- How can we define "Precision" in a manner that lets us meaningfully compare different methods? A lot of process-specific assumptions and backgrounds usually enter the application of each method.
- In general, all methods need to be systematically tested in cases where the assumptions needed for the method are not satisfied.
- Appropriate consideration of ISR/FSR jets is not usually considered. Requires 2->3 matrix elements where the hard scattering process includes a possible extra hard quark/gluon radiation.