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 New Physics with massive particles |
| - | | | + | | Bad, quoted to be 20%-50%, but needs to be interpreted in a specific model. |
| - | | | + | | Estimating mass scale of particles with dominant cross section. |
| - | | | + | | Does not identify process, but gives some information on particle content of dominant topologies. |
|- | |- | ||
| <math>H_T</math> | | <math>H_T</math> | ||
Revision as of 16:05, 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 New Physics with massive particles | Bad, quoted to be 20%-50%, but needs to be interpreted in a specific model. | 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 | (lots) | Mass differences in leptonic decays. | Dependence on mass scale is weak. | Intermediate 3-body decays? Combinatoric (other side) jets not considered. Calorimeter nonlinearity? | ||
| MT2 | hep-ph/9906349[3] | |||||
| MT2 kink ("stransverse" mass) | arXiv:0709.0288[4] | 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[5] | |||||
| M2C | arXiv:0712.0943[6] | |||||
| M3C | arXiv:0811.2138[7] | |||||
| arXiv:0812.1042[8] | |||||
| Exactly-constrained Polynomials | arXiv:0707.0030[9] | 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[10] | 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.
