NLO Multi-leg
From Wiki Les Houches 09
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| - | 1. Collecting results of completed higher order calculations | + | '''1. Collecting results of completed higher order calculations''' |
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The idea is to collect in a table the cross section predictions for relevant LHC processes where available. Tree-level results should be compared with higher order | The idea is to collect in a table the cross section predictions for relevant LHC processes where available. Tree-level results should be compared with higher order | ||
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A collection of plots showing distributions of relevant observables comparing tree and higher order corrections may also be compiled. | A collection of plots showing distributions of relevant observables comparing tree and higher order corrections may also be compiled. | ||
| - | 2. Higgs cross sections in and beyond the Standard | + | '''2. Higgs cross sections in and beyond the Standard Mode'''l |
This issue is too important to be just a sub-part of point 1. Note that in former workshops a separate Higgs working group did exist. Special attention will be given to higher | This issue is too important to be just a sub-part of point 1. Note that in former workshops a separate Higgs working group did exist. Special attention will be given to higher | ||
order corrections of Higgs observables in BSM scenarios (coordinated with the BSM group). | order corrections of Higgs observables in BSM scenarios (coordinated with the BSM group). | ||
| - | 3. Identifying/analysing observables of interest | + | '''3. Identifying/analysing observables of interest''' |
Of special interest are observables which have an improved scale dependence, e.g. ratios of cross sections. Classical examples are W/Z and the dijet ratio. New ideas and proposals | Of special interest are observables which have an improved scale dependence, e.g. ratios of cross sections. Classical examples are W/Z and the dijet ratio. New ideas and proposals | ||
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examples are jet sub-structure, boosted tops, dijet delta-phi de-correlation... This topic has some overlap with the BSM searches and inter-group activity would be welcome. | examples are jet sub-structure, boosted tops, dijet delta-phi de-correlation... This topic has some overlap with the BSM searches and inter-group activity would be welcome. | ||
| - | 4. Identifying important missing processes | + | '''4. Identifying important missing processes''' |
The Les Houches wishlist from 2005/2007 is filling up slowly but progressively. Progress should be reported and a discussion should identify which key processes should be added to | The Les Houches wishlist from 2005/2007 is filling up slowly but progressively. Progress should be reported and a discussion should identify which key processes should be added to | ||
the list. This may also include relevant NNLO corrections. This effort will result in an updated Les Houches list. | the list. This may also include relevant NNLO corrections. This effort will result in an updated Les Houches list. | ||
| - | 5. Standardization of NLO computations | + | '''5. Standardization of NLO computations''' |
A standarization of NLO computations has, of course, may aspects. Different groups would benefit from the possibility to use and exchange different public symbolic/numerical routines to | A standarization of NLO computations has, of course, may aspects. Different groups would benefit from the possibility to use and exchange different public symbolic/numerical routines to | ||
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defined which could be used in combination with existing event ntuples. | defined which could be used in combination with existing event ntuples. | ||
| - | 6. IR-safe jet algorithms | + | '''6. IR-safe jet algorithms''' |
Detailed understanding of jet algorithms will play an important role in the LHC era. Much progress has been made in the last several years concerning IR-safe jet algorithms. Studies and | Detailed understanding of jet algorithms will play an important role in the LHC era. Much progress has been made in the last several years concerning IR-safe jet algorithms. Studies and | ||
Revision as of 18:42, 31 December 2008
Les Houches topics for WG1 (Standard Model and NLO Multi-leg: Session 1 only)
1. Collecting results of completed higher order calculations
The idea is to collect in a table the cross section predictions for relevant LHC processes where available. Tree-level results should be compared with higher order
predictions (whatever is known). The table should also contain information on scale and pdf uncertainties. The inclusive case may be compared with standard selection
cuts.
Producing such a table would, of course, include a detailed comparison of results originating from different groups.
A collection of plots showing distributions of relevant observables comparing tree and higher order corrections may also be compiled.
2. Higgs cross sections in and beyond the Standard Model
This issue is too important to be just a sub-part of point 1. Note that in former workshops a separate Higgs working group did exist. Special attention will be given to higher order corrections of Higgs observables in BSM scenarios (coordinated with the BSM group).
3. Identifying/analysing observables of interest
Of special interest are observables which have an improved scale dependence, e.g. ratios of cross sections. Classical examples are W/Z and the dijet ratio. New ideas and proposals are welcome.
Another issue is to identify jet observables which have no strong dependence on the absolute jet energy, as this will not be measured very precisely during the early running. Recent examples are jet sub-structure, boosted tops, dijet delta-phi de-correlation... This topic has some overlap with the BSM searches and inter-group activity would be welcome.
4. Identifying important missing processes
The Les Houches wishlist from 2005/2007 is filling up slowly but progressively. Progress should be reported and a discussion should identify which key processes should be added to the list. This may also include relevant NNLO corrections. This effort will result in an updated Les Houches list.
5. Standardization of NLO computations
A standarization of NLO computations has, of course, may aspects. Different groups would benefit from the possibility to use and exchange different public symbolic/numerical routines to perform computations. Given the boost such an initiative may induce in the field, such a discussion is highly relevant. An agreement to submit results/tools/code to certain databases for storing and accessing (e.g. under HEPTOOLS, HEPCode web pages) would already be progress, but is only one aspect of the issue.
For NLO computations, there is a natural split between real and virtual corrections. One could agree on finite output formats for both sectors, such that event re-weighting functions could be defined which could be used in combination with existing event ntuples.
6. IR-safe jet algorithms
Detailed understanding of jet algorithms will play an important role in the LHC era. Much progress has been made in the last several years concerning IR-safe jet algorithms. Studies and comparisons of different jet algorithms in the NLO context are highly welcome. Of particular interest is how the observables map from the parton level inherent in the pQCD approach to the particle/detector level.
7.l
