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Protomodel Builder

Wolfgang Waltenberger, Andre Lessa, Sabine Kraml

Working principle: The purpose of the Protomodel Builder is to identify potential dispersed signals of new physics in the slew of published LHC results. It employs a random walk algorithm to introduce sets of new particles, dubbed protomodels, which are tested against simplified-model results from ATLAS and CMS, exploiting the SModelS software framework. A combinatorial algorithm identifies the set of analyses and/or signal regions that maximally violates the SM hypothesis, while remaining compatible with the entirety of LHC constraints in our database. Employing a multi-level optimization procedure, we may thus bring to light potential dispersed signals, which might otherwise be missed simply because each individual experimental analysis only looks at a fraction of the LHC data.

Results from section 5.2 of arXiv:2012.12246

Fig. 8 from arXiv:2012.12246

In this paper, we performed 10 runs over the "real" SModelS database (v1.2.4), each employing 50 walkers and 1000 steps/walker. The characteristics of the winning models (i.e. the protomodels with highest test statistic K, shown in Fig. 8 in the paper) from each run can be found here:

real #1 - real #2 - real #3 - real #4 - real #5 - real #6 - real #7 - real #8 - real #9 - real #10

The absolute winner is the hiscore model from run #9 with K=6.9 (see plot on the left).

Closure tests, using the winning model of run #9 above as injected signal:

  • with sampling from signal+background (Fig. 10 in the paper): #1 - #2 - #3 - #4 - #5 - #6 - #7 - #8 - #9 - #10
  • without sampling (technical test, Fig. 11 in the paper): #1 - #2 - #3 - #4 - #5 - #6 - #7 - #8 - #9 - #10

The program code can be found in this github repository; the frozen version used for the paper carries the tag arXiv2012.12246 (n.b. this is "raw" code, not a finished software product).

Finally, an explanatory video recording from the reinterpretation workshop.

Animation videos

The random walks have been visualized in these animation videos:

last update 26-12-2020 by SK