User Tools

Site Tools


2023:groups:smhiggs:higgs-cell-resample:start

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
2023:groups:smhiggs:higgs-cell-resample:start [2023/06/16 09:27]
stephen.jones
2023:groups:smhiggs:higgs-cell-resample:start [2023/06/18 16:23] (current)
stephen.jones
Line 1: Line 1:
-===== Negative Weight Mitigation for Higgs Signal/​Background =====+===== Negative Weight Mitigation ​(also for Higgs Signal/​Background?) =====
  
-== Topics ==+**Code**: [[https://​github.com/​a-maier/​cres|cres]] 
 + 
 +== Specific ​Topics ==
   * Apply cell resampling ([[https://​arxiv.org/​abs/​2109.07851|paper 1]] [[https://​arxiv.org/​abs/​2303.15246|paper 2]] [[https://​github.com/​a-maier/​cres|source]] [[https://​cres.hepforge.org/​|binaries]]) to Higgs signal/​background (closure tests, measure of simplification e.g. #event reduction)   * Apply cell resampling ([[https://​arxiv.org/​abs/​2109.07851|paper 1]] [[https://​arxiv.org/​abs/​2303.15246|paper 2]] [[https://​github.com/​a-maier/​cres|source]] [[https://​cres.hepforge.org/​|binaries]]) to Higgs signal/​background (closure tests, measure of simplification e.g. #event reduction)
 +  * Graph of fraction of negative weights for Higgs processes/​background (slide 5/9 [[https://​phystev.cnrs.fr/​wiki/​_media/​2023:​cell_resampling.pdf|Jeppe talk]])
  
 == Processes == == Processes ==
 +  * di-photon NLO sample (m_gamgam centred around Higgs mass window)
 +
 +== General Topics ==
 +  * Discussion on good metrics (what to compare before considering events close)
 +  * Measure the impact on reals vs virtuals, which events are most likely to be altered and by how much?
 +  * Try it on proper experimental samples (what metric is good, what issues arise?)
 +  * Applying this to NNLO (e.g. HighTea samples)
 +  * Try e.g. jpsi->​leptons something very narrow (technical issues regarding IR sensitivity,​ modifying distributions...)
 +  * Plots of mean/​median/​width of the cell resampling bins, studying these distributions and their potential impact
 +  * Can narrow weight distribution for more efficient event unweighting
 +
 +== Talk Discussion (winner: most questions per talk) ==
 +  * Q: why is w+5 improving more than z+3? 
 +    - initial event sample size? (no, both have 1e9)
 +    - dipole cut vs improvement?​ (check dipole cut used)
 +  * Q: calculating density of events to "​pre-check"​ that this algorithm may work?
 +  * Q: metric needs to be compatible with how ps generator is populating ps, proof that this is not biasing anything?
 +  * Q: should there be a bias towards positive values (since you iteratively add nearest event until wi>=0)?
 +    - ps generator dependent because this alters which events are clustered, can this have an impact on the physics?
 +  * Q: plotting statistical uncertainties on the original sample ​
 +    - more easily allows verifying that differences are within statistical uncertainty
 +  * Q: on which type of event does this have the biggest impact?
 +    - imagine reals are more impacted than virtual ​
 +    - we were completely agnostic
 +  * Q: can we really prove that this does not alter distributions?​ (prove that you preserve distributional structure of the observables you compute)
 +    - we do not alter any of the event kinematics
 +    - there is no cross talk of events separated by more than the maximum allowed distance
 +    - IRC safe measure important, but this is not a sufficient condition, can you reproduce infrared sensitive observables (e.g. Sudakov shoulder, 0-bin of ptZ), can your smearing reproduce this feature in the limit that the smearing goes to 0?
 +  * Q: mean/​median/​width of the cell resampling bins
 +    - we have plots that we can examine
 +
2023/groups/smhiggs/higgs-cell-resample/start.1686900469.txt.gz · Last modified: 2023/06/16 09:27 by stephen.jones