====MC, Tools and ML==== ===Systematic uncertainties [Thurs 14h00-16h00 Auditorium]=== Slack channel: #np-ps-syst-uncs Possible projects: * Shower accuracy and benchmarks * Amplitude evolution, if people are interested * Role and impact of the infrared cutoff, tuning, and uncertainties * A practical approach for experiments * What comparisons make sense - what is available? * Generators wishlist? * Including systematic uncertainties in ML based analysis Interested people: Josh, Simon, Stefan, Vinny, Axel, Aishik, Saptaparna, Andrzej, Ana, Maria V., Gianna, Chris G, Christian P, Max, Peter M **Agreed projects:** - Perturbative benchmarks of showers [Simon, James, Daniel] - NLL, Numerical impacts - Interplay between shower and hadronisation [Simon] - Extending study from LH17 [[https://arxiv.org/abs/1803.07977|arXiv:1803.07977]] - Effective/comprehensive uncertainty band - Uncertainty recommendation using available tools [Josh, Gianna] - Setup 4-point variations of all combinations of shower and hadronisation model - Tune these in a consistent way to get an uncertainty envelope - Tuning strategies [Stefan K] - What is currently done? - Common framework? - Better documentation of existing framework - Benchmark sets of data ===Generator software and computing considerations [Friday 11h00-12h30 Auditorium]=== Slack channel: #gen-soft-comp Possible projects: * Efficiencies * MC reweighting/unweighting * GPU/Vectorisation * Event format/sharing * Containerisation/preservation/reproducibility * Use of ML * Common frameworks Interested people: Josh, Vinny, Andrea, Stefan, Saptaparna, Maria V., Sergio, Chris G, Christian P, Ana, Max, Peter M, Simon, Sudeepan **Agreed projects:** - GPU/Vectorisation/HPC [Josh] - Experience porting codes - Workflows in experiments - How would code be run in practise - How to get/confirm allocations - Sharing of resources between EXP and TH - Computing performance [Josh] - Benchmarking current code - Also with examples from EXP - Accounting in experiments - Projections for future N(2,3)LO calculations - Updates to interfaces [Josh] - Interoperability of models - Modular framework - Multi-event API in MC generators - Resampling - Accessibility of tools [Josh] - Containerisation and reproducibility - Docker images, run cards, Rivet routines, Yoda files -> HepData - Use these tools to make LH studies reproducible - Can at Docker-based workflow on e.g. lxplus be documented to lower barrier to entry for MC studies? - Make sure cards actually used by EXP are uploaded with TH prediction Yoda files. - Make available for benchmarking (c.f. point 2.), including full chain in EXP - MC Generation generic tool/interface - Like MCPlots - Event formats [Josh] - New HDF5 standard <- LHEF/HepMC - Easier event sharing, smaller disk footprint - Need for more information in intermediate stages of generation? - Sample sharing between experiments - Joint/cross validation - ML for MC [] - Interoperability link to point 3. (swapping out parts of generation in modular framework) - Discussion of exact vs approximate use of ML - Resampling/reweighting [Josh] - Reweighting and derivative-based optimisation - Resampling to eliminate negative weights - NN and cell-based tools - Stress tests of these tools? - Problem areas from TH PoV - Validation at scale in EXP ===ttW modelling studies [TBC]=== Slack channel: #ttw Possible projects: * Understanding differences between Sherpa MEPS@NLO and aMC+Py8 FxFx? * Modelling uncertainties? Interested people: Josh, Sergio, Stefan, Gianna ===Issues with EW evolution, identification of EW final states [Thurs 16h00-17h30 QCD room]=== Slack channel: #ew-evo-id * Possibly connecting to ttW? Interested people: Simon, Axel, Andrzej === Interplay between showers and hadronization === * Hadronization model should respond to shower IR cut variations * Study IR ctuoff dependence, map out how purely perturbative variations compare * goal is to update the LH 17 study on retuning with a more solid theory framework Interested: Simon, Andrzej, Stefan K. ===Tuning Accord and Strategies=== * What is currently done: - Common framework for tuning exist, but no single script to run - Nice to have a script, which automatically prints exactly what is done and with which flags - Every generator team does tuning on their own - Almost no documentation on the tunes provided - Rarely publicly available weights - Rarely publicly available tuning options (samples, interpolation order, flags used, ...) - Often post-processing tune by eye * Goals of the project: - Coordination among generator authors of Herwig, Pythia and Sherpa (mattermost channel?) - Common framework for tuning exist, but no single reproducible script: - Stefan K. trying to provide this in Professor, which automatically documents what version, options, flags, etc. are being run - Someone could do something similar in Apprentice - Les Houches Accord on some Benchmark observable+weight sets: - Observable quality & quantity requirements: - No ratio Rivets if full information is available? - Reduce double counting of observables: - No gaps in histogram (see e.g. some ALEPH identified particle momentum distribution) - Smaller bin-width is preferred - Enough statistics: - NOTE: If the errors of the data are to small a theory uncertainty should be provided to the tuning framework otherwise the minimization will likely over-fit this data - Benchmark sets: - Conservative set of selected (IRC safe?) Event Shapes: - Input from perturbative experts needed - Only close to the peak, where hadronization is not dominant - Provide global sets from each generator to gather information - Ultimate goals: - Minimal set of accorded observables+weights among all generators for comparability - Tune using $\chi^2$ (more strict) and $\chi^2/(1+\chi^2)$ (less strict) - Maximal set of accorded observables+weights among all generators for comparability - Tune using $\chi^2$ (more strict) and $\chi^2/(1+\chi^2)$ (less strict) - Provide recommendations to experiments on tuning? - ... Interested: Simon, Andrzej, Stefan K., .... ===Status of q/g discrimination [Weds 14h00-15h30 Library]=== * Linked to Jets and Higgs Interested people: Simon, Andrzej ===Fiducial multiboson cross sections (VBF/VBS) [Thurs 11h00-12h30 QCD room]=== * Linked to Higgs Interested people: Simon, Josh, Stefan, Axel, Saptaparna ===Possible HF review [TBC]=== * Linked with Higgs and Jets Interested people: Josh, Davide?, Stefan ===ML-focused [TBC]=== Possible projects: * New unfolding observables * Interoperability/practical considerations Interested people: Vinny,Josh, Aishik, Andrzej, Maria V., Peter M ===Overlaps between FPF and LHC [TBC]=== Slack channel: #lhc-fpf (Possibly the same for DUNE and EIC if enough people are here?) Possible projects: * Impact of NNPDF + FPF data on LHC precision, e.g. W-mass Interested people: Josh, Maria V., Stefan, Peter M (EIC)