Les Houches

Preliminary list of topics for 2021

(accessible to everyone, editing rights to conveners and organizers)

Jet substructure techniques:

Interplay of jet substructure with other groups (e.g. jet substructure for EW measurements like VBF, semileptonic VV, etc.)
Snowmass jet substructure report (JSS at future colliders) [work + discussion]
What can we do with previous colliders, in light of the LHC [discussion]
Comparing new unfolding methods
- Accord on unbinned results (?)
Probing the latest MC generators (PB algorithm, PANScales, Deductor…) with jet substructure
- Finite N_C, beyond LL, …

Techniques and calculations for SM phenomenology:

` * Calculations:

expected precision for fundamental Standard Model processes at 14 and 100 TeV; what calculations are needed to match this precision?
2→3 at NNLO; status/challenges/prospects
theory uncertainties; more rigorous estimates? correlations?
theoretically sound definition of FONLL at the differential level, beyond incl. cross sections?

PDFs:
- followup on PDF4LHC15 benchmarking exercise; better understanding of tolerances, tensions
- EW corrections/EW PDFs; how to provide consistent calculations
- small x resummation; what is HERA trying to tell us?
- EIC; what will EIC tell us? how do we prepare for that?

Higgs:
- understanding the SM for high Higgs pT; role of top mass corrections/scheme (MSbar vs on-shell); improving channel sensitivities
- polarisation measurements (for diboson/VBS as well)

Jets:
- flavor tagging of jets; matching what theorists can predict (IR safety) and what experimentalists can measure

Monte Carlo:

Non-perturbative uncertainties
- common hadronisation interface and variations
- theoretical understanding
- differences in tuned comparisons
- pheno impact for certain classes of processes (e.g. VBF/VBS)
Shower accuracy studies
- comparing different schemes on higher orders, evaluate phenomenological impact
- Subleading colour and interplay with colour reconnection
- New sampling methods and algorithms versus machine learning techniques
- Accuracy of merging resummed calculation versus ME+PS paradigms
Photon physics, modelling of fragmentation
Heavy flavour matching
- review of existing measurements
- Connecting precision calculation, fragmentation and decays
- partons at 100 TeV
Common LHC event bazaar
Status and needs for electroweak corrections and radiation in shower algorithms
Machine learning and adaptive Monte Carlo methods

SM Higgs Topics:

ggF
- N3LO PDFs, small-x
- EW corrections
- cuts/differential distributions
B-quark issues
- Ttbb, V+HF, VH
- 4FNS vs 5FNS: bbH, t/H/Z+j QCD EW…
- Flavour jet algo\
ggVV
- Massive results [if we’ll have them, probably yes]
VBF
- Factor vs non-factor: TH vs EXP discussion on cuts etc (especially Run3)
Jet-ology
- NNLO+NLO res, VH+J, NNLO+decay & fiducial studies
HH
- EFTs, H vs HH
In general, EFT fits etc
Exp vs theory efficient information exchange
- Likelihood, discriminators as black box
- Differential distribution. TH insight for measurements…
PS issues (SLC, higher logs…, liaise with QCD)
New opportunity for Run3 (unexplored regions, != cuts etc)
STXS
- for decays - binned proposal
FO/Boosted
- NLO-Improved NNLO HTL predictions for gg → H(→yy)+Jet in the fiducial region, experimental sensitivity to different decay channels as a function of pt
- Mixed QCD-EW contributions to higgs (e.g. 2010.09451, 2007.09813)
Backgrounds
- Predictions+uncertainty models for backgrounds to ttH production: tt+HF, ggH+HF, tt+V, previous proposal was to estimate ttV EW correction in different phase space regions
4FS/5FS
- bbar → higgs (e.g. 2004.04752)
- tHj tZj QCD+EW (e.g. 2006.10086), various 4FS/5FS matching issues to consider
Showers
- New showers, subleading-colour issues with parton showers and possible effects on Higgs physics (PanSccales 2011.10054; Forshaw, Plätzer et al 2003.06400, 2007.09648, 2011.15087, 2012.15215)