QCD@LHC 2026

Session

New techniques, tools and generators

28 Sept 2026, 16:00

University of Oxford

21. "Hadron-in-fat-jet'' AI Tagging to Detect Rare Decays

Mr Linrui Chen (Peking University), Qiang Li (Peking University (CN)), Youpeng Wu (Peking University (CN))

New techniques, tools, and generators

Standard slot

We investigate a novel class of boosted-object signatures at the LHC, where a high-pT fat-jet contains an identifiable hadron or quarkonium state originating from rare or semi-exclusive decays. Unlike conventional boosted jet studies, which focus on multi-prong partonic substructure, our approach probes hybrid configurations such as W±→π±γ, where a localized hadronic or quarkonium signal is...

49. (YSF) Advances in Hadronic Tau Reconstruction and Identification in ATLAS Using Graph Neural Networks

ATLAS Collaboration

New techniques, tools, and generators

Standard slot

Hadronically decaying tau leptons are essential signatures in many ATLAS measurements and searches, including studies of the Higgs boson and potential new physics. Their identification is particularly challenging due to the large background from quark and gluon initiated jets in proton-proton collisions. This poster presents an overview of hadronic tau reconstruction and identification in the...

127. A first glimpse of matching beyond NLO with logarithmically accurate showers

Nicolas Francois Schalch (University of Oxford (GB))

New techniques, tools, and generators

Standard slot

The increasing precision at collider experiments calls for theoretical predictions that combine fixed-order accuracy with the fully exclusive description of final states provided by parton showers. Achieving this combination beyond next-to-leading-order remains a major challenge, in particular while preserving the logarithmic accuracy of the shower.
In this talk, we present first results...

76. DIS-secting the universe with high-energy neutrinos

Lorenzo Guerra (Max Planck Institute for Physics)

New techniques, tools, and generators

Standard slot

We revisit the impact of electroweak (EW) radiative corrections on the kinematic distributions of charged leptons in neutrino-induced Charged-Current (CC) Deep Inelastic Scattering (DIS). We implement full Next-to-Leading Order (NLO) EW corrections to CC DIS in a flexible Monte Carlo framework, supplemented with higher-order logarithmically enhanced final-state QED radiation. We compare our...

93. Double-real corrections to color singlet decay in a parton-shower inspired scheme

Max Knobbe (Fermilab)

New techniques, tools, and generators

Standard slot

We introduce a local infrared subtraction method for next-to-next-to-leading order QCD calculations in color singlet decays, with counterterms based on scalar radiators and pure splitting functions. Overlapping singularities in the multipole radiation pattern are disentangled by partial fractioning, and the kinematics mapping corresponds to iterated next-to-leading order kinematics. We verify...

89. Quarkonium parton shower in Herwig 7

Aidin Masouminia (IPPP, Durham University)

New techniques, tools, and generators

Standard slot

I will present the implementation of a fully automated quarkonium parton shower in Herwig 7 based on non-relativistic QCD factorisation with explicit spin and colour projections. The framework incorporates both colour-singlet and colour-octet production channels, including gluon fragmentation and diquark production, and combines perturbative short-distance coefficients with non-perturbative...

124. Resummed Distribution Functions: Making Perturbation Theory Normalized and Positive

Rikab Gambhir (University of Cincinnati)

New techniques, tools, and generators

Standard slot

Fixed-order perturbative calculations for differential cross sections can suffer from non-physical artifacts: they can be non-positive, non-normalizable, and non-finite, none of which occur in experimental measurements. We propose a framework, the Resummed Distribution Function (RDF), that, given a perturbative calculation for an observable to some finite order in αs, will ``resum'' the...

84. Scaling Neural Simulation Based Inference to Large Datasets

Chris Pollard (University of Warwick (GB))

New techniques, tools, and generators

Standard slot

Neural simulation-based inference (NSBI) in HEP predominantly relies on event-level likelihood or likelihood-ratio estimators. In non-trivial settings, these require expensive post-hoc profiling or marginalization over nuisance parameters to perform dataset-wide inference. We introduce PAIRS, a two-stage procedure that learns an event representation from small datasets ($N \le 2$). Under mild...

101. Status of the Alaric Parton Shower

Daniel Reichelt

New techniques, tools, and generators

Standard slot

In this talk I will present the status of the Alaric parton shower. I will discuss new results including matching to NLO, spin correlations and resonance and width aware matching strategies for $t\bar{t}$ production.