QCD@LHC 2025

8 Sept 2025, 08:00 → 12 Sept 2025, 19:15 US/Eastern

Charles B. Wang Center, Stony Brook University

Felix Ringer (Stony Brook University), Robert Szafron (Brookhaven National Laboratory), Valerio Dao (Stony Brook University)

Towards a Unified Understanding of QCD: LHC Meets EIC

The 15th edition of QCD@LHC, aimed at fostering discussions and collaboration between experimenters and theorists working on strong interactions at the LHC, will be held in Stony Brook, New York
This year, the conference will broaden its scope to include EIC physics and perspectives, encouraging dialogue on the interplay between QCD studies at the LHC and the emerging opportunities at the Electron-Ion Collider at BNL.

Topics:

• Perturbative and resummed predictions, parton showers and event generators for LHC and EIC

  Conveners: Sebastian Jaskiewicz, Luca Buonocore, Mario Pelliccioni, Philip Sommer
  
  

• Polarized deep-inelastic physics

  Conveners: Tommaso Rainaldi, Shohini Bhattacharya, Wim Cosyn
  
  

• Parton distribution functions

  Conveners: Nobuo Sato, Francesco Giuli, Juan Cruz Martinez, Katarzyna Wichman
  
  

• Soft interactions, non-perturbative QCD

  Conveners: Matt LeBlanc, Alba Soto Ontoso, Soumya Mohapatra
  
  

• Higgs, electroweak, BSM physics

  Conveners: Hannah Arnold, Gaetano Barone, Clara Del Pio
  
  

• Heavy Quarks (including top and flavour physics)

  Conveners: Philipp Boeer, Andrii Usachov, Peter Berta, Sergio Sanchez Cruz, Fabrizio Grosa

 

Agenda can be found at: https://indico.cern.ch/event/1462029/

International Advisory Committee:

Sergey Alekhin (Hamburg), Johannes Blümlein (DESY), Claude Duhr (Bonn), Keith Ellis (Durham), Thomas Gehrmann (Zürich), Nigel Glover (Durham), Joey Huston (Michigan State), Judith Katzy (DESY), Frank Krauss (Durham), Jean-Philippe Lansberg (Orsay), Fabio Maltoni (Louvain), Michelangelo Mangano (CERN), Zoltan Nagy (DESY), Eram Syed Rizvi (QMUL), Frank Siegert (Dresden), Dominik Stöckinger (Dresden), Zoltan Trocsanyi (Budapest), Doreen Wackeroth (Buffalo), Ciaran Williams (Buffalo)

Local Organizing Committee:

Co-Chairs: Valerio Dao (SBU), Felix Ringer (SBU), Robert Szafron (BNL)

Members: Elke Aschenauer (BNL), Abhay Deshpande (BNL/SBU),Sergey Syritsyn (SBU), George Sterman (SBU)

 

Poster.pdf

Monday 8 September

08:00 → 08:55 Registration

08:55 → 10:30 Plenary: Plenary 1

Convener: Robert Szafron (Brookhaven National Laboratory)

08:55 Welcome

Speakers: Robert Szafron (Brookhaven National Laboratory), Valerio Dao (Stony Brook University)

video2210721253.mp4

Welcome to QCD@LHC 2025.pdf

09:00 Opening

Speaker: George Sterman

QCD @ LHC 2025 welcome.pdf

09:30 Jet Physics at LHC and EIC

Speaker: Jennifer Roloff (Brown University (US))

qcdAtlhc_stonybrook.pdf

10:00 Toponium at the LHC

Speaker: Giulia Negro (Purdue University (US))

toponium_Negro_8Sep2025.pdf

10:30 → 11:00 Coffee Break

11:00 → 12:30 Plenary: Plenary 2

Convener: Sally Dawson (BNL)

11:00 Recent Higgs results from LHC

Speaker: Michele D'Andrea (INFN e Universita Genova (IT))

Recent Higgs measurements at LHC NEW.pdf

11:30 Results from Cold QCD at RHIC

Speaker: Xiaoxuan Chu

qcd_lhc_xchu.pdf

12:00 From Color to Confinement: Studying Hadronization at the LHC and EIC

Speakers: Christine Aidala (University of Michigan (US)), Prof. Christine Aidala

AidalaQCDatLHC.pdf

12:30 → 14:00 Lunch Break

14:00 → 15:30 Plenary: Plenary 3

Convener: Valerio Dao (Stony Brook University)

14:00 Global Analyses of Parton Distribution Functions: Status and Prospects

Speaker: TIMOTHY J HOBBS (Argonne National Laboratory)

Hobbs_QCDLHC_25.pdf

14:30 The Spin Structure of the Nucleon

Speaker: Dr Jianwei Qiu (Jefferson Lab)

Qiu-LHC2EIC.pdf

15:00 Theory developments for the EIC

Speakers: Daniel De Florian, Daniel De Florian (International Center for Advanced Studies (AR)), Daniel De Florian (Laboratorio de Fisica Teorica Departamento de Fisica), Daniel de Florian (Universidad de Buenos Aires)

eic.pdf

15:30 → 16:00 Coffee Break

16:00 → 17:30 Plenary: Plenary 4

Convener: Valerio Dao (Stony Brook University)

16:00 Parton Showers and Resummation for EIC and LHC

Speaker: Melissa Corona van Beekveld (Nikhef National institute for subatomic physics (NL))

QCDatLHC2025_showers_resummation.pdf

16:30 Theory ingredients for precision mW at the LHC

Speaker: Kenneth Long (Massachusetts Inst. of Technology (US))

2025_09_08_Long_mW_QCDatLHC.pdf

17:00 Impact of scale and PDF uncertainties on measurements at the LHC

Speaker: Erik Bachmann (Technische Universitaet Dresden (DE))

2025-09-08 QCD@LHC Bachmann.pdf

17:30 → 19:00 Reception

Tuesday 9 September

09:00 → 10:30 Heavy Quarks (including top and flavour physics): Parallel 1A

Conveners: Fabrizio Grosa (CERN), Philipp Böer

09:23 Heavy-flavour results from ATLAS experiment

This presentation will highlight recent advances in heavy-flavour physics achieved with Run-2 data. It will focus on the latest results in heavy-flavour hadron production and decay measurements, as well as the spectroscopy of exotic heavy-flavour states. Key topics include the most precise determination of the B0 meson lifetime, measurements of charmed meson production cross-sections, and investigations of resonant structures in the di-charmonium mass spectrum.

Speaker: Josef Daniel Sorenson (University of New Mexico (US))

QCDLHC2025_Final.pdf

09:45 Heavy-flavour production measurements with ALICE at the LHC

Open heavy-flavour hadrons are one of the key diagnostic tools available to study the dense, hot, and strongly interacting matter formed in heavy-ion collisions. The charm and beauty quarks are produced mainly in hard parton scatterings at the early stages of the collisions. Measurements of their production in proton–proton (pp) collisions are an important test of perturbative Quantum Chromodynamics (pQCD) calculations and serve as a reference for heavy-ion collisions.

Recent observations at the Large Hadron Collider (LHC) have revealed a significant enhancement in baryon production in hadronic collisions compared to electron–positron and electron–proton collisions. This challenges the conventional assumption of fragmentation universality. This phenomenon, initially highlighted in the charm sector, has also been seen in the beauty sector, suggesting broader implications for heavy-flavour hadronisation processes. To better understand these observations, multiplicity dependent measurements are carried out to investigate hadronisation mechanisms and characterise multiparton interactions, searching for possible connections between small and extended interacting systems.

In addition to single-particle observables, heavy-flavour production can also be explored through particle pairs. The study of angular correlations between charmed hadrons and charged particles provides a powerful tool for investigating charm-quark production and fragmentation. Furthermore, the production of heavy-flavour hadron pairs offers a unique opportunity to study Double Parton Scattering (DPS), a process in which two independent parton–parton scatterings take place within a single pp collision.

This contribution presents the latest measurements of strange ($\Xi_\mathrm{c}^{0,+}$, $\Omega_\mathrm{c}^{0}$, $\mathrm{D_s}^+$, $\mathrm{D_{s1}}(2536)^+$, $\mathrm{D_{s2}}^{*}(2573)^+$) and non-strange ($\Lambda_\mathrm{c}^+$, $\Sigma_\mathrm{c}(2455)^{0,++}$, $\Sigma_\mathrm{c}(2520)^{0,++}$, $\mathrm{D}^{0,+}$) charm-hadron production, as well as non-strange B mesons and $\mathrm{B_s^0}$ mesons in pp collisions at $\sqrt{s} = 13.6$ TeV, recorded by the ALICE experiment during LHC Run 3. We also report new results on the production of charm-hadron and quarkonium pairs, specifically D$^0$D$^0$ and D$^0$J/$\psi$, as well as angular correlations involving $\mathrm{D_s}^+$-hadron and $\Lambda_\mathrm{c}^+$-hadron pairs in pp collisions at $\sqrt{s} = 13.6$ TeV. Selected results from Run 2 on charm-hadron production are included for comparison. Detailed comparisons with model expectations are presented to provide further insights into heavy-flavour production and hadronisation.

Speaker: Tiantian Cheng (Fudan University)

QCD_LHC_TCheng_Final.pdf

10:07 Heavy-hadron production based on kt​-factorization with scale-dependent fragmentation functions

We present a comprehensive study of heavy-hadron production, including $D$ and $B$ mesons, heavy baryons, and the $B_c$ meson. Our calculations are based on the $k_t$-factorization and scale-dependent fragmentation functions, completing the program of implementing this formalism within a variable-flavor-number scheme, as initiated in Phys. Rev.D 104 (2021) 9 094038. Special emphasis is placed on the gluon-to-heavy-hadron contribution, which improves the description of data at small transverse momenta.

Speaker: guiot benjamin (Universidad frederico santa maria)

QCD@LHC2025.pdf

09:00 → 10:36 Parton distribution functions: Parallel 1A

09:00 The complete O(\alpha_s^3) unpolarized and polarized single and two-mass heavy flavor corrections to DIS and the VFNS

After 16 years of work, we have compled the O(\alpha_s^3) unpolarized and polarized single and two-mass heavy flavor corrections to DIS and the VFNS. In course of this we have developed various new field-theoretic, mathematical and computational technologies.

Speaker: Prof. Johannes Bluemlein

QCDLHC25.pdf

09:30 PDFs at the EIC and other future DIS machines, and the impact on LHC physics

Speaker: Claire Gwenlan (University of Oxford (GB))

QCD@LHC25-PDFs-Gwenlan.pdf

09:50 PDF and alpha_s measurements at EIC

Speakers: Zuhal Seyma Demiroglu (Stony Brook University), Zuhal Seyma Demiroglu (Stony Brook University)

alphas_9Sep2025_ZSDemiroglu.pdf

10:10 Precise Determination of the Strong Coupling Constant from Dijet Cross Sections up to the Multi-TeV Range

We determine the value of the strong coupling α_s and study its running over a wide range of scales as probed by the dijet production process at hadron colliders. The analysis is performed using the complete next-to-next-to-leading order (NNLO) predictions in perturbative QCD and is based on dijet data published by ATLAS and CMS at center-of-mass energies of 7, 8, and 13 TeV. From a large subset of these data we infer a value of α_s(m_Z)=0.1178±0.0022 for the strong coupling at the scale of the Z-boson mass m_Z.

Complementing the LHC data with dijet cross sections measured at HERA, we extend the range to test the predicted running of the strong coupling towards smaller scales. Our results exhibit excellent agreement with predictions based on the renormalization group equation of QCD. This study represents the a very comprehensive test of the asymptotic behaviour of QCD, spanning over three orders of magnitude in energy scale from 7GeV up to 7TeV. (work based on arXiv:2412.21165)

Speaker: Claire Gwenlan (University of Oxford (GB))

QCD@LHC25-alphas-Gwenlan.pdf

09:00 → 10:30 Perturbative and resummed predictions, parton showers and event generators for LHC and EIC: Parallel 1A

09:00 Studies on event shape variables with ATLAS and CMS

Speaker: Alex Sopio (The University of Edinburgh (GB))

20250909_qcd2025_jss_atlas_cms.pdf

09:00 ZOOM ROOM

https://cern.zoom.us/j/68425865737?pwd=TYFg23pw7d4ALZo8vlq4NEIgFC7w5L.1

09:30 Automated calculation of soft functions for non-global observables

Collider observables can broadly be grouped into two classes: global observables, like e.g. many event shapes, and non-global observables, whose defining property is that they are sensitive to radiation only in part of the phase space. Non-globality gives rise to a special type of large logarithm, whose resummation is more involved than resummation in the global case. A framework to resum these logarithms has been developed based on Soft-Collinear Effective Theory, which involves intricate factorisation theorems with ingredient functions of arbitrary final state hard multiplicities.

In this talk I will present some progress towards automating the calculation of soft functions for non-global observables to second order in the strong coupling constant. I will focus in particular on subtleties arising from the two-emission contribution with one emission inside and one out of the measurement region, and on extensions to the uncorrelated emission case.

Speaker: Rudi Rahn (University of Vienna)

QCDLHC25_Rahn.pdf

10:00 NNLO Subtraction based on scalar QCD and pure splitting functions

In this talk, I will present a novel decomposition of QCD splitting functions, developed systematically up to second order in the strong coupling constant. The key idea is to express the splitting functions as a sum of two distinct components: scalar dipole radiator functions and pure remainder terms. Unlike traditional methods, this framework avoids relying on soft or collinear approximations, offering a more general and robust structure. This decomposition not only provides deeper insight into the analytic structure of QCD radiation but also naturally works in practical applications. I will also present first results illustrating how this approach can be used to build a subtraction scheme.

Speaker: Max Knobbe (Fermilab)

qcd-at-lhc-2025-knobbe.pdf

10:30 → 11:00 Coffee Break

11:00 → 12:30 Heavy Quarks (including top and flavour physics): Parallel 1B

Conveners: Fabrizio Grosa (CERN), Philipp Böer

11:00 Observation of a family of all-charm tetraquark states

We present a comprehensive study of near-threshold structures in the J/\psi J/\psi mass spectrum using the fully reconstructed J/\psi J/\psi \rightarrow 4\mu final state, based on proton-proton collision data at \sqrt{s} = 13 and 13.6 TeV collected by the CMS experiment. With approximately four times more J/\psi pair candidates compared to the previous Run 2 dataset, the combined data sample enables a significantly enhanced sensitivity to rare structures. In the mass range between 6 and 8 GeV, three peaks are observed with significances well above 5σ, consistent with the previously reported tetraquark candidates X(6600), X(6900), and X(7100). Two pronounced dips, also exceeding 5σ in significance, are identified between the peaks, highlighting the presence of strong interference effects. A complementary search in the J/\psi \psi(2S) \rightarrow 4\mu final state reveals a consistent two-peak structure corresponding to the X(6900) and X(7100), with measured masses and widths compatible within uncertainties. To further investigate the nature of the observed states, a spin-parity analysis is performed using a matrix-element-based approach, testing multiple J^P hypotheses. The results favor a J^P = 2^+ assignment, offering new insights into the internal dynamics of these exotic resonances. This analysis, based on the Run 2 data, provides the most detailed picture to date of the fully-charm tetraquark landscape.

Speaker: Kai Yi (Nanjing Normal University (CN))

QCDatLHC2025.pdf

11:30 Probing spin correlations, entanglement, and Bell nonlocality in bottom quark pairs at the LHC

While spin correlations and spin entanglement have been measured for top quarks at the LHC, they remain unexplored for other quark flavors. We propose analysis strategies for measuring spin correlations, entanglement, and Bell nonlocality in $b \bar b$ samples using the partial preservation of the spin information in $\Lambda_b$ baryons from bottom quark fragmentation. We find that certain measurements are feasible with existing datasets, while others will become possible at the HL-LHC. The proposed measurements will also provide new information on the currently poorly known polarized fragmentation functions.

Speaker: Yevgeny Kats (Ben-Gurion University)

spin-correlations-QCD-LHC.pdf

12:00 Unresolved Questions in Cold Nuclear Matter and Future Strategies

This contribution presents a review of cold nuclear matter (CNM) effects [1] in hadron-nucleus collisions, with a focus on hard probes such as Drell–Yan pairs, heavy flavor, and quarkonium production. By examining yield modifications as functions of transverse momentum and rapidity, we aim to disentangle the underlying QCD mechanisms — including gluon saturation, nuclear PDFs, and parton energy loss. The analysis explores whether suppression patterns reflect universal features or point to process-dependent. We also discuss how future measurements at the Electron-Ion Collider (EIC) can provide decisive insights, outlining strategies to separate initial- and final-state effects. This overview offers a roadmap for interpreting upcoming nuclear data and deepening our understanding of QCD in nuclear environments.

[1] F. Arleo, P. Caucal, A. Deshpande, J. M. Durham, G. M. Innocenti, J. Jalilian‑Marian, A. Kusina, M. X. Liu, Y. Mehtar‑Tani, C. J. Naïm, H. Paukkunen, S. Platchkov, F. Salazar, I. Vitev, and R. Vogt, “Nuclear Cold QCD: Review and Future Strategy,” arXiv, Jun. 20, 2025. [Online]. Available: arXiv:2506.17454

Speaker: Charles Joseph Naim

QCD@LHC_CNM.pdf

11:00 → 12:30 Parton distribution functions: Parallel 1B

11:00 News from MSHT

We will discuss several key updates to the MSHT PDF family of fits, with focus on approximate N3LO; including updates on closure tests and the evaluation of errors on errors, the combination of aN3LO QCD PDFs with QED effects, the first determination of the strong coupling constant at aN3LO, and further updates based on new theoretical information available at N3LO including more precise splitting functions and newly determined transition matrix elements.

Speaker: Dr Lucian Alexander Harland-Lang (University College London)

lhl_QCD@LHC25_comp.pdf

11:20 Progress in the NNPDF global analysis framework

We present a progress report on the NNPDF framework for unpolarised PDF determination. We review our recent results of NNPDFs based on aN3LO calculations and with QED corrections, its statistical combination with MSHT20, and the implications for Higgs cross-sections. We discuss a determination of the strong coupling based on a global aN3LO PDF fit, which for the first time is based on a methodology based on closure tests. We summarise progress towards a new NNPDF release in terms of experimental data, theory calculations (with NNLO fast grids for all processes), and fitting methodology.

Speaker: Felix Hekhorn (University of Jyväskylä)

talk.pdf

11:40 Update on the CTEQ-TEA global PDF analysis

I review recent results on the precision NNLO and partial N3LO analysis of parton distribution functions by the CTEQ-TEA group.

Speaker: Prof. Pavel Nadolsky (Michigan State University)

p908.pdf

12:00 Update of ABMPtt fit

We discuss an update of the ABMPtt simultaneous fit of proton PDFs, heavy-quark masses and $\alpha_S(M_Z)$ incorporating a photon component in the proton. We study the impact of higher-twist effects in DIS, also relevant for future analyses at EIC, on $\alpha_S(M_Z)$ by considering variants of the fit including and not including various collider data sets. We discuss the compatibility of different data sets among each other and the compatibility of the results with those of other modern global fits. We present cross sections for benchmark processes at the LHC, such as single top production.

Speaker: Oleksandr Zenaiev (Hamburg University)

Zenaiev-QCDLHC2025-abmp.pdf

11:00 → 12:30 Perturbative and resummed predictions, parton showers and event generators for LHC and EIC: Parallel 1B

11:00 Studies on jet substructure at ATLAS and CMS

Speaker: Baris Tuncay (University of Oxford (GB))

BarisTuncay_QCDatLHC2025_Fin.pdf

11:30 Small radius inclusive jet production at the LHC

Precision studies of jets and their substructure at the LHC require a robust theoretical description for anti-$k_T$ jet production. For small-radius jets, the cross section can be factorized into parton distribution functions, a hard function, and a jet function that encodes the jet clustering effects. We present the two-loop calculation of this jet function and uncover previously missing logarithms in the standard DGLAP factorization. Building on the recent understanding of energy correlators, we propose a corrected factorization formula and perform the next-to-next-to-leading logarithmic resummation for small-radius jet production at the LHC. This result shows good agreement with the CMS measurements. Our framework extends naturally to a broad class of jet substructure observables and other collider experiments, offering the potential for more precise QCD measurements.

Speaker: Xiaoyuan Zhang

QCDLHC2025_XYZ.pdf

12:00 The quark jet function for kT-like variables in NNLO QCD

Jets are collimated bunches of hadrons that represent the fingerprints of the partons produced by the hard scattering processes. The precise description of jets requires the definition of observables that can capture the dynamics of final-state energy flow. We consider a class of transverse-momentum-like observables that resolve the transition between configurations with $n$ and $n+1$ jets in multi-jet processes. We develop a semi-numerical method to compute the corresponding quark jet function at NNLO in perturbative QCD. Explicit results are provided for observables in both the E-scheme and the WTA recombination scheme. The rapidity divergences are addressed using a regularization method based on momentum fractions defined w.r.t. a time-like reference vector. The jet function can be used as a building block for the computations of jet cross-sections at colliders, using a slicing method based on a $k_T$-like resolution variable. We demonstrate an application of our results by computing NNLO jet cross-sections in leptonic collisions using a slicing scheme that incorporates our jet function.

Speaker: Flavio Guadagni

FlavioGuadagni.pdf

12:30 → 14:00 Lunch Break

14:00 → 15:30 Perturbative and resummed predictions, parton showers and event generators for LHC and EIC: Parallel 1C

14:00 Studying high-order QCD operators with resolved energy-energy correlators at the CMS experiment

Speaker: Simon Rothman (Massachusetts Inst. of Technology (US))

QCD@LHC 2025-3.pdf

14:30 Analytic computation of two-loop di-photon and di-jet amplitudes with a massive quark loop

In this talk, I will present recent progress on the analytic computation of two-loop scattering amplitudes for the production of two photons or gluons in parton-parton collisions involving a heavy top quark. These calculations require evaluating a set of master integrals that feature elliptic geometries—structures which have traditionally limited the analysis to semi-numerical methods. By leveraging recent developments in the theory of canonical differential equations, I will demonstrate how all relevant master integrals can be computed analytically in terms of iterated integrals. These integrals involve both well-known polylogarithmic and elliptic differential forms. Importantly, I will argue that the resulting function space of iterated integrals possesses desirable structural properties, notably the linear independence of all appearing functions. This independence facilitates significant simplification of the final analytic expressions for the scattering amplitudes. Moreover, by constructing series representations—first for the master integrals and subsequently for the full amplitudes—we achieve fast and highly accurate numerical evaluations across the relevant parameter space.

Speaker: Christoph Nega (TUM)

QCD@LHC.pdf

15:00 Three-Loop QCD Corrections to the Helicity Amplitudes for Higgs-boson-plus-jet production

An additional final state jet is a requirement for any observable that depend on the Higgs boson having non-vanishing transverse momentum and enables to broaden the set of observables of the Higgs boson physics. To improve the theoretical description of the Higgs-boson-plus-jet production, we derive the three-loop QCD corrections to the helicity amplitudes for the process $H \rightarrow ggg$ and $H \rightarrow q \bar{q} g$ in the heavy top limit and leading color approximation. The results are represented in terms of multiple polylogarithms.

Speaker: Xin Guan

20250906 QCDLHC2025 XinGuan.pdf

14:00 → 15:30 Soft interactions, non-perturbative QCD: Parallel 1A

14:00 Precision QCD Measurements Using Archived ALEPH Data

High-energy $e^{+}e^{-}$ data are essential for a global understanding of particle physics. Despite decades since the end of the Large Electron-Positron Collider (LEP), its data continue to play a central role in the precise study of perturbative and non-perturbative QCD. In this talk we present high precision and resolution measurements of energy-energy correlator (EEC) and thrust at $\sqrt{s} = 91.2$ GeV, as well as two-particle correlations at center-of-mass energies up to $\sqrt{s} = 209\,\mathrm{GeV}$ using archived ALEPH data. The measured EEC is corrected for detector effects and compared to theoretical predictions with Next-To-Next-To-Next-To Leading Log ($N^3LL$) resummation in the collinear limit and Next-To-Next-To-Next-To-Next-To Leading Log ($N^4LL$) in the Sudakov limit. Thrust is unfolded using an ML-based method called $\text{UniFold}$, and the result is provided unbinned for the first time, allowing for downstream fully differential and variable binning studies. The measurement of two-particle angular correlations leverages a new analysis strategy focusing on enhancing the contribution from $W^+W^-$ processes, provides new insights into the emergence of long-range correlations in small systems, and offers important context for similar phenomena observed in proton-proton, proton-nucleus, and nucleus-nucleus collisions.

Speaker: Hannah Bossi (Massachusetts Inst. of Technology (US))

HBossi_QCDatLHC2025.pdf

15:00 Hadronization Studies at LHCb

LHCb is a detector designed to study the dynamics of particles produced at forward rapidities (2 < η < 5). This rapidity coverage is particularly well suited for investigating non-perturbative processes, such as the hadronization of light and heavy-flavored quarks. The latter is of special interest due to the distinct radiation patterns and hadronization timescales of heavy quarks compared to light quarks. In this talk, we will briefly review the experimental conditions at LHCb to provide context for the measurements, and then delve more deeply into key results in the study of non-perturbative QCD and soft interactions at LHCb.

Speaker: Esteban Felipe Molina Cardenas (University of Michigan (US))

Hadronization Studies at LHCb (definitive).pdf

14:00 → 15:30 Higgs, electroweak, BSM physics: Parallel 1A

Conveners: Clara Lavinia Del Pio (Brookhaven National Lab), Gaetano Barone (Brown University), Hannah Arnold (Stony Brook University)

14:00 Measurements of multi-boson and rare electroweak processes at ATLAS and CMS (incl. VBS and polarization measurements)

Speaker: Jonny Allen (The University of Manchester)

Measurements of multi-boson and rare electroweak processes at ATLAS and CMS.pdf

14:22 Polarized boson pairs at NLO in the SMEFT

We present a computation of inclusive diboson production in the $W^{\pm} Z$ channel at the Large Hadron Collider (LHC), incorporating leptonic decays of the gauge bosons and considering intermediate gauge bosons with definite polarization states. The analysis includes contributions from the Standard Model effective field theory (SMEFT) and is carried out at next-to-leading order (NLO) accuracy in QCD, matched to a parton-shower simulation.
Our implementation allows for the selection of specific helicity configurations, both in the Standard Model and in the presence of dimension-six operators inducing anomalous triple gauge boson couplings.

Speaker: Jakob Linder (Max-Planck Institut for physics)

Jakob_Linder_QCDatLHC_2025_handout.pdf

Jakob_Linder_QCDatLHC_2025.pdf

14:44 Quantum properties of H → V V ∗ : precise predictions in the SM and sensitivity to new physics

We study the quantum properties of the Higgs-boson decays into four fermions via two vector bosons (H→VV^∗→4f). In particular, we focus on the case of two different-flavour lepton pairs (H→ZZ^∗→μ+μ−e+e−). We compute the quantum-information observables for the corresponding two-qutrit system (ZZ) at next-to-leading order electroweak (NLO EW) accuracy in the SM. We find that NLO EW corrections lead to giant (order 1) effects in some specific cases and significantly alter the extraction of the observables quantifying the quantum correlations. We identify the observables that are robust and can be used to extract reliable information. Finally we discuss possible new physics (NP) effects, parametrised via an effective-field-theory approach. We show how quantum observables can increase the sensitivity to NP also for the process considered in this study.

Speaker: Priyanka Lamba

QCD@LHC_PLamba.pdf

15:05 Measurements of the Higgs-boson properties (mass, CP, width) at ATLAS and CMS

Speaker: Alessandro Tarabini (ETH Zurich (CH))

QCD@LHC_Tarabini.pdf

15:30 → 16:00 Coffee Break

16:00 → 17:00 Perturbative and resummed predictions, parton showers and event generators for LHC and EIC: Parallel 1D

16:00 Precision Event Shape Analysis for DIS at the HERA and EIC

In this talk, I present a state-of-the-art analysis of the 1-jettiness event shape using Soft-Collinear Effective Theory (SCET). This work achieves N$^3$LL + $\mathcal{O}(\alpha_s)$ acccuracy with full fixed-order matching and inclusion of nonperturbative corrections. It stands among the most precise event-shape predictions in DIS to date and enables competitive extractions of both the strong coupling constant $\alpha_s$ and the universal power correction parameter $\Omega_1$. The formalism is directly applicable to both HERA and upcoming EIC measurements.

Speaker: June-Haak Ee (Los Alamos National Laboratory)

JHEE-QCD@LHC_pdf.pdf

JHEE-QCD@LHC.pptx

16:30 Event generation at MEPS@NLO accuracy in neutral and charged current DIS at the EIC

In this talk we will discuss the first hadron-level predictions at MEPS@NLO precision for both neutral and charged current DIS at the EIC and the first application of the MEPS@NLO technique to charged current DIS in general. In recent years, lepton-hadron scattering has garnered more attention again due to the upcoming
planned for the Electron-Ion Collider (EIC) at Brookhaven National Laboratory. Most previous Monte Carlo event generator based studies of inclusive DIS phenomenology for the EIC have relied on LO calculations, or parton showers matched to NLO for the lowest multiplicity DIS process. Here, we present a study of precision DIS phenomenology at the EIC using the SHERPA event
generator. Specifically, we employ its automated matching and merging capabilities to produce the most
precise, fully exclusive hadron-level predictions to date. We analyze both traditional DIS observables and
hadronic event shapes, including 1-jettiness, jet multiplicities, and leading-jet transverse momentum. To
assess theoretical uncertainties, we perform independent evaluations of perturbative and non-perturbative
effects, identifying limitations in theoretical predictions relevant to EIC analyses.

Speakers: Daniel Reichelt, Federico Silvetti, Peter Meinzinger (Zürich University)

QCD@LHC25_Silvetti.pdf

16:00 → 17:30 Soft interactions, non-perturbative QCD: Parallel 1B

16:00 Exclusive lepton production and soft QCD challenges for tau g–2

Exclusive electron and muon pair production ($\gamma\gamma\to ee/\mu\mu$) is traditionally measured as an LHC standard candle to probe the enigmatic soft QCD physics of proton breakup. Until recently, exclusive tau-lepton pair production ($\gamma\gamma\to \tau\tau$) was overlooked at the LHC. However, its potential sensitivity to the mysterious tau anomalous magnetic moment ($g-2$) has triggered a renaissance of theoretical and experimental activity. Precision is limited by systematic uncertainties dominated by non-perturbative physics in background and signal: hadronic-jet identification, underlying event, pileup modelling, elastic and inelastic photon fluxes, proton breakup from dissociation and rescattering. This highlights the importance of designing measurements to constrain such soft QCD effects underpinning the novel LHC tau $g–2$ program. Based on Beresford, Clawson, Liu [PRD 110 (2024) 092016].

Speaker: Jesse Liu (New York University)

QCD@LHC-9Sep2025-JL.pdf

16:30 Study of soft QCD phenomena and double parton interaction in ATLAS

Despite the success of perturbative QCD predictions at the high-energy regime, QCD itself remains mysterious at its nominal scale (QCD scale). The LHC offers rich opportunities to probe the core of QCD related questions, by studying minibias events, double parton interactions, small-x and diffractive processes, as well as correlations in hadronization processes. This talk will summarize recent achievements from ATLAS on this topic.

Speaker: Camila Pazos (Tufts University (US))

soft-qcd-QCDatLHC25.pdf

17:00 Transverse momentum dependent structure from topological QCD vacuum

We introduce a general framework based on topologically active configurations, known as instantons, in the QCD vacuum to evaluate the non-perturbative transverse partonic structure of hadrons. Specifically, we derive the transverse-momentum-dependent parton distribution functions (TMDPDFs) for the pion, kaon, and rho meson, along with the Collins-Soper (CS) kernel, which governs the rapidity evolution of TMDPDFs. Our results offer a tomographic view of the pion and kaon parton structure in both the parton fraction $x$ and transverse space $b$. The derived CS kernel, when supplemented with perturbative contributions, aligns well with recent lattice QCD results and phenomenological fits. Additionally, we find that the CS kernel exhibits a logarithmic dependence on large quark transverse separation $b$, providing a crucial constraint for its phenomenological parametrization. Lastly, our framework allows direct comparison with lattice calculations in Euclidean signature, offering a novel approach to evaluating the soft function and extracting the CS kernel via analytical continuation.

Speaker: Wei-yang Liu (Stony Brook University)

Transverse_momentum_dependent_structure_from_topological_QCD_vacuum__QCD_LHC_2025_ (1).pdf

16:00 → 17:45 Higgs, electroweak, BSM physics: Parallel 1B

Conveners: Clara Lavinia Del Pio (Brookhaven National Lab), Gaetano Barone (Brown University), Hannah Arnold (Stony Brook University)

16:00 Electroweak precision measurements at ATLAS and CMS (incl. Drell-Yann and W/Z mass measurements)

Speaker: Takuya Nobe (University of Tokyo (JP))

QCD@LHC.pdf

16:22 Towards two-loop EW corrections at NLL in OpenLoops

At energies above the Electroweak (EW) scale, higher-order EW corrections exhibit a logarithmic enhancement which is driven by the ratio of the typical scattering energy to the gauge-boson mass. At next-to-leading order (NLO) these corrections lead to factors amounting to several tens of percent in tails of kinematic distributions of crucial LHC processes, and still contribute a few percent at next-to-next-to-leading order (NNLO). As such, their inclusion is essential to reduce theoretical uncertainties arising from missing higher-order corrections.
In this talk, I will review the key features of the algorithm implemented in OpenLoops (OL) for calculating one-loop EW corrections in the logarithmic Sudakov approximation, namely at next-to-leading logarithmic (NLL) accuracy, and present the status towards its extension to the two-loop level. This approximation efficiently implements the Denner-Pozzorini algorithm using an effective vertex approach, enabling to reproduce the full one- and two-loop results with percent-level accuracy while preserving tree-level computational complexity.

Speaker: Lorenzo Mai (University of Genova)

LM_QCD@LHC 2025.pdf

16:44 Higgs-boson cross-section measurements (fiducial, STXS,..) and their combinations at ATLAS and CMS (incl. kappa interpretation))

Speaker: Marta Lanzac Berrocal (Univ. of Valencia and CSIC (ES))

QCD@LHC2025.pdf

17:06 RVVxV: Interference contributions to inclusive Higgs boson and Drell-Yan production at N4LO in QCD

We present partonic contributions to the inclusive gluon-fusion Higgs boson and Drell-Yan production cross sections at Hadron colliders at next-to-next-to-next-to-next-to leading order (N4LO). Specifically, we compute contributions due to the interference of one-loop amplitudes with two-loop amplitudes with three QCD partons and the Higgs boson or a virtual photon. Our result is in the form of a Laurent expansion in the dimensional regulator ϵ, the coefficients of which are analytic functions in the ratio of the Higgs boson or virtual photon mass to the partonic center of mass energy. Furthermore, we introduce and deploy a new package implemented in Mathematica, CIFAR ("Color Invariant Feynman Amplitude Reducer"), to express color factors in terms of general Casimir invariants of simple compact Lie algebras.

Speaker: Adi Suresh (Stanford University, SLAC)

QCD@LHC2025_AdiSuresh.pdf

17:28 EFT measurements and interpretations for Higgs & EWK processes at ATLAS and CMS

Speaker: Darien Wood (Northeastern University (US))

QCD2025_EFT_Wood_v3.pdf

QCD2025_EFT_Wood_v3.pptx

Wednesday 10 September

09:00 → 10:30 Plenary: Plenary 5

Conveners: Prof. Christine Aidala, Christine Aidala (University of Michigan (US))

09:00 Perturbative computations for PDFs from the lattice

Parton Distribution Functions (PDFs) are crucial non-perturbative inputs for collider physics but cannot be calculated directly in lattice QCD. Modern approaches like Large-Momentum Effective Theory (LaMET) bridge this gap by computing lattice-accessible spatial correlators — known as quasi- and pseudo-PDFs — which are related to light-cone PDFs via a perturbative matching procedure. The choice of matching/renormalization scheme and the precision of the matching calculation are key theoretical challenges for the entire program.

In this work, we present a complete one-loop calculation of the matching kernels for both quark and gluon distributions, required to connect these lattice quantities to light-cone PDFs in the standard $\overline{\text{MS}}$ scheme. We provide results for both the quasi- and pseudo-PDF approaches. This calculation provides the essential continuum component for matching results from various practical lattice renormalization schemes to the one used in phenomenology. A novel aspect of our work is the presentation of the gluon matching kernels in a general tensor decomposition, allowing for the construction of results for arbitrary operator choices without recalculation. We establish the robustness of our results through calculations in multiple gauges and address key theoretical subtleties in the required Fourier transforms. This work clarifies the matching procedure and provides a comprehensive framework for improving the precision of PDF extractions from current and future lattice QCD simulations.

Speaker: Tobias Neumann (Southern Methodist University)

Neumann_Tobias.pdf

09:30 Parton showers and event generators

Speakers: Daniel Reichelt, Daniel Reichelt (CERN)

QCDatLHC_2025_DReichelt.pdf

10:00 Energy correlators at the LHC and the EIC

Speaker: Ian Moult

IanMoult_QCDLHC_2025.pdf

10:30 → 11:00 Conference Photo / Coffee Break

11:00 → 13:00 Plenary: Plenary 6

Convener: Gaetano Barone (Brown University)

11:00 Single Boson and multi boson prod at the LHC

Speaker: Saptaparna Bhattacharya (Southern Methodist University (US))

QCDATLHC_2025.pdf

11:30 The heavy ion program at RHIC with the sPHENIX experiment

Speaker: Hanpu Jiang (Columbia University)

sPHENIX QCD@LHC.pdf

12:00 Heavy Ions results from LHC

Speaker: Friederike Bock (Oak Ridge National Laboratory - (US))

QCDLHC25_HIAtLHC.pdf

12:30 Extractions of the strong coupling from LHC measurements

Speaker: Matt LeBlanc (Brown University (US))

20250908_MLB_QCDatLHC_AlphaS.key

20250908_MLB_QCDatLHC_AlphaS.pdf

13:00 → 19:00 Free: Free time

Thursday 11 September

09:00 → 10:30 Polarized deep-inelastic physics: Parallel 2A

09:00 Polarized measurements with the EPIC detector at the EIC

The ePIC detector at the upcoming Electron-Ion Collider will open an unprecedented window into the inner workings of protons and nuclei. Optimized for polarized deep inelastic scattering, semi-inclusive and exclusive processes, and diffractive channels, ePIC will achieve unmatched precision in these measurements. It will enable detailed studies of the origin of nucleon spin and the three-dimensional structure of matter. Through high-luminosity collisions of polarized electrons with polarized protons, ePIC will map the contributions of quark and gluon spins, orbital angular momentum, and their correlations to the total nucleon spin. The detector will also reconstruct multidimensional parton distributions in both momentum and position space, using transverse-momentum-dependent parton distributions (TMDs) and generalized parton distributions (GPDs). These measurements will provide critical insight into QCD dynamics, confinement, and the internal landscape of hadronic matter.

Speaker: Norbert Novitzky (Oak Ridge National Laboratory - (US))

ePICpolarization_Novitzky.pdf

09:30 NNPDFpol2.0

We discuss the latest release of polarized PDFs from the NNPDF collaboration and highlight the recent progress in their determination. Specifically, first, we include most currently available data at polarized colliders; second, we investigate the improved hyper-optimization strategy of our neural network methodologies for the extraction of PDF; third, we use an improved theory framework, which accounts for next-to-next-to-leading order corrections, heavy quark mass effects, and estimating missing higher order uncertainties.

Speaker: Felix Hekhorn (University of Jyväskylä)

talk.pdf

10:00 Updates from JAM at high x and the reco of d2 and polarized HT effects.

I will discuss recent work on d2.

Speaker: Nobuo Sato

talk

talk

09:00 → 10:30 Soft interactions, non-perturbative QCD: Parallel 2A

09:00 Entropy Scaling in Proton-Proton Collisions: A Quantum Information Perspective

In this talk, we present results from analyzing pseudorapidity-binned charged-particle multiplicity distributions from proton-proton collisions at center-of-mass energies from 0.9 to 13 TeV, using data from the ATLAS experiment. For each multiplicity distribution, we compute the associated Shannon entropy to quantify the complexity of the final state. Surprisingly, we find that the entropy remains approximately constant across a wide range of energies and multiplicities, even as the total number of charged particles increases. To better understand this behavior, we define a quantity called the “entropy scaling coefficient,” which systematically decreases with multiplicity. Our results suggest a form of universal information structure in high-energy QCD final states, offering a complementary perspective to standard analyses in collider phenomenology.

Speaker: Mira Varma (Yale University (US))

Mira_Varma_LHC@QCD_2025.pdf

10:00 Entanglement as a probe of hadronization

In this talk, we present our extension of the concept of maximal quantum entanglement from proton structure to jet fragmentation in proton-proton collisions, establishing a connection between jet fragmentation functions and charged hadron multiplicity [1]. This relationship is tested using ATLAS data from the Large Hadron Collider, showing excellent agreement. As the first study to apply quantum entanglement concepts to hadronization within jets, our results provide new insights into the quantum aspects of hadronization and the transition between perturbative and non-perturbative QCD, deepening our understanding of confined nuclear matter.

[1] J. Datta, A. Deshpande, D. E. Kharzeev, C. J. Naïm, and Z. Tu, “Entanglement as a probe of hadronization,” arXiv, no. 2410.22331, Oct. 2024.

Speaker: Charles Joseph Naim

QCD@LHC_Entropy.pdf

09:00 → 10:30 Higgs, electroweak, BSM physics: Parallel 2A

Conveners: Clara Lavinia Del Pio (Brookhaven National Lab), Gaetano Barone (Brown University), Hannah Arnold (Stony Brook University)

09:00 Non-resonant HH searches and H+HH combinations by ATLAS and CMS

Speaker: Lucrezia Boccardo (INFN e Universita Genova (IT))

Boccardo_QCDLHC.pdf

09:22 Do large QCD corrections survive parton showers in di-Higgs decays?

While significant effort has been devoted to precision calculations of di-Higgs production, the subsequent decays have received comparatively less attention. Recent studies have shown that fixed-order QCD corrections to fiducial di-Higgs decay rates can be sizable. In this talk, I demonstrate that these large corrections arise predominantly from soft and collinear QCD radiation and can therefore be efficiently addressed by parton showers.

Speaker: Duarte Fontes

Presentation.pdf

09:44 Triple Higgs Boson Production at the LHC in Extended Scalar Sectors

Multi-Higgs boson production processes can provide essential insights into the scalar sector of the Standard Model (SM). Exploring the production of three Higgs bosons is primarily motivated by the unique opportunity it offers to measure the Higgs quartic self-coupling. Although observing triple Higgs production within the SM presents significant experimental challenges at the LHC, due to its exceptionally small cross section, the process becomes potentially observable in scenarios involving extended scalar sectors. In this talk, we will review the key theoretical and phenomenological aspects of triple Higgs boson production in extended scalar sectors at hadron colliders, focusing on the scenario with two additional heavy scalars.

Speaker: Dr Andreas Papaefstathiou (Kennesaw State University, GA, USA)

QCDatLHC_Sep2025.pdf

10:06 Resonant HH and HHH searches at ATLAS and CMS

Speaker: Emanuela Barberis (Northeastern University (US))

QCD2025_barberis_v2_ws.pdf

10:30 → 11:00 Coffee Break

11:00 → 12:30 Polarized deep-inelastic physics: Parallel 2B

11:00 UVA NMR System of the SpinQuest Polarized Target System

Polarized targets are essential tools in probing nucleon spin structure within high-energy and nuclear physics experiments. The SpinQuest polarized target system at Fermilab includes key components such as a cryogenic evaporation refrigerator for high-power cooling at 1 K, a roots pump stack with 17000 m3/hour of pumping capacity, a microwave generator, and NMR system. The polarization is achieved using the DNP (Dynamic Nuclear Polarization) technique with 5T magnetic field and an extended interaction oscillator (EIO) microwave tube capable of producing 140 GHz. An ammonia target is used for both proton (spin 1/2) and deuteron (spin 1) as well as neutron (spin 1/2) polarization. A Q meter based nuclear magnetic resonances (NMR) system is utilized to measure the polarization over the course of the experiment. The SpinQuest polarized target system has achieved well over 90% polarization with solid NH3 and has completed a set of target commissioning runs and taken some production data. An analysis of the target polarization under high proton intensity will be presented in this talk.

Speaker: Nuwan Chaminda Gunawardhana Waduge (University of Virginia (US))

11:22 TMDs: Twist-2 Matching, Observables and High-Energy Evolution

We present recent progress in precision TMD physics, focusing on three key developments. First, we provide the N3LO twist-2 matching for polarized TMDs, along with the complete set of N3LO polarized DGLAP evolution kernels for quark (gluon) helicity and quark transversity distributions. Second, we achieve N3LL accuracy in predictions for the SIDIS $q_T$ spectrum, the lepton-hadron transverse momentum imbalance, and semi-inclusive Transverse Energy–Energy Correlators (TEEC). Finally, we introduce an exponential regulator in SCET$_G$ and Lipatov’s Reggeon Field Theory, thereby enabling precise studies of quark–gluon reggeization, the dynamics of small-$x$ TMDs, and TMD factorization violation.

Speaker: Yu Jiao Zhu (Max-Planck Institute for Physics)

Zhu_TMDs.pdf

11:44 Lattice QCD Benchmark of Proton Helicity and Flavor-Dependent Unpolarized TMDPDFs at Physical Quark Masses

We present recent lattice QCD results on transverse momentum dependent distributions (TMDs) using boosted hadron correlators in the Coulomb gauge. This method avoids power divergences from Wilson lines and improves access to large momenta and long-range separations. We compute isovector helicity and flavor-dependent unpolarized TMDPDFs of the proton at physical quark masses, using domain-wall fermions and Coulomb-gauge-fixed bilocal correlators. The results reveal mild flavor dependence and consistent helicity-to-unpolarized ratios, with direct comparison to global fits. We also demonstrate the method’s effectiveness for calculating unpolarized and polarized proton collinear PDFs, showing consistency with global fits. These results highlight the Coulomb-gauge boosted-field framework as a unified tool for studying nucleon structure on the lattice.

Speaker: Xiang Gao

QCDatLHC_XG.pdf

12:06 Feasibility of probing parton orbital angular momentum through elastic dijet production in electron-proton collisions

Elastic dijet production in electron-proton collisions is one of the main proposed probes of the quark and gluon orbital angular momentum (OAM) distributions. In particular, the azimuthal angular correlations amongst the jets, outgoing proton, and outgoing electron provide access to the OAM distributions. At small $x$, this access is quantified through the first impact-parameter moments of the polarized dipole amplitudes, which have been shown to be directly related to the OAM distributions. In this study, we assess the feasibility of extracting these moment amplitudes through azimuthal correlations in the double spin asymmetry of elastic dijet production at the future Electron-Ion Collider. We identify the kinematic regimes with enhanced sensitivity and discuss both the opportunities and limitations associated with this process, including constraints from the magnitude of the cross section and experimental resolutions.

Speaker: Brandon Manley

manley_dijets.pdf

11:00 → 12:30 Soft interactions, non-perturbative QCD: Parallel 2B

11:00 Measurement of Hadronic Event Shape, Energy-Energy Correlator, and Two-Particle Correlation with DELPHI Open Data

Recent theoretical developments have renewed interest in measurements of event shape variables in $e^{+}e^{-}$ collisions. We present a measurement of thrust, energy-energy correlator, and two-particle angular correlations of charged particles in $e^+e^-$ collisions at center-of-mass energies up to $\sqrt{s} = 209\,\mathrm{GeV}$, using newly released open data access from the DELPHI experiment at LEP-I and -II. The thrust and energy-energy correlator, measured with unprecedented resolution and precision, are compared with various MC and analytic predictions. These analyses, leveraging DELPHI’s unique detector geometry and reconstruction capabilities, complement previous DELPHI and recent ALEPH re-analysis results, providing valuable inputs for precision tests of QCD in the relatively unexplored Sudakov limit. In addition, this study explores potential collective behavior in $e^+e^-$ collisions by analyzing angular correlations over a wide range of pseudo-rapidities and full azimuth, as a function of event charged-particle multiplicity with respect to thrust. These measurements expand the current measurement landscape with LEP data and set a benchmark for future studies in $e^+e^-$ collisions.

Speaker: Jingyu Zhang (Vanderbilt University (US))

2509011-QCD@LHC.pdf

11:30 Hadron mass structure emerged from QCD vacuum: EMT and trace form factor

In the QCD vacuum, the hadron structure receive contributions from the topologically active configuration, known as instantons. We present a general framework to explore the impact of instantons on hadron form factors. The results of the gravitational and trace form factor, and its related Ji’s mass sum rules at medium resolution, shows consistency with recent lattice results when evolved to higher resolution, providing insight into the essential role of instantons in shaping the gluonic and mechanical structure of hadrons.

Speakers: Christian Weiss, Edward Shuryak, Ismail Zahed, Wei-yang Liu (Stony Brook University)

Hadron_mass_structure__EMT_and_trace_form_factor__QCD_LHC_2025_.pdf

12:00 Flow and Correlation Measurements in Large and Small Systems with ATLAS

Speaker: Yuhan Guo (Columbia University (US))

atlas-flow-corr-qcd-at-lhc-yuhan-guo-v2.pdf

11:00 → 12:40 Higgs, electroweak, BSM physics: Parallel 2B

Conveners: Clara Lavinia Del Pio (Brookhaven National Lab), Gaetano Barone (Brown University), Hannah Arnold (Stony Brook University)

11:00 Measurements of rare Higgs-boson processes at ATLAS and CMS (excl. H→cc)

Speaker: Arianna Gemma Garcia Caffaro (Yale University (US))

Rare_Higgs_Processes_transitions.pdf

11:22 GraviWeak and Spontaneous symmetry breaking

The maximal parity violation of electroweak physics has thus far been successfully described, but not yet explained in terms of more fundamental structures. Graviweak unification proposes to address this question by unifying gravity in its self-dual formulation with the weak interactions via their parallel chiral structures. In this work we showcase a graviweak model in which spontaneous symmetry breaking plays a role. This is achieved using a Higgs field and its potential inside a parity-invariant theory which splits into the gravitational and weak interactions and gives rise to parity violation in the weak sector. We discuss generalizations which incorporate non-minimal couplings between the Riemann curvature and the gauge field strengths. Finally we discuss the experimental ramifications of our model regarding gravitational parity violation and non-minimal coupling between gravitons and weak gauge bosons.

Speaker: Max Pezzelle

PezzelleGraviweakSlides.pdf

11:44 Measurements of Higgs-quark interactions at ATLAS and CMS

Speaker: Beatriz Ribeiro Lopes (CERN)

QCD@LHC Higgs talk.pdf

12:06 Beyond the Standard Model in the Higgs sector at ATLAS and CMS

Speaker: Alexandra Carvalho Antunes De Oliveira (Peking University (CN))

BSM_HIggs_QCD_LHC_2025.pdf

12:30 → 14:00 Lunch Break

14:00 → 15:30 Heavy Quarks (including top and flavour physics): Parallel 2A

Convener: Philipp Böer

14:00 Photoproduction of charmonium-photon pairs in the CGC framework

In this talk, we present our results on $\eta_c\gamma$ and $\chi_c\gamma$ photoproduction in middle- and high-energy experiments, which can be studied in ultraperipheral kinematics at the LHC and the future EIC. Due to the onset of saturation in the small-$x$ region, the interaction of heavy quarks with the gluonic field of a nuclear target is described in the framework of the Color Glass Condensate framework. In this model, the cross section of the proposed $2\to 3$ processes is fully determined by the dipole forward-scattering amplitude, making them a probe for testing different parametrizations of this fundamental phenomenological object.

As a main result, we present numerical estimates of the cross sections and expected counting rates, based on the technical specifications of experimental setups such as the LHC and the future EIC. We found that the cross sections are sufficiently large to allow for a dedicated experimental study. Furthermore, our results are on par with recent predictions for this channel obtained in the collinear factorization approach. Along with that, we also estimated the role of these processes as a potential background to $\eta_c$ and $\chi_c$ photoproduction, which are considered among the possible tools for studying $t$-channel odderons. We found that the contribution from meson-photon production (with an undetected photon) is comparable to the expected odderon contribution in the small momentum transfer kinematics.

This talk is partially based on publication Phys.Rev.D 111 (2025) 5, 056024 (https://doi.org/10.1103/PhysRevD.111.056024)

Speaker: IVAN ZEMLIAKOV

QCDatLHC.pdf

14:22 Inclusive open charm photoproduction in ultraperipheral collisions at the LHC with G$\gamma$A-FONLL

Ultraperipheral heavy-ion collisions (UPCs) offer a clean way to study photon–nucleus interactions at high energy. In this talk, we present the first next-to-leading order predictions for inclusive $D^0$ production in Pb–Pb UPCs at the LHC, obtained with the new G$\gamma$A–FONLL framework. The framework relies on FONLL (Fixed-Order Next-to-Leading Logarithm) to model heavy-quark production in photonuclear collisions and employs a photon-flux reweighting procedure to describe the production cross sections in ultraperipheral heavy-ion collisions. The G$\gamma$A calculations are first validated against the photoproduction cross sections of $D^{*}$ in electron–proton collisions at HERA. The predictions for the $D^{0}$ production cross section in ultraperipheral Pb–Pb collisions at the LHC are then presented and compared to the first experimental results obtained by CMS at $\sqrt{\rm s_{\scriptscriptstyle NN}}=5.36~\text{TeV}$. The predictions are benchmarked against different choices of nuclear parton distribution functions, fragmentation functions, and renormalization and factorization scales.

Speaker: Anna Maria Stasto (Pennsylvania State University (US))

anna_stasto_qcdatlhc.pdf

14:45 ATLAS results on top quark mass and properties (including threshold)

The top-quark mass is one of the key fundamental parameters of the Standard Model that must be determined experimentally. Its value has an important effect on many precision measurements and tests of the Standard Model. The Tevatron and LHC experiments have developed an extensive program to determine the top quark mass using a variety of methods. In this contribution, the top quark mass measurements by the ATLAS experiment are reviewed. These include measurements in two broad categories, the direct measurements, where the mass is determined from a comparison with Monte Carlo templates, and determinations that compare differential cross-section measurements to first-principle calculations. In addition, new ATLAS results on top-quark properties are shown. This includes the first observation of quantum entanglement in top-quark pair events and tests of lepton-flavour universality.

Speaker: Mr Mohammed Ghani (University of Warwick)

QCDLHC25_TopPnM_ATLAS_MGhani.pdf

15:07 Resummation of super-leading logarithms in top-antitop production

It is well known that jet cross sections at hadron colliders receive double-logarithmic corrections, also referred to as super-leading logarithms. These corrections arise from two Glauber gluon interactions between the colliding partons. For processes involving massive final states, such as top-antitop production, additional sources of double logarithms emerge due to non-trivial singularities associated with the massive particles. We outline the procedure for determining the relevant color structures, resumming these new double logarithms, and study their magnitude relative to the usual super-leading logarithms from Glauber exchange.

Speaker: Dr Upalaparna Banerjee (JGU Mainz)

QCD@LHC_UB.pdf

14:00 → 15:30 Parton distribution functions: Parallel 2A

14:00 EPPS views on nuclear PDFs

I will discuss aspects of the global analysis of nuclear PDFs, particularly from the direction of the Eskola-Paakkinen-Paukkunen-Salgado (EPPS) framework.

Speakers: Hannu Paukkunen, Hannu Paukkunen

QCDatLHC25_Paukkunen.pdf

14:20 Towards CJ25 global fit

We discuss progress towards a new CTEQ-JLab (CJ) global PDF analysis --called CJ25-- that, for the first time in a global fit, includes the full set of JLab 6 GeV inclusive DIS measurements and the first published JLab 12 GeV data. The analysis focuses particularly on the large-x region, and carefully treats the interplay between higher-twist effects and off-shell nucleon corrections in low-energy data on proton and deuteron targets. We discuss their effect on both quark and gluon distributions, and outline how upcoming data may help unravel the nuclear and partonic dynamics in light nuclei.

Speakers: Matteo Cerutti (Christopher Newport University and Jefferson Lab), Matteo Cerutti (University of Pavia and INFN), Matteo Cerutti (Università di Pavia)

QCD@LHC.pdf

14:40 Revealing the fundamental character of the strong force: the nCTEQ Project:

Science is entering a new era in the investigation of nuclear matter,
driven by a wealth of precision data from the JLab, HERA, RHIC, & LHC
experiments. This work also forms the foundation for discoveries
at the future Electron-Ion Collider (EIC), which will address
fundamental questions about the nuclear mass, spin, and internal
structure. The culmination of these efforts will produce the most
detailed picture to date of nuclei, and advance the opportunity to
possibly “solve” the underlying QCD theory of strong interactions.

Speaker: Prof. Fred Olness (Southern Methodist University (US))

OLNESS_QCD4LHC.pdf

15:00 Structure of the pion and kaon from JAM global analysis of experimental and lattice data

Speakers: Wally Melnitchouk (Jefferson Lab), Wally Melnitchouk (Jefferson Lab)

melnitchouk.pdf

14:00 → 15:30 Perturbative and resummed predictions, parton showers and event generators for LHC and EIC: Parallel 2A

14:00 Measurement of multi-jets and vector boson plus jets production in ATLAS and CMS

Production of multiple jets or vector bosons plus jets at the LHC offers the main, and unprecedented opportunity to study QCD at the high-energy regime. As precision advances, attention has been brought up to study further topics sensitive to understanding of QCD: different topological configurations between vector bosons and jets, the jet substructure information, and the heavy-flavor components. In addition, these measurements are key ingredients to give precise determination of the strong coupling constants. This talk will summarize recent achievements from ATLAS and CMS on this topic.

Speaker: Radoslaw Piotr Grabarczyk (University of Oxford (GB))

GrabarczykQCDLHC.pdf

14:30 Dijet Photoproduction at NLO in POWHEG-Box

With the approval of the EIC, photoproduction processes have regained significant interest, underscoring the importance of their implementation in Monte Carlo event generators. In this context, I will present recent efforts to develop a POWHEG-BOX extension for simulating photon-induced dijet production at NLO, incorporating direct and resolved photon contributions utilizing the Weizsäcker-Williams Approximation. This implementation will enable event generation for collisions involving leptons, protons, and heavy ions, providing a versatile tool for ultra-peripheral collision (UPC) studies at the LHC and for making precision predictions for the EIC.

Speaker: Alexander Feike

QCDatLHC_PowhegPhotoproduction.pdf

15:00 Phase-space integrals through Mellin-Barnes representation and its application to SIDIS

We present a new analytic framework for phase-space integrals, central to precision collider physics. Angular components are computed through multifold Mellin–Barnes representations, producing results in terms of Goncharov polylogarithms for up to four denominators. We establish recursion relations that systematically reduce higher-power denominators. The angular part is combined with the radial integration via a careful treatment of singularities. Applications to NNLO QCD corrections in SIDIS will be discussed.

Speaker: Prof. Taushif Ahmed

qcdlhc2025_taushif.key

qcdlhc2025_taushif.pdf

15:30 → 16:00 Coffee Break

16:00 → 17:30 Heavy Quarks (including top and flavour physics): Parallel 2B

Convener: Philipp Böer

16:00 ATLAS Results on tt Cross Sections, Single Top, and Associated Top Quark Production

The exceptionally large dataset collected by the ATLAS detector at the highest proton-proton collision energies provided by the LHC enables precision testing of theoretical predictions using an extensive sample of top quark events. Measurements of the inclusive top quark production rates at the LHC have reached a precision of several percent and test advanced Next-to-Next-to-Leading Order predictions in QCD. Differential measurements in several observables are important to test SM predictions and improve Monte Carlo generator predictions.Recent measurements include total and differential top quark cross sections, as well as detailed studies of top quark production at various center-of-mass energies. This contribution presents the latest highlights from the ATLAS top quark physics program, including key measurements from Run II, and new results using Run III data.

The high center-of-mass energy of proton-proton collisions and the large available datasets at the CERN Large Hadron Collider allow the study of rare processes of the Standard Model with unprecedented precision. Measurements of rare SM processes provide new tests of the SM predictions with the potential to unveil discrepancies with the SM predictions or provide important input for the improvement of theoretical calculations. In this contribution, total and differential measurements of associated top-quark production are shown using data taken with the ATLAS Experiment at a center-of-mass-energy of 13 TeV. These measurements provide important bounds on the electroweak couplings of the top quark, often with Effective Field Theory interpretations and constrain backgrounds that are important in searches for Higgs production and for new phenomena beyond the SM.

Speaker: Mr Buddhadeb Mondal (Czech Academy of Sciences (CZ))

Buddhadeb_Mondal_QCDatLHC25_talk.pdf

16:23 Recent results on top quark physics from CMS

Top quark physics plays a central role in the LHC physics program, offering unique sensitivity to the Standard Model and potential new physics through precision measurements and rare processes. This talk will present recent results on top quark production and properties, with an emphasis on QCD aspects such as cross sections, differential measurements, and modeling improvements. Highlights will include new analyses and comparisons to state-of-the-art theoretical predictions.

Speaker: Beatriz Ribeiro Lopes (CERN)

QCD@LHC top talk.pdf

16:45 One-Loop QCD Corrections to $\bar{u}d \rightarrow t\bar{t}W$ at $\mathcal{O}(\varepsilon^2)$

Physical observables described by 2 → 3 scattering amplitudes have been a focal point of intense research in recent years. In particular, amplitudes with massive internal propagators are phenomenologically relevant as they represent the bottleneck of obtaining next-to-next-to-leading order (NNLO) QCD corrections to a variety of different processes, and at the same time pose interesting computational challenges. Among these processes, the associated production of a top-antitop pair with a W boson (ttW) is of particular interest. Not only is it relevant to searches for physics beyond the Standard Model, but it also serves as a significant background for important Standard Model processes.
As a first step towards an exact description of this process at NNLO in QCD, I present our analytic computation of the one-loop QCD corrections to this process up to finite order in dimensional regularization and a semi-numerical computation of the terms at higher orders. I will emphasise both open conceptual problems and technical challenges, highlighting a possible way forward to extend these results to the two-loop order.

Speaker: Sara Ditsch

Talk_Ditsch.pdf

17:07 Towards NNLO QCD corrections for off-shell ttx production

The production of top quarks at high-energy colliders plays a pivotal role in testing the Standard Model (SM) and in probing possible signs of new physics. In hadronic collisions, the primary source of top-quark events within the SM is top-quark pair ($t \bar t$) production and, since the top quark is unstable, the signature is almost exclusively characterised by two bottom quarks and the decay products of two $W$ bosons. In this talk, we focus on the so-called dilepton channel where both $W$ bosons decay leptonically.

With the increasing precision of current measurements and the expected sensitivity of future experimental analyses, accurate theoretical predictions for the complete $2 \to 6$ process, including all relevant off-shell effects, irreducible backgrounds and interferences, are essential. We present recent progress towards a next-to-next-to-leading (NNLO) QCD prediction for the off-shell $t \bar t$ production within the MATRIX framework, focusing on the theoretical developments and key challenges.

Speaker: Chiara Savoini

talk_Savoini.pdf

16:00 → 17:40 Parton distribution functions: Parallel 2B

16:00 Recent ATLAS measurement sensitive to or limited by PDF

Speakers: Gitanjali Poddar (ETH Zurich (CH)), Gitanjali Poddar (University of London (GB))

QCD@LHC.pdf

16:20 ALICE recent measurements and their impact to PDF extraction

Speaker: Anisa Khatun (Universita degli studi di Foggia (IT))

QCD@LHC2025_AK_V3.pdf

16:40 Uncertainty-Aware Discrimination of BSM Signatures in Embedding Spaces

Representing hadronic parton distribution functions (PDFs) through flexible, high-fidelity parameterizations remains a long-standing goal of particle physics phenomenology. One crucial goal is to quantitatively connect experiments’ sensitivity to underlying theory assumptions, including a broad array of BSM and SMEFT scenarios, to the properties of the PDFs’ flavor and x-dependence. We explore this problem by encoding many SMEFT scenarios in contrastive embedding spaces generated from simulated QCD events. Within this space we apply evidence-based uncertainty quantification techniques to disentangle data (aleatoric) and knowledge (epistemic) uncertainty while identifying out of distribution samples. Equivalently important is the ability to exclude particular classes of theories, such as standard model-only physics scenarios, which we do through the identification of theory “superclasses.” I will present the latest progress in building these embedding spaces unifying dozens of SMEFT variants, demonstrating how model discrimination and anomaly detection naturally emerge alongside generation and classification tasks with uncertainty quantification.

Speakers: Brandon Kriesten, Brandon Kriesten

Kriesten_QCDLHC25.pdf

17:00 Title: ALICE FoCal upgrade to investigate nonlinear QCD

The ALICE Forward Calorimeter (FoCal) upgrade is a key development aimed at enabling high-precision measurements in the largely unexplored regime of nonlinear QCD. Despite significant theoretical progress, direct experimental evidence of nonlinear QCD phenomena—such as gluon saturation at low Bjorken-x—remains limited. To address this, the ALICE collaboration has initiated the construction of a new forward detector, to be operational for Run 4 of the LHC. Positioned at very forward rapidities (3.4 < η < 5.8), FoCal will offer exceptional spatial resolution and ultra-fine granularity, making it uniquely capable of measuring direct photons, neutral mesons, and jets in a kinematic region sensitive to small-x gluons. These observables are critical for distinguishing between linear and nonlinear QCD evolution and for probing the onset of gluon saturation. By exploiting proton-proton and proton-nucleus collisions at the LHC in conjunction with FoCal's advanced capabilities, ALICE will be able to directly investigate the saturation scale and test the universality of parton distribution functions in nuclei. The FoCal upgrade thus represents a transformative step toward uncovering the nonlinear dynamics of QCD and deepening our understanding of the structure of strongly interacting matter under extreme conditions.

Speaker: Norbert Novitzky (Oak Ridge National Laboratory - (US))

ALICE-FoCal_QCD@LHC_Novitzky.pdf

16:00 → 17:30 Perturbative and resummed predictions, parton showers and event generators for LHC and EIC: Parallel 2B

16:00 Study of spin correlation in parton radiations

The spin-1 nature of gluon caused correlations in subsequent parton radiations insdie jets. Such effects were fully incorporated in limited parton shower models. The correlation is measured for the first time in experiments, and compared to MC models.

Speaker: Shuangyuan Wang (ZJU - Zhejiang University (CN))

qcd_lhc.pdf

16:30 A novel algorithm for spin correlations in parton evolution

Spin correlations between QCD emissions have so far been neglected in most of the parton shower algorithms commonly used for LHC predictions. However, their inclusion is crucial to achieve NLL accuracy or to include NLO contributions in these algorithms.
In this talk, we present a new algorithm for incorporating spin correlations into parton shower algorithms. Instead of using spin density matrices as in the Collins-Knowles algorithm, the common choice for this task, our algorithm relies on soft currents to exchange spin information between emissions. This has the advantage of reducing the number of amplitude evaluations and, thus, improving the performance compared to the standard algorithm. During the talk I will discuss the idea of the algorithm and the results of its first implementation for final-state particles. Once fully developed, it will be the basis for the inclusion of spin correlations in the parton shower code ALARIC.

Speaker: Mareen Hoppe (Technische Universitaet Dresden (DE))

Polarizationsimulation_MHoppe.pdf

17:00 Deep Inelastic Scattering with massive quarks

Lepton-proton Deep Inelastic Scattering (DIS) is a fundamental process for both the strong and weak sectors of the Standard Model, playing a crucial role in the measurement of the parton distribution functions of the proton, one of the main goals of the EIC program.
On the theory side, however, since the starting of the LHC operations, the community has been focused on QCD corrections to hadron-hadron collisions. Thus the calculation of many relevant matrix elements and their inclusion into general-purpose Monte Carlo codes for the precise simulation of DIS (lepton-parton) cross sections and distributions are still necessary.
We present the implementation of lepton-proton scattering in the DIS regime at NLO in QCD, with a massive quark pair in the final state, within the Monte Carlo event generator POWHEG-BOX. The code can be consistently matched to a parton shower program, delivering fully differential predictions with NLO QCD accuracy at the particle level.

Speaker: Clara Lavinia Del Pio (Brookhaven National Lab)

delpio_qcdatlhc2025.pdf

18:00 → 21:30 Conference Dinner

Friday 12 September

09:00 → 10:30 Plenary: Plenary 7

Convener: Philip Sommer (Technische Universitaet Dresden (DE))

09:00 Top quark modelling and recent results at the LHC

Speaker: Reinhard Schwienhorst (Michigan State University (US))

Top Schwienhorst

09:30 Precision Higgs Physics the LHC

Speakers: Raoul Horst Rontsch, Raoul Rontsch, Raoul Rontsch (U)

QCDatLHC_roentsch.pdf

10:00 SMEFT at EIC and LHC

Speaker: Anke Biekoetter (KIT Karlsruhe)

Biekoetter_QCDatLHC.pdf

10:30 → 11:00 Coffee Break

11:00 → 13:05 Plenary: Plenary 8

Convener: George Sterman

11:00 Machine Learning for QCD

Speaker: Vinicius Massami Mikuni (Lawrence Berkeley National Lab. (US))

Presentation with animations

11:30 Factorization and resummation beyond leading power

Speaker: Marvin Schnubel

MSchnubel_QCDatLHC.pdf

12:00 Introducing QCD@LHC26

Speaker: Claire Gwenlan (University of Oxford (GB))

QCD@LHC26announce.pdf

12:10 QCD@EIC

Speakers: Abhay Deshpande (Stony Brook University), Abhay Deshpande

Abhay Deshpande EIC QCD@LHC Present.pdf