ROOT Users Workshop 2025

from Monday, 17 November 2025 (08:00) to Friday, 21 November 2025 (13:30)


        : Sessions
    /     : Talks
        : Breaks
17 Nov 2025
18 Nov 2025
19 Nov 2025
20 Nov 2025
21 Nov 2025
AM
08:00 Workshop registration  
09:00
Morning Session I (until 10:30)
09:00 Welcome from the Local Organisers  
09:10 An overview of the ROOT project - Danilo Piparo (CERN)  
09:30 Physics at the HL-LHC scale - Arantza Oyanguren (IFIC - Valencia)  
10:00 FCCAnalyses: a ROOT-based Framework for End-to-End Physics Analysis at the FCC - Juraj Smiesko (CERN)  
10:30
Coffee Break (until 11:00)
11:00
Morning Session II (until 13:00)
11:00 ALICE - Sandro Christian Wenzel (CERN)  
11:30 ATLAS - Gordon Watts (University of Washington (US)) Vincenzo Innocente (Fermi National Accelerator Lab. (US))  
12:00 CMS - Philippe Canal (Fermi National Accelerator Lab. (US))  
12:30 ROOT in the LHCb Software Framework - past, present and future - Marco Clemencic (CERN)  
08:55 Announcements - Danilo Piparo (CERN)  
09:00
Morning Session I (until 10:30)
09:00 WLCG - technical evolution - Alessandro Di Girolamo (CERN)  
09:30 Behind the "root://": Current state and future challenges of Physics data storage at scale - Cedric Caffy (CERN)  
10:00 Belle II - Thomas Lück  
10:30
Coffee Break (until 11:00)
11:00
Morning Session II (until 13:00)
11:00 Overview of the current RDataFrame efforts - Marta Czurylo (CERN) Stephan Hageboeck (CERN) Dr Vincenzo Eduardo Padulano (CERN)  
11:20 Benchmarking ROOT-Based Analysis Workflows for HL-LHC: The CMS INFN AF Use Case - Luca Pacioselli (INFN, Perugia (IT))  
11:40 Discussion  
12:00 Vibe Plotting: ServiceX, RDataFrame, and a LLM - Gordon Watts (University of Washington (US))  
12:20 NDMSPC: Addressing THnSparse Challenges in High-Dimensional Analysis - Martin Vala (Pavol Jozef Safarik University (SK))  
12:40 Discussion  
09:00
Morning Session I (until 10:15)
09:00 The View from Deep Underground: DUNE’s Perspective on ROOT - Jeremy Wolcott Andrew Paul Olivier (Argonne National Laboratory)  
09:30 Desiging and evolving a (Py)ROOT based software framework for SHiP - Oliver Lantwin (Universitaet Siegen (DE))  
10:00 Innova Physics UPV: Acceleration Brings Hope - Mateo Gajić Sales (Universitat Politecnica de Valencia)  
10:15
Poster session (until 11:00)
10:16 Cross compilation of the ROOT libraries - Philippe Gras (Université Paris-Saclay (FR))  
10:16 Enhancing CMS data analysis with Distributed RDF on a high-rate platform - Tommaso Diotalevi (Universita e INFN, Bologna (IT))  
10:16 NDimensional Visualization in 3D Virtual Environments - Daniel Chovanec (Technical University of Košice (SK))  
10:16 RNTuple for SND@HL-LHC - Filippo Mei (Universita e INFN, Bologna (IT))  
10:16 The R3BRoot framework - Pablo Gonzalez Russel (University of Santiago de Compostela)  
10:17 Batch generation for ML training - Martin Foll (University of Oslo (NO))  
10:17 GPU Accelerated Analyses - Lukas Breitwieser (CERN) Devajith Valaparambil Sreeramaswamy  
10:17 JSROOT and Web-graphics - Serguei Linev (GSI Darmstadt)  
10:17 On the Path to ROOT 7 - Stephan Hageboeck (CERN)  
10:17 RDF – (distributed) interactive analysis on 1000 cores - Dr Vincenzo Eduardo Padulano (CERN) Stephan Hageboeck (CERN) Marta Czurylo (CERN)  
10:17 Recent Cling Developments - Devajith Valaparambil Sreeramaswamy  
10:17 REve - Matevz Tadel (Univ. of California San Diego (US)) Serguei Linev (GSI Darmstadt) Alja Mrak Tadel (Univ. of California San Diego (US))  
10:17 RNTuple – Helping to meet the HL-LHC Storage Challenge - Jakob Blomer (CERN) Giacomo Parolini (CERN)  
10:17 ROOT viewer for CERNBox - Diogo Castro (CERN)  
10:17 ROOT – Development process, CI and distribution - Danilo Piparo (CERN)  
10:17 Teaching ROOT - Marta Czurylo (CERN)  
10:17 The new Python Interface - Vipul Nellamakada (Ramaiah University of Applied Sciences (IN)) Silia Taider (CERN) Aaron Jomy (CERN)  
10:17 UHI for ROOT: Interfacing With Python Statistical Analysis Libraries - Silia Taider (CERN)  
10:30
Coffee Break (until 11:00)
11:00
Morning Session II (until 13:00)
11:00 LHCb Data Analysis Towards Run 5: Challenges and Needs for ROOT - Jiahui Zhuo (Univ. of Valencia and CSIC (ES))  
11:20 Usage of EDM4hep datamodel in RDataFrame - Juraj Smiesko (CERN)  
11:40 Discussion  
12:00 CMS FlashSim and ROOT RDataFrame for ML-Based Event Simulation - Filippo Cattafesta (Scuola Normale Superiore & INFN Pisa (IT))  
12:20 Analyzing HL-LHC heavy-ion collision data with ALICE - Victor Gonzalez (Wayne State University (US))  
12:40 Discussion  
09:00
Morning Session I (until 10:30)
09:00 Innovative Services for Federated Infrastructures - Deployment and Execution in the Computing Continuum  
09:30 The FairRoot framework - Florian Uhlig (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE))  
10:00 The Utilization of ROOT in the BESIII Offline Software System - Mr Jiaheng Zou (IHEP, Beijing)  
10:30
Coffee Break (until 11:00)
11:00
Morning Session II (until 13:00)
11:00 RNTuple advanced topics - Giacomo Parolini (CERN)  
11:20 Future of ROOT I/O - Florine Willemijn de Geus (CERN/University of Twente (NL))  
11:40 Discussion  
12:00 TDAnalyser - a modular framework for the analysis of test beam data - Laurent Forthomme (AGH University of Krakow (PL))  
12:20 The ROOT 7 Release Series - Stephan Hageboeck (CERN)  
12:40 Discussion  
09:00
Morning Session I (until 10:30)
09:00 Market Surveillance at Scale: A Deployed ROOT Framework for Financial Integrity - Dr Philippe Debie (Wageningen University) Prof. Joost Pennings (Wageningen University)  
09:30 LIGO-VIRGO-KAGRA - Bridging Gravitational Wave and High-Energy Physics Software - Marco Meyer-Conde (Tokyo City University (JP), University Of Illinois (US))  
10:00 The outside view on ROOT - FERNANDO HUESO GONZALEZ  
10:15 Beyond HEP: ROOT for Solar Resources - Daniel Perez Astudillo  
10:30
Coffee Break (until 11:00)
11:00
Morning Session II (until 12:15)
11:00 JSRoot in Web Applications for High-Energy Physics: From Interactive Visualizations to Particle Transport Simulations - Leszek Grzanka (AGH University of Krakow (PL))  
11:15 CARTopiaX: an Agent-Based Simulation of CAR T-Cell Therapy built with ROOT and BioDynaMo - Salvador de la Torre Gonzalez  
11:30 Workshop discussions and closing - Danilo Piparo (CERN)  
PM
13:00
Lunch Break (until 14:30)
14:30
Afternoon session I (until 15:00)
14:30 Software at CERN between 1980's and 2000 - Rene Brun  
14:45 30 years of ROOT - Fons Rademakers (CERN)  
15:00
Afternoon session I (until 16:30)
15:00 ROOT Training Session - Silia Taider (CERN) Dr Vincenzo Eduardo Padulano (CERN) Marta Czurylo (CERN)  
16:30
Coffee Break (until 17:00)
17:00
Afternoon Session II (until 18:30)
17:00 Implementation of an $H\rightarrow \tau\tau$ Analysis within a ROOT-based C++ Framework using ATLAS Open Data - Morvan Vincent (Univ. of Valencia and CSIC (ES))  
17:20 ROOT Training Session - Silia Taider (CERN) Dr Vincenzo Eduardo Padulano (CERN) Marta Czurylo (CERN)  
18:30
Social programme (until 20:00)
18:30 Welcome Reception  
13:00
Lunch Break (until 14:30)
14:30
Afternoon session I (until 16:30)
14:30 ROOT I/O: Overview - Jakob Blomer (CERN)  
14:50 A first look at RFile - Giacomo Parolini (CERN)  
15:10 Discussion  
15:30 Performance Comparison of Lossless Compression Algorithms on CMS Data using ROOT TTree and RNTuple - Simone Rossi Tisbeni (Universita Di Bologna (IT))  
15:50 User Story: Integration of ROOT RNTuple to CMSSW's SoA data structures - Markus Holzer (CERN)  
16:10 Discussion  
16:30
Coffee Break (until 17:00)
17:00
Afternoon Session II (until 18:30)
17:00 An overview of ROOT in Python  
17:10 The ROOT Python Bindings Features - Silia Taider (CERN)  
17:30 Compiler Research in the Open: Connecting People, Projects, and Progress - Vassil Vasilev (Princeton University (US))  
17:50 Discussion  
13:00
Lunch Break (until 14:30)
14:30
Afternoon session I (until 16:30)
14:30 Statistical Inference in HEP - An Overview - Jonas Eschle  
14:50 RooFit overview - Jonas Rembser (CERN)  
15:10 Discussion  
15:30 Efficient Parameter Inference with MoreFit - Christoph Michael Langenbruch (Heidelberg University (DE))  
15:50 High performance analysis in CMS - Josh Bendavid (CERN)  
16:10 Discussion  
16:30
Poster session (until 17:00)
18:00
Social programme (until 22:30)
18:00 Guided Tour  
20:30 Workshop Dinner  
13:00
Lunch Break (until 14:30)
14:30
Afternoon session I (until 16:30)
14:30 Speeding up large-scale likelihood fits with Automatic Differentiation in RooFit - Jonas Rembser (CERN)  
14:50 Highlights of xRooFit - The High-Level API for RooFit - Will Buttinger (Science and Technology Facilities Council STFC (GB))  
15:10 Discussion  
15:30 Statistical inference in CMS with Combine - Aliya Nigamova (Paul Scherrer Institute (CH))  
15:50 Statistical Inference in ATLAS - Tomas Dado (CERN)  
16:10 Discussion  
16:30
Coffee Break (until 17:00)
17:00
Afternoon Session II (until 18:30)
17:00 Advancing Python-C++ Interoperability in ROOT and beyond - Vipul Nellamakada (Ramaiah University of Applied Sciences (IN)) Aaron Jomy (CERN)  
17:20 ROOT.jl, opening ROOT to the Julia programming language - Philippe Gras (Université Paris-Saclay (FR))  
17:40 Zero-overhead ML training with ROOT - Martin Foll (University of Oslo (NO))  
18:00 Discussion