The LHCb Collaboration has been using ROOT in its software framework from the beginning, in more or less efficient way. Here summarize the evolution of our use of ROOT to then glimpse into the possible paths in view of LHC Run4 and LHCb Upgrade 2.
Integration of an analysis of Higgs boson decaying to a pair of tau leptons into a ROOT-based C++ framework, making use of recent ATLAS Open Data release. The workflow demonstrates how modern analysis strategies can be easily implemented within a modular structure that combines event selection and object reconstruction. Particular emphasis is placed on the use of ROOT for handling large...
For a few years, INFN has been developing R&D projects in the context of CMS high-rate analyses in view of the challenges of the HL-LHC phase, starting in 2030. Since then, several studies have been implemented and as a result a prototype for an analysis facility has been proposed, in compliance with CMS analysis frameworks (e.g. based on Coffea, ROOT RDataFrame), and also adopting open-source...
Can we teach an LLM to plot experimental HEP data? Modern particle physics workflows increasingly depend on a complex software ecosystem that connects large datasets, distributed data delivery, and user-level analysis tools. We demonstrate how a Large Language Model (LLM) can act as a coding assistant that bridges these components. Starting from a high-level user request—such as “plot jet...
The NDMSPC project introduces an innovative THnSparse analysis framework for high-dimensional data, directly addressing the challenge of fitting N-dimensional histograms within memory. Our solution organizes the THnSparse structure into sub-chunks, optimizing memory efficiency and enabling scalable processing. Beyond numerical values, the framework allows bin content to be arbitrary objects,...
The High-Level Trigger (HLT) of the Compact Muon Solenoid (CMS) processes event data in real time, applying selection criteria to reduce the data rate from hundreds of kHz to around 5 kHz for raw data offline storage. Efficient lossless compression algorithms, such as LZMA and ZSTD, are essential in minimizing these storage requirements while maintaining easy access for subsequent analysis....
The compiler-research.org initiative aims to make compiler
research more visible, interconnected, and sustainable across academia
and industry. Beyond research infrastructure, it pioneers a new model
for open-source education and mentorship offering remote, project-based
training in advanced compiler and systems engineering for early-career
professionals. This approach fills a critical...
The Deep Underground Neutrino Experiment (DUNE) plans to collect physics
data for over 10 years, starting in 2029. The full DUNE design consists of four far
detectors with multiple 10 kT fiducial mass LArTPCs and a heterogeneous near
detector complex with 1300 km between them. This combination of technologies
and readout time scales is expected to require large storage volumes with on...
As a low background experiment at the intensity frontier, the SHiP experiment faces many unique computing challenges compared to collider experiments. At the same time, the experiment is small, with very limited person power, and everything is evolving quickly in preparation for the TDRs, including core parts of the software, which need to be replaced while avoiding disruption to future-proof...
Cross compilation allows the build of binaries of a software package for different platforms without the need to use different hardware and operating system for each platform beging supported. The Julia binary registry, uses it to ease the support of a number of platforms (ARM, x86, PowerPC combined with MacOS, Linux, and Windows). Support for the Julia binary registry has motivated this work...
A flexible and dynamic analysis environment, capable of efficiently accessing and processing distributed data and resources, is essential for High Energy Physics (HEP) in both current and future LHC operations. This contribution presents the development and evolution of a scalable analysis platform that combines open-source standards with the computing resources provided by the Italian...
Thanks to the recent technological advances, immersive virtual reality becomes a viable option in various areas, including data visualization. In this talk, we present NDMVR, a software solution for n-dimensional histograms visualization in web-based virtual reality. While NDMVR utilizes JSROOT for certain base functionalities, its distinct features are nested histogram support and reactive...
With the latest ROOT version (6.36), the RNTuple API is stable as well as its on-disk format: data written today will be readable with the future versions of ROOT. RNTuple is the successor of the TTree format, bringing many advantages such as faster read / write, type safety, use of modern smart pointers, suitability for parallelized hardware and asynchronous operations. SND@HL-LHC will be an...
The R3B (Reactions with Relativistic Radioactive Beams) experiment at GSI/FAIR is devoted to exploring the properties of nuclei located far from the valley of stability, with particular emphasis on their structure and reaction dynamics. To address these scientific objectives, a highly versatile reaction setup has been developed. This setup combines high detection efficiency, large geometrical...
REve is a rewrite of EVE for the ROOT-7 era, using modern C++ and relying on ROOT’s built-in http server for communication with GUI clients. Part of REve is also implemented in JavaScript and uses OpenUI5, JSROOT, and RenderCore as its foundation libraries.
FireworksWeb is a CMS application built around REve. Several advanced legacy Fireworks features have been ported into REve in an...
LHCb’s data analysis model is evolving rapidly in preparation for Run 5 and the HL-LHC era. This talk will outline how LHCb analysts perform end-to-end analyses, from data production to final physics results, and how these workflows differ from those of the general-purpose detectors. We will discuss the increasing demands on scalability, interoperability, and usability of analysis tools,...
CMS is developing FlashSim, a machine learning–based framework that produces analysis-level (NANOAOD) events directly from generator-level inputs, reducing simulation costs by orders of magnitude. Efficient integration of preprocessing, inference, and output is essential, and ROOT RDataFrame provides the backbone of this workflow.
Certain operations required for FlashSim are not yet part of...
Analyzing HL-LHC heavy-ion collision data with ALICE
Victor Gonzalez, Wayne State University (US),
on behalf of the ALICE Collaboration
The ALICE detector has been taking data at heavy-ion HL-LHC regime since the start of the LHC Run 3 Pb--Pb campaign in October 2023. Recording Pb$-$Pb collisions at 50 kHz and pp collisions up to 1 MHz interaction rates without trigger results in...
Parameter inference via unbinned maximum likelihood fits is a central technique in particle physics. The large data samples available at the HL-LHC and advanced statistical methods require highly efficient fitting solutions. I will present one such solution, MoreFit, and discuss in detail the optimization techniques employed to make it as efficient as possible. MoreFit is based on compute...
FairRoot is a software framework for detector simulation, reconstruction, and data analysis
developed at GSI for the experiments at the upcoming FAIR accelerator complex.
Started as a framework for experiments at the FAIR project, it is meanwhile also used by several experiments outside of GSI.
The framework is based on ROOT and Virtual Monte Carlo (VMC) and allows fast prototyping as well...
The BESIII experiment has been operating since 2009, to study physics in the $\tau$-charm energy region utilizing the high luminosity BEPCII (Beijing Electron-Positron Collider II) double ring collider. The BESIII Offline Software System (BOSS) is built upon the Gaudi framework, while also leveraging ROOT extensively across its various components.
The BESIII experiment primarily utilizes ROOT...
We present a new, modular framework for the processing of test beam data, and in particular for the R&D programme of future timing detectors.
Based on a C++ architecture, it aims to normalise workflows for the analysis of detector performances through the definition of standard and user-defined analyses (e.g. time discrimination algorithms, intrinsic time resolution, or inter-channel...
xRooFit, created in 2020 and integrated into ROOT as an experimental feature in 2022, is an API and toolkit designed to augment RooFit's existing functionalities. Designed to work with any RooFit workspace, xRooFit adds features to assist with workspace creation, exploration, visualization, and modification. It also includes a suite of functionality for statistical analysis, including NLL...
In a single programming language, Julia provides ease of programming (as Python), high running performance (as C++), and exceptional code reusability (with no comparison). These three properties make it the ideal programming language for high energy physics (HEP) data analysis, as demonstrated by several studies and confirmed by a growing interest from the HEP community. The ROOT.jl package...
We bring a core technology from high-energy physics to financial market surveillance. The HighLO project uses the ROOT framework to process terabytes of high-speed trading data where conventional tools fail. In this presentation, we'll showcase our deployed platform and demonstrate how it equips regulators with powerful tools to protect market integrity.
Gravitational Wave (GW) Physics has entered a new era of Multi-Messenger Astronomy (MMA), characterized by increasing GW event detections from GW observatories at the LIGO-Virgo-KAGRA collaborations. This presentation will introduce the KAGRA experiment, outlining the current workflow from data collection to physics interpretation, and demonstrate the transformative role of machine learning...
This contribution highlights practical uses of ROOT and JSROOT for data exploration and web-based visualization. We show performance improvements achieved by replacing matplotlib with JSROOT in the CalibView app for the CMS PPS project. A key feature is the partial reading of ROOT files and handling plot data as JSON objects.
We also present a lightweight approach using static websites...
CAR T-cell therapy has revolutionized cancer immunotherapy by reprogramming patient T cells to recognize and eliminate malignant cells, achieving remarkable success in hematologic cancers. However, its application to solid tumors remains challenging due to the complexity and heterogeneity of the tumor microenvironment. CARTopiaX is an advanced agent-based model developed on BioDynaMo, an...
A flexible and dynamic analysis environment, capable of efficiently accessing and processing distributed data and resources, is essential for High Energy Physics (HEP) in both current and future LHC operations. This contribution presents the development and evolution of a scalable analysis platform that combines open-source standards with the computing resources provided by the Italian...
The Deep Underground Neutrino Experiment (DUNE) will deploy four 10 kt
fiducial mass time projection chambers in order to study accelerator neutrinos,supernova neutrinos, beyond the standard model physics, atmospheric neutrinos,and solar neutrinos. Reconstructing data in varying time domains over the nearly 400,000 channels needed to monitor this volume presents the complex challenge of...
