Source code - Download area

List of fixes introduced since release 11.4.1 of last March: Notes

To install the patch, you should download the whole source tree including also the patch and recompile from scratch all libraries.

Excused: Mihaly Novak, Miguel Antonio Cortes-Giraldo

Please note : This is a transitional SB meeting

Part 1 - by the current SB membership

1. Approval of merging the Physics List Working Group into the Hadronic Physics Working Group

2. Annual census

• Finalising the annual census. On the main web site, together with the list of members and contributors, the overall self-declared and not audited FTE of the Collaboration is shown.

3. Approval of the election of Working Group leadership

• Note:
  • first name : working group coordinator, elected
  • second name in parenthesis : deputy coordinator, who takes over in case of coordinator absence, nominated
  • other name(s) : additional representative(s), elected, number of representatives depends of the working group FTE
  • Bold names are new SB members / deputies
• Advanced Examples
  • Francesco Romano (Miguel Cortes)
• Documentation Management
  • Alexandre Howard (Luis Sarmiento Pico)
• Electromagnetic Physics Processes
  • Luciano Pandola, Vladimir Ivanchenko, Daren Sawkey, Sebastien Incerti, Alexey Sytov
• Geometry and Transport
  • John Apostolakis (Andrei Gheata)
• Hadronic Physics Processes
  • Luis Sarmiento Pico, Alberto Ribon
• Generic Processes and Materials
  • Marc Verderi (Igor Semeniouk)
• Novice and Extended Examples
  • Ivana Hrivnacova (Anh Tuan Lee)
• Particles and Tracking
  • Shogo Okada (Hisaya Kurashige)
• Persistency
  • Witold Pokorski (Ivana Hrivnacova)
• Physics Validation and Tools
  • Dmitri Konstantinov (Alvaro Tolosa Delgado)
• Run, Event and Detector Responses
  • Makoto Asai (Ben Morgan)
• Software Management
  • Ben Morgan (Gunter Folger)
• Testing and Quality Assurance
  • Julia Yarba (Soon Yung Jun)
• User and Category Interfaces
  • Koichi Murakami (Hajime Yoshida)
• Visualization
  • Laurent Garnier (John Allison)
• Ex-officio
  • Spokesperson : Alberto Ribon
  • Deputy spokesperson : Ben Morgan
  • Release coordinator : Gabriele Cosmo
  • Technical Forum chair : Marilena Bandieramonte
  • Oversight Board liaison : Makoto Asai
• Election process and WG leadership approved by the transitional SB

Part 2 - by the new SB membership

4. Work Plan for 2026

• Work plans are published on the web in the various Working Group pages.
• Collaboration-wide development items is summarized and posted on the web.
• The Technical Forum, on April 2nd is devoted to the presentation and discussion of the work plan.

5. Open User Requirements

• On-going update of the user requirements, based on the presentations made at the Collaboration meeting at Stony Brook (20-24 October 2025). An overview is given at the Technical Forum on April 2nd.

6. Spokesperson election

• After the conclusion of the Working Group elections, the election of the spokesperson can start. The first part is to set-up the Candidate Nomination Team (CNT), made by the three members of the Steering Board.

7. Collaboration meeting

• The Geant4 Collaboration meeting (restricted to members and contributors) is scheduled in Bordeaux (France), on 5-9 October 2026.

8. Recent Events

• Technical Forum on 18 December 2025, https://indico.cern.ch/event/1615896/ dedicated to the presentation of the new Geant4 release, 11.4.

• 2026 Geant4-DNA International Tutorial, Bangkok, Thailand, 18-20 March 2026, https://indico.in2p3.fr/event/36861/

9. Future Events

• Technical Forum on April 2nd, https://indico.cern.ch/event/1659856/

• Geant4 Beginner Course, at CERN, 18-22 May 2026, https://indico.cern.ch/event/1657768/

• CHEP 2026 (end of May, in Bangkok, Thailand): https://indico.cern.ch/event/1471803/

• African School of Physics ASP2026, CEMESTEA, Nairobi (Kenya), July 5-19, 2026 : https://africanschoolofphysics.org/asp2026/

• Geant4 Tutorial Course at Jefferson Lab, Newport News, Virginia (USA), 20-24 July 2026

• International Geant4 School, ELI Beamlines Facility, Czech Republic, 27-31 July 2026, https://indico.eli-laser.eu/event/231/

• Geant4 (4 days) & Geant4-DNA (1 day) tutorial in Daejeon, Rep. Korea, Nov. 30 - Dec. 5, 2026

Meeting Date Monday, March 30, 2026 - 16:00 (CET)

NOTE: Items marked with (*) may or may not be achieved in 2026.

Configuration & Software Management

• Modularization of Geant4 Libraries - (1)/(2)
  • Identify libraries for merging or splitting, including optional components
  • Identify and reduce dependencies between components where possible
• Investigate use of GitLab/Hub CI as a possible replacement for Jenkins - (2)
  • Use for production of binary packages
  • Prepare migration plan for full CI workflows
• Update documentation, unit testing, and CPU/memory benchmarking of numerical methods and data structures - (2)

Electromagnetic physics & optical processes

• Infrastructure:
  • Parallel initialisation of EM physics - (1)
  • Restore possibility to use user stopping power tables for ions - (1)
  • EPICS-2017 gamma cross-sections as an alternative in standard models - (2)
• R&D - G4HepEm and AdePT:
  • Investigate extension to G4HepEm for covering ALICE simulation - (2)
  • Investigate extension to AdePT for including neutron transport - (2)
• High Energy Physics developments:
  • Model design for X-Ray processes - (2)
  • Analysis of evolution spin polarization - (2)
  • Implementation of thermal photon/inverse Compton - (2)
  • Inclusion of more crystalline materials and orientations in channeling data - (2)
  • Experimental validation and update of G4ChannelingFastSimModel, G4BaierKatkov, G4CoherentPairProduction processes - (2)
  • Implementation of a ML model trained on Particle-in-Cell simulations of laser-driven plasma wakefield acceleration as a particle source- (2)
  • Developments of high-order QED corrections to Bremsstrahlung - (2)
  • Complete the list of higher order effects included in EM models - (2)
• Low Energy Physics models:
  • Implementation of ion stopping power in plasma - (1)
  • Developments of plasma physics - (2)
  • Improvements of material handling - (2)
  • Extension of the MicroElec database - (2)
• Optical photon processes and X-ray physics:
  • Maintenance and optimisation of optical classes - (2)
  • Refactor quasi-scintillation and quasi-Cherenkov processes to support offloading of optical photon transport - (2)
  • Introduction of a model approach into Scintillation and WLS processes - (2)
  • Introduction of a new model for reflection from multilayer surfaces - (2)
• DNA physics & chemistry
  • Implementation of molecular excitation cross-section model - (1)
  • Update of model interface for O2, N2, CO2 models of ionisation, excitation and elastic scattering - (1)
  • Radio enhancement studies for gold nanoparticle - (2)
  • Extensions to DNA geometries - (2)
  • DNA double-strand break kinetics and repair pathways - (2)
  • Addition and improvement, verification and validation of Geant4-DNA physics models for liquid water (electrons, ions) and other materials - (2)
  • Revision of Geant4-DNA physics constructors - (2)
  • Implementation of cellular oxygen chemistry in Geant4-DNA - (2)
  • Implementation of Li and C cross-sections in Geant4-DNA - (2)
• Validation & Testing:
  • Validation of three-gamma annihilation of positrons - (2)
  • Verification of the accuracy of the adjoint for space applications - (2)
  • Validation MicroElec model for low-energy protons ionisation - (2)
  • Benchmarking of particle therapy applications - (2)
  • Verification & validation of Geant4-DNA chemistry - (2)

Geometry & Field Transport

• Use of multi-threading to speed up overlap checking for complex setups - (1)
• Improvements to parallel geometry initialisation for complex volumes- (1)/(2)
• Generation of full geometry path for a given volume name - (1)/(2)
• Improve robustness and performance of selected Geant4 solids - (1)/(2)
• Introduce strict(er) default accuracy for field propagation - (2)
• Enhancements to deliver higher GPU navigation performance, and restructure it for consistent behavior across CPU and GPU with a maintainable, portable code base (CUDA/HIP) - (2)
  • Simplification and standardisation of the navigation interface
  • Improvements to GPU navigation performance with new locality-aware accelerator
  • Replacement of recursion with iteration (esp. for Boolean solids)
  • Removal of vector constructs to simplify code and improve scalar performance
  • Addition of a portability layer and refactoring of device code to POD + explicit dispatch (no device virtuals)

Hadronic Physics

• String Models
  • Analysis of Lambda hyperon production in nucleus-nucleus interactions based on NA61/SHINE measurements - (1)/(2)
  • Analysis of Au+Au interactions with BES (RHIC) data - (1)/(2)
  • Improvements to simulation of deuteron properties - (1)/(2)
  • In QGS model, inclusion of finite energy corrections to the eikonal approximation - (1)/(2)
  • Improvement of light anti-nucleus - nucleus cross-sections at low energies using ALICE data - (1)/(2)
  • Improvement to the probability of production of charmed particles for soft hadron-proton and proton-nucleus interactions using experimental data - (1)/(2)
  • Improvement of the kinematical properties of charmed particles produced in hadron-proton interactions in QGS and FTF models using experimental data - (1)/(2)
  • Model parameter studies of BERT model - (1)/(2)
  • Investigation of open issue with longitudinal pion showers in ATLAS FCAL - (1)/(2)
  • Maintenance and improvement of the hadronic framework; code improvements of FTF and QGS models - (1)/(2)
• Intra-nuclear Cascade models
  • Code review and maintenance in Bertini-like (BERT) and Binary (BIC) models - (1)/(2)
  • Extension for antideuteron in Liege (INCLXX) model - (1)/(2)
  • Optimisation of parameters and propagation of uncertainties in INCLXX - (1)/(2)
• Precompound/de-excitation Models
  • Tuning of parameters in de-excitation, based on experimental data - (1)/(2)
  • Development of a new multi-fragmentation model - (1)/(2)
  • Addition of more fission modes in ABLA++ to improve the description of mass and charge distributions of fission fragments at low excitation energies - (1)/(2)
  • Optimisation of parameters in ABLA++ - (1)/(2)
• Radioactive Decay model
  • Implementation of user-defined spectrum for beta and beta+ decays - (1)/(2)
• High Precision (HP) Models
  • Implement the use of pre-Doppler broaden cross-section database at a given temperature; implementation of the algorithm that allows to do that at the beginning of a Geant4 simulation - (1)/(2)
  • Translation of new nuclear data library releases from the ENDF-6 format to the G4NDL format, and verification - (1)/(2)
  • Refinements to the integration of the NuDEX model into Geant4, and expand its usage (not only in neutron capture reactions) - (1)/(2)
  • Improvement and speed-up of Particle-HP code - (1)/(2)
• Low Energy Neutron Data Model
  • Updates to LEND and GIDI - (1)/(2)
• Hadronic Elastic Models
  • Review of the pion elastic scattering model - (1)/(2)
  • Improvements to elastic scattering of p+d, d+d, d+A, and other light nuclei at high energies using Glauber approximation - (1)/(2)
• Other models
  • Development and validation of gamma/lepton/neutrino - nuclear physics - (1)/(2)
  • Maintenance of the interface to FLUKA.CERN for hadron-nucleus inelastic cross-sections and final-state interactions - (1)/(2)
  • Use of Pythia8 as an external generator: application for LDMX experiment - (1)/(2)
  • Consolidation of the charge exchange of pions and kaons - (1)/(2)
  • Explore the possibility of emulating BLOB or a portion of it with DL and of a differentiable pipeline to optimize QMD and LIQMD free parameters - (1)/(2)
  • Updates to the QMD model, investigating the nucleon-nucleus inelastic cross-section; preparation of a new version of QMD based on a relativistic nuclear model - (1)/(2)
  • Muonic atoms developments - (1)/(2)
  • Implementation of the AMS (Adaptive Multilevel Splitting) variance reduction technique - (1)/(2)
• Validation & Testing
  • Creation of tests for validating the production of charmed particles in hadron-proton and proton-nucleus interactions - (1)/(2)
  • Validation of the alternative FermiBreakUp and GEM models - (1)/(2)
  • Coverage extension of hadronic tests for calorimeter test-beams and low-energy neutron tests - (1)/(2)
  • Hadronic validation using thin-target data and tests relevant to Fermilab experiments - (1)/(2)
  • Study of the sensitivity of the MC predictions to the variations of various parameters and development of needed infrastructure - (1)/(2)
  • Validation and support of hadron-therapy applications - (1)/(2)
• Hadronic Datasets
  • Refinements to Hadronic Datasets G4ENSDFSTATE, PhotonEvaporation, RadioactiveDecay - (1)/(2)
  • Update of G4PARTICLEXS based on room-temperature cross-sections of Particle-HP. Optimisation of accuracy, computational performance and memory footprint - (1)/(2)

Materials, Generic Processes and Parameterisations

• Fast Simulation
  • Revision and improments of GFlash models - (1)/(2)
  • Developments in AI-based fast simulation models - (1)/(2)
    • Introduction of optional and GPU-enabled tests for ML inference
    • Implementation of per-event batching
    • Development of high-granularity CaloDiT-2 (in view of CMS)
    • Studies of step-level shower data for preparation of point-cloud representations
• Biasing
  • Investigate overlap between generic and geometrical biasing - (1)/(2)
  • Prototyping of DXTRAN-like functionality - (1)/(2)
  • Biasing of charged particle interaction occurrence - (1)/(2)
  • Extend generic biasing scheme for at rest case - (1)/(2)
  • Design document for Implicit capture & implementation - (1)/(2)
• Materials
  • Code improvements - (1)/(2)
• Scoring
  • Refinements to parallel world scoring - (1)/(2)

Particles & Tracking

• Update of particle properties to latest 2026 PDG data - (1)/(2)
• Performance tests and improvements - (1)/(2)
• Polishing up code readability and documentation - (1)/(2)
• Re-design and implementation of G4ForceConditions - (1)/(2)

Persistency & Analysis

• Regular maintenance & extensions to GDML and analysis classes- (1)/(2)

Physics Lists

• Review of physics lists code - (1)/(2)
• Recommendation/documentation of physics-lists for specific use cases - (1)/(2)
• Maintenance and upgrade of the PenelopeEM physics constructor - (1)/(2)
• Review organisation of library structure to allow for optional libraries build - (1)/(2)
• Maintenance of the alternative/extensible physics list factory relevant to the Intensify-Frontier - (1)/(2)

Physics Validation and Tools

• Refactoring of existing ATLAS-based examples and implementation of new examples, e.g. silicon and muon chambers - (1)/(2)
• Inclusion of detailed vs fast simulation comparison/validation tests into geant-val - (1)/(2)
• Development of the Thin Target testing suite and completion of the rewrite of the SimplifiedCalo test - (1)/(2)
• Physics validation for microdosimetry with different hadronic and electromagnetic physics lists; comparison with published experimental data for protons and light ions - (1)/(2)
• Finalisation and publication of Compton scattering validation results; third validation cycle of electron energy deposition against Sandia 79 report data - (1)/(2)
• Integration of the LHCb SpaCal test-beam simulation application into geant-val and comparison with experimental test-beam data - (1)/(2)
• Finalisation of the GB03 general biasing validation work; regeneration of gflasha samples following correction of the Ec calculation; new gflash validation test for a sampling calorimeter - (1)/(2)
• Migration of the combined CMS ECAL+HCAL 2006 test-beam simulation from the CMSSW framework to a standalone Geant4 application and integration into geant-val - (1)/(2)
• Addition of LightIonBraggPeak to geant-val - (1)/(2)
• RAON beam simulation studies for physics validation - (1)/(2)

Run, Event, Detector Response & Scoring

• Split initialization from event processing and create its dedicated task - (1)/(2)
  • Enable the use of all available threads for initialization regardless of number of events to be processed
• Review of scoring in parallel world and validation of all primitive scorers - (1)/(2)
• Addition of drawing methods to probe scores - (2)
• Interface to HepMC3 with a new example - (2)
• Enhancements to material scanner utility and revision of ray-tracer - (2)

Visualisation and Graphics Representations

• Management:
  • Implementation of similar interactive behaviours across all interactive viewers - (2)/(*)
  • Implementation of generic “packaging” of data for optimal usage on GPUs - (2)/(*)
  • Gaussian splat rendering - (2)/(*)
• Qt GUI:
  • Reimplementation of usage of .ui file - (*)
• TSG driver:
  • Optimisation of GL-3.2 - (1)
  • Picking and pop-up menu - (2)/(*)
  • 2-D plots - (*)
• Ray Tracer:
  • Change default window to 1000x1000 - (1)
  • Refinements to shadow and mirror drawing - (2)
• Vtk driver:
  • Implementation of picking - (1)
  • Review all OGL features for availability in VTK driver - (1)/(2)
  • Solid cylinder for trajectory (option) to enable usage of exported data in a wide range of 3D applications - (1)/(2)
  • Option for sphere/circle and cylinder/line - (1)/(2)
  • Release of USD interface - (1)/(2)
  • GLTF interface - (1)/(2)
• Open Inventor:
  • Improved use/install of Coin library - (1)
  • Evolution for Qt6 compatibility - (1)/(2)
  • Work on reference path to move through the geometry - (*)
• Other drivers:
  • gMocren: design and implementation to get some attributes for drawing detectors - (1)/(2)

Advanced Examples

• Development of independent sensitive microdosimeters for simultaneous acquisition inside the exp_microdosimetry example - (1)
• Design of realistic numerical phantoms of C.elegans - (1)
• Code review and update of selected examples - (1)/(2)
• Implementation of reading/writing of phase space file in medical_linac example - (2)
• Inclusion of histograms in the IAEAphsp example - (2)
• New developments for the hadrontherapy example and related validation - (2)
• New cancer cell geometry development and implementation of plasmid DNA damage for the molecularDNA example - (2)
• Improvement of pulse-structure implementation under UHDR conditions for the molecularDNA example (2)
• Development and release of a new PlasmaML_PALLAS example - (2)
• Material handling update and modifications for the microelectronics example - (2)
• Update to the last version of Opticks and integration of Celeritas in the CaTS example and associated performance studies - (2)
• Development and implementation of a novel dosimeter for FLASH radiotherapy inside the eFLASH_radiotherapy example - (2)
• Update of ICRP110_HumanPhantoms and ICRP145_HumanPhantom, respectively adding ICRP143 pediatric voxel phantoms and ICRP156 pediatric mesh phantoms - (2)

Novice & Extended Examples

• Add flexibility for changing geometry between runs to GFlashA - (1)/(2)
• New gflash example for sampling calorimeter - (1)/(2)
• New example demonstrating Julia bindings - (1)/(2)
• New example with ion Geant4-DNA cross-sections - (1)/(2)
• New example to examine all primitive scorers - (1)/(2)
• New example interfacing with HepMC3 - (1)/(2)
• Continue application of coding guidelines - (1)/(2)
• Implementation of HEP related examples/tests for AdePT for inclusion in nightly/CI - (2)
• New example to illustrate the use of the Inverse Compton Scattering event generator - (2)
• Reverse MC example coupling Reverse and Biasing framework (for force interaction in target volume) - (2)
• Improvements to the Par04 example brought from the experience of implementation for the experiments - (2)
• Medical/DNA:
  • Management of different geometries (shape, dimensions, materials) in icsd example - (1)/(2)
  • Incorporation of the calculation of (weighted) energy imparted to the site per proton collision in microtrack example - (1)/(2)
  • Improvements to molcounters example - (1)/(2)
  • Extension to neuron example, to continue studies of DNA damage using intermediate-Z ions (He, Li, N, Ne) and validation of the new detailed chromatin/chromosome geometries - (1)/(2)
  • Update of scavenger example for different time-step models (IRT-syn, SBS) - (1)/(2)
  • Code refactoring in wholeNuclearDNA example - (1)/(2)
  • Update to UHDR example for multipe pulse, benchmarking - (1)/(2)

Deadlines

• First semester - 26 June 2026
• Second semester - 4 December 2026

Source code - Download area

List of fixes introduced since release 11.4.0 of last December: Notes

To install the patch, you should download the whole source tree including also the patch and recompile from scratch all libraries.

Present: A. Ribon, B. Morgan, M. Asai, A. Tolosa-Delgado, D. Konstantinov, I. Hrivnacova, S. Incerti, S. Y. Jun, I. Semeniouk, A. Sytov, G. Cosmo, V. Ivanchenko, L. Thulliez, J. Apostolakis, F. Romano, M. Cortes-Giraldo, S. Okada, M. Novak (number: 18)

Excused: K. Genser, D. Sawkey, M. Verderi

1. Release 11.4

• Rather smooth release, without any particular issue (in either physics or performance).
• A more strict rule for late Merge Requests, close to the release deadline, appears necessary.

2. Fourth general paper

• Discussed the status and the authors.
• Expected to be published in late 2026.

3. Working Group Coordinator/Deputy Elections

• In the first part of 2026, the election of the Working Group coordinators and deputies will be held. After that, the spokesperson election will follow.

4. New User Requirements

• On-going update of the user requirements, based on the presentations made at the Collaboration meeting at Stony Brook (20-24 October 2025).

5. Past events

• Geant4 Advanced Course at CERN, 3-7 November 2025, https://indico.cern.ch/event/1584130/
• Technical Forum on December 18th devoted to the presentation of the new release 11.4, https://indico.cern.ch/event/1615896/

6. Future events

• 2026 Geant4-DNA International Tutorial, Bangkok, Thailand, 18/20 March 2026, https://indico.in2p3.fr/event/36861/
  • 30 places, already full.
• Next Technical Forum, dedicated to the presentation of the plan of work for 2026, expected in early Spring 2026.

Meeting Date Wednesday, December 18, 2025 - 8:00 CET

Release notes - Notes

Source code - Download area

Updated documentation - User guides

Present: Marc Verderi, Alberto Ribon, Ben Morgan, Sebastien Incerti, Francesco Romano, Ivana Hrivnacova, Witold Pokorski, Soon Yung Jun, Alexei Sytov, Vladimir Ivanchenko, Dmitri Konstantinov, Krzysztof Genser, Makoto Asai, Gabriele Cosmo, Alex Howard, Alvaro Tolosa-Delgado, John Apostolakis, Loic Thulliez, Andrei Gheata. (number: 19)

Excused: Mihaly Novak, Shogo Okada.

1. Collaboration Meeting in Stony Brook (USA) on 20-24 October

• In the same week, a Technical Forum was held.
• The next Collaboration Meeting will be held in CIEMAT, Madrid, Spain, in Autumn 2026 (the exact date is not yet fixed).

2. Change of the coordination of the Physics Lists Working Group

• Alberto Ribon will take over Krzysztof Genser’s coordination of the Physics Lists Working Group starting from October 30th, till the next election of in Spring 2026.
• Gunter Folger continues in his role of deputy coordinator.

3. Restructuring of the Working Groups for the elections in 2026

• Some re-organization of the Working Groups is under discussion for the elections in Spring 2026, with the goal of enhancing communication and synergies among the members and categories.

4. Geant4 release 11.4

• The minor release 11.4 is expected for December 5th.

5. Events

5.1 Past Events

• Fermilab 2025 Spring Geant4 Talk Series: https://indico.fnal.gov/category/1681/ (the website is not available without Fermilab associated account)
• Geant4 Tutorial Course at Jefferson Lab, USA, 18-22 August 2025, https://indico.jlab.org/event/963/
• Introductory lessons and hands on Geant4 at the 2nd Intensive School on Laser, Plasma and Fusion, at Budva, Montenegro, 22-25 September 2025, https://school2025.ca-probono.eu/
• Geant4 Workshop for Medical Physics in Adelaide, Australia, 1 October 2025, https://iupesm.org/geant4-workshop-for-medical-physics-october-1-wednesday/
• Geant4 Collaboration meeting, Stony Brook, United States, 20-24 October 2025 https://indico.cern.ch/event/1554191/
• Geant4 Technical Forum, Stony Brook, United States, 23 October 2025, https://indico.cern.ch/event/1588579/

5.2 Next Events

• Geant4 Advanced Course at CERN, 3-7 November 2025, https://indico.cern.ch/event/1584130/
• Geant4 Technical Forum at CERN, on 18 December 2025, dedicated to the presentation of the new Geant4 release 11.4.
• 2026 Geant4-DNA International Tutorial, Bangkok, 18-20 March 2026, https://indico.in2p3.fr/event/36861/

Meeting Date Friday, October 24, 2025 - 14:00

Present: Alberto Ribon, Dmitri Konstantinov, Ben Morgan, Soon Yung Jun, Gabriele Cosmo, Luis Sarmiento Pico, Sebastien Incerti, Krzysztof Genser, Ivana Hrivnacova, Francesco Romano, Daren Sawkey, Marc Verderi, Witek Pokorski, Igor Semeniouk, Makoto Asai, Alvaro Tolosa-Delgado, Alexander Howard, Alexei Sytov, Vladimir Ivantchenko , John Apostolakis, John Allison (number: 21)

Excused: Shogo Okada, Mihaly Novak

1. Status of computing performance benchmarks

  The CPU performance of Geant4 in the 11.3 series has remained stable,
  with no significant regressions observed so far.
  The observed memory increase in the single-particle samples starting
  from ref03 is due to the retrieval of additional cross-section data
  during initialization - for example, from
  G4NeutronInelasticXS::Initialise. However, this increase is not
  noticeable in the Higgs sample after the last event, as the added memory
  at initialization is relatively small compared to the total memory
  footprint of more complex events.

2. Open bug reports

  Most of the meeting was devoted to the review of open bugs, with
  several updates being made.

3. Status of the 11.4.beta release

  In progress. Some remaining issues on Windows, due to platform/hardware
  problems.
  Release date on Thursday 26th June.

4. Update on the copyright holders

  CEA Saclay and LLNL (Lawrence Livermore National Laboratory) have been
  added.

5. Status of the delta-assessment of AdePT & Celeritas

  The assessment report - for the delta-assessment of AdepT & Celeritas
  held on 26/27 March - is expected by the end of June.

6. Future events

  Geant4 course at the XXII Seminar on Software for Nuclear, Subnuclear
  and Applied Physics, Porto Conte Alghero (Italy), 8-13 June 2025,
  https://agenda.infn.it/event/44438/

  Geant4 Tutorial Course at Jefferson Lab, Jefferson Lab, Newport News,
  Virginia (USA), 18-21 August 2025,
  https://indico.jlab.org/event/963/

  Introductory lessons and hands on Geant4 at the 2nd Intensive School
  in Laser, Plasma & Fusion, Budva, Montenegro, 22-25 September 2025,
  https://school2025.ca-probono.eu/

  Next Technical Forum on October 23rd,
  https://indico.cern.ch/event/1554191/manage/timetable/#20251023

Meeting Date Thursday, June 12, 2025 - 16:00 CET