Geant4 11.4 - patch-01 Release Notes
                 ------------------------------------

                                                           13 March 2026

List of fixes included in this public patch since release 11.4.0:

o CMake
  -----
  + Use CMake 3.16-3.19 compatible construction of interface libraries.
    Addresses problem report #2700.
    Fixed logic error in construction of link interface to such interface
    libraries that resulted in empty target creation/export.

o Geometry
  --------
  + magneticfield:
    o Fixed reported Coverity defect for restoring original stream
      precision in G4FieldManager::ReportBadEpsilonValue().

o Global
  ------
  + Always initialize G4CacheReference for a G4Cache instance on construction
    of latter; prevents fatal G4Exception when only low ID G4Cache elements
    are accessed.
    Protect debug warning printout from G4Cache destructor within 'g4cdebug'
    flag as it was originally intended. Addressing long-standing false-positive
    issue happening in MT mode (G4MTRunManager only) on macOS/clang.
    Also addressing problem report #2696.
  + G4VSIntegration: fixed reported Coverity defect.
  + Updated date and version for 11.4.1.

o Interfaces
  ----------
  + G4UIQt: reimplemented the command search feature for the Help tree,
    addressing problem report #2683.
    Fix in ComputeStringMatchScore(..) in setting number of elements for a
    QVector; use G4 types where appropriate. Fixed compilation warning for
    implicit type conversion on macOS/XCode.

o Particles
  ---------
  + Fixed energy conservation in G4MuonDecayChannel.
    Addressing problem report #2678.
  + Extented excited isomer name from 3 to 5 digits after dot; also
    addressing problem report #2680.

o Physics Lists
  -------------
  + constructors/electromagnetic:
    o G4EmStandardPhysics_option4: added possibility to use external dEdx
      tables for ions, through substitution of the G4LindhardSorencenIonModel
      model class by G4IonParameterisedModel. Addressing problem report #2703.
  + constructors/hadron_elastic:
    o G4ChargeExchangePhysics, G4ChargeExchangemessenger: added two different
      biasing factors for pions and kaons (request by NA64).
  + constructors/hadron_inelastic:
    o In G4HadronInelasticQBBC, return back cross-section
      G4ParticleInelasticXS for protons as it was in release 11.3.
    o Fixed segmentation fault occurring on Linux/gcc15/Debug/CXX23, caused
      by in-scope destruction of G4NeutronPHPBuilder instance used by
      G4NeutronBuilder in G4HadronPhysicsShielding.
  + lists:
    o G4PhysListFactory: trivial fix for reported Coverity defect.

o Processes - Electromagnetic
  ---------------------------
  + lowenergy:
    o G4LivermorePolarizedComptonModel: improved/corrected references to
      quantum entanglement papers.
 
o Processes - Hadronic
  --------------------
  + cross_sections:
    o G4ChargeExchangeXS: added two different biasing factors for pions and
      kaons (requested by NA64). Removed debug printout and fixed reported
      Coverity defect.
  + models/binary_cascade:
    o Fixed reported Coverity defects to avoid parameter string copy in
      G4BinaryCascade.
    o G4GeneratorPrecompoundInterface: added G4HadronicException header.
  + models/cascade:
    o Directly use std::cbrt(double) in G4InuclSpecialFunctions, as now
      standard and available in <cmath>, replacing old ad-hoc implementation.
      Minor code formatting.
  + models/coherent_elastic:
    o G4ChargeExchange: fixed bug in sampling of scattering angle for kaons.
    o G4ChargeExchange, G4HadronElastic, G4LMsdGenerator: minor optimisation.
  + models/fission:
    o Fixed reported Coverity defects in G4fissioner for avoiding unnecessary
      copy of strings.
    o Fixed layout of G4fissionEvent class.
  + models/inclxx:
    o In G4INCLCrossSectionsAntiparticles, corrected wrong formulae with
      isospins concerning the cross-sections N Nbar -> N Nbar + 2 pions.
    o In G4INCLNNToNSK2piChannel, fixed 'iso' condition.
    o Fixed reported Coverity defects for use of std::move() in G4INCLCascade
      and G4INCLNbarAtrestEntryChannel. Use G4 types consistently.
  + models/nudex:
    o Fixed reported Coverity defects in G4NuDEXPSF for avoiding unnecessary
      copy of strings.
  + models/particle_hp:
    o G4ParticleHPContAngularPar: reduced allocator fragmentation and memory
      churn in BuildByInterpolation() by removing unconditional deep copies
      of input angular distributions. Copies are now created only in case of
      self-aliasing, preserving correctness while avoiding excessive per-call
      heap allocations. Addressing problem report #2630.
    o G4ParticleHPNBodyPhaseSpace, G4ParticleHPInelasticCompFS: added
      G4HadronicException header.
  + models/parton_string:
    o Added G4HadronicException header where missing for self-consistency.
  + models/theo_high_energy:
    o G4TheoFSGenerator: added G4HadronicException header.
  + stopping:
    o G4HadronStoppingProcess, G4MuonicAtomDecay: added G4HadronicException
      header.

o Processes - Solid state
  -----------------------
  + channeling:
    o In G4ChannelingMaterialData, fixed reported Coverity defects for string
      parameters copying. Use consistently G4 types and minor code formatting.

o Run
  ---
  + Introduced UI command "/run/undertakeOptimisation" to force geometry
    optimisation and added to G4RunMessenger.
  + Re-enabled automatic instantiation of G4MaterialScanner in G4RunManager;
    material scanner is instantiated only for the master thread.
    Fix in G4MaterialScanner to delete G4Event object at the end of each
    event and make sure geometry is optimized before starting the scan.
    In G4MSSteppingAction, fixed average A and average Z taking number of
    atoms into account. In G4MatScanMessenger, prevent material scanner
    UI commands from broadcasting to worker threads; material scanner is
    centrally managed by the master thread.

o Visualization
  -------------
  + modeling:
    o In G4PhysicalVolumeModel, fix to replace the helper class
      G4PhysicalVolumeModelTouchable with a temporary G4TouchableHistory
      object when calling a nested parameterisation, building and maintaining
      a private G4NavigationHistory.
  + gMocren:
    o Fixed reported Coverity defect for unnecessary string copy in G4GMocrenIO.
  + OpenGL:
    o In G4OpenGLQtViewer, fix in G4wheelEvent() for Qt version < 5.14.
      Addressing problem report #2688.
    o G4OpenGLViewer: removed unnecessary #include statements.
  + ToolsSG:
    o G4ToolsSGSceneHandler: obtain applicable auxiliary edge flag.
      In AddPrimitive(..), fixed position of daughter of cloud-represented
      volumes. Addressing problem report #2691.
  + Tree:
    o Moved 'fVerbosityGuidance' to G4ASCIITree factory to fix sanitizer
      warnings. Addressing problem report #2699.
 
o Examples
  --------
  + advanced/dna/moleculardna:
    o Fixed display of error for 'SSBm_yield' in analysis macros.
  + extended/exoticphysics/channeling/ch2:
    o Correction in main() for fixing error at the end of execution when
      G4ChannelingFastSimModel is switched off.
    o Corrections in plot labels and some comments in the python scripts.
    o Fixed CMake script to copy also Jupyter notebook in the build folder.
    o Small corrections in comments in macro.
  + extended/medical/dna/chem6:
    o Fixed energy unit for LET(100).
    o Cleanup implementation in main(): use default random engine MixMax and
      use auto whenever appropriate.
    o Set 1 as number of threads in beam.in to clear run-time warnings and
      fix Windows crash on exit.
  + extended/medical/dna/dnadamage2:
    o Cleanup implementation in main(): use default random engine MixMax and
      use auto whenever appropriate.

 ----------------------------------------------------------------------------

                             Technical Notes
                             --------------- 

  o  This patch should be applied on top of release 11.4 series.
  o  Technical notes distributed for release 11.4 are also applicable and
     valid for this patch.

The code and rebuilt binary libraries for release 11.4.1 are available
through the Geant4 "Download" Web page.

Please refer to the Geant4 User Documentation for further information about
using Geant4.