Improvements over 3.4.*
(Important contributions by non-GENIE authors are especially acknowledged in the text below)

New comprehensive model configurations and tunes:

New and/or updated physics models:

• Addition of the published Minoo Kabirnezhad (MK) single-pion cross-section model by the Dubna GENIE group, and a critical review of the published work leading to model variants currently under consideration for GENIE v4. Details of the original model can be found in Phys. Rev. D 97, 013002. Details of the MK model variants are currently private. Contribution by Minoo Kabirnezhad (Oxford). [GENIE pull request #130], [GENIE pull request #131], [GENIE pull request #132].
• Implementation of a full simualtion chain independent from Pytha6 that uses Pythia8. This follows the announcement that ROOT will drop the support for pythia6. The contribution includes 3 PRs. Contribution by Robert Hatcher (Fermilab). [GENIE pull request #408], [GENIE pull request #410], [GENIE pull request #409]. Only the first two at the moment are merged as this sets the default configuration to still using pythia6. We will merge also the last one eventually, which sets the default to pythia8.

Event generation and core framework improvements:

• Allow algorythms to be used in reweight and add Professor as an optional dependency [GENIE pull request #366].

Improvements in generator tools (flux and geometry drivers, event generation and other apps):

Other improvements / bug fixes:

Other comments:

Improvements over 3.4.0
(Important contributions by non-GENIE authors are especially acknowledged in the text below)

Improvements in generator tools (flux and geometry drivers, event generation and other apps):

• Implementation of the correct time shift for GSimpleNtpFlux class when users shift the starting z coordinate for a neutrino ray off of the flux window. [GENIE pull request #387].

Other improvements / bug fixes:

• Fix how 3rd party FSI handle nuclear remnants [GENIE pull request #373] and binding energy [GENIE pull request #367].
• Allow reweight to define algorithms, in order to access configurations [GENIE Reweight pull request #25] and [GENIE pull request #366].

Other comments:

• The splines for v3.04.00 are valid for v3.04.02 as well.

Improvements over 3.2.2
(Important contributions by non-GENIE authors are especially acknowledged in the text below)

New and/or updated physics models:

• Addition of a spectral function-like approach for binding energies. Contribution by Steven Dolan and Laura Munteanu . [GENIE pull request #249].

New comprehensive model configurations and tunes:

• Added CMC desired by SBN and DUNE experiments: AR23_20i_00_000. [Readme file].

Beyond Standard model:

• Addition of Beam-produced Heavy Neutral Leptons. Contribution by John Plows (Oxford) . [GENIE pull request #223].

Other improvements / bug fixes:

• Fix in HAIntranuke about random number generation. [GENIE pull request #241].
• Fix in the hadronisation rotation. Contribution by Qiyu Yan . [GENIE pull request #264].

Improvements over 3.0.0

Technical developments

• Change in header file includes to fix compilations issues found in some platforms.

Improvements over 3.0.*
(Important contributions by non-GENIE authors are especially acknowledged in the text below)

New comprehensive model configurations and tunes:

• For every alternative cross-section model construction, released two new comprehensive model variants by incorporating the INCL (Liege) and GEANT4/Bertini FSI codes, in addition to the existing variants incorporating the INTRANUKE/hA and INTRANUKE/hN FSI codes. So, for example, for our G18_02 (theory) cross-section model construction, that incorporates the results of the GENIE 02_11b global analysis, users can obtain the following tunes: G18_02a_02_11b (hA FSI), G18_02b_02_11b (hN FSI), G18_02c_02_11b (INCL), G18_02d_02_11b (Bertini). Further details on the available tunes can be found here
• Incorporated the final results of the GENIE global analysis of bare-nucleon cross-section data into all G18_[01a-d/02a-d]_02_11b GENIE tunes. Preliminary versions of our results were released in v3.0.0 - v3.0.6 in tunes carrying the label 02_11a. These preliminary (02_11a) were maintained in v3.2.0, but they will be phased out is the next release. Details about this GENIE analysis are published in Phys.Rev.D 104 (2021) 7, 072009.
• Added 02_11b variants (tunes) for the G18_10 class of comprehensive models.
• Released optional AGKY hadronization model configurations, incorporating the first results from the GENIE global analysis of data on neutrino-induced hadron shower characteristics Details about this GENIE analysis are published in Phys.Rev.D 105 (2022) 1, 012009.
• Released a new set of tunes optimised for our ultra high energy user communities, based on our new NLO DIS cross-section calculation and event generation modules. They are: GHE19_00a_00_000 (BGR18 model), GHE19_00b_00_000 (CMS11 model), GHE19_00c_00_000 (GENHEN-like model) and GHE19_00d_00_000 (GGHR20 model).
• Released a new comprehensive model (GVLE18_01a) optimised for our low energy (< 100 MeV) user communities.
• Released a series of experimental comprehensive models incorporating new cross-section modelling elements (SuSAv2) in preparation of a new generation of comprehensive models and tunes for GENIE4.

New and/or updated physics models:

• Addition of the SuSAv2 1p1h and 2p2h cross-section models. Details published in Phys. Rev. D 101, 033003. Contribution by Stephen Dolan, Guillermo Megias and Sara Bolognesi (Ecole Polytechnique and IRFU, Saclay, DPP). [GENIE pull request #55]
• Addition of a new NLO DIS cross-section calculation and event generation modules (HEDIS package), including an implementation of the LEPTO interface to the PYTHIA6 hadronization routines, tested/validated up to 1E+9 GeV, in support of GENIE users in km3net, IceCUBE and CERN Forward Physics Facility (FASERnu and other experiments). Details published in JCAP 09 (2020) 025 and PoS ICRC2019 (2020) 895. This model requires a new GENIE external dependence: APFEL DGLAP evolution code. New generalised interfaces for structure function calculations. Contribution by Juan Rojo, Rhorry Gauld and Aart Heijboer (NIKHEF) in collaboration with core GENIE member Alfonso Garcia (IFIC/Harvard).
• New HELepton package, incorporating a) resonant interactions with the nucleon's photon field, and b) coherent neutrino scattering into the GENIE high energy event generator. Details in JCAP 09 (2020) 025. These processes were implemented at NLO. In addition, the new HELepton package absorbed old code to simulate the Glashow resonance and was re-implemented at NLO. [GENIE pull request #161]
• Addition of the Liege intranuclear rescattering model through an interface to the INCL generator. This model requires a new GENIE external dependence: INCL.
• Addition of the Bertini intranuclear rescattering model through an interface to the GEANT4 generator. This model requires a new GENIE external dependence: GEANT4. Contributions by Dennis Wright and Makoto Asai (SLAC).
• Addition of a first working interface the PYTHIA8 hadronization code, as part of an alternative, experimental configuration of the AGKY hadronization model. This model requires a new GENIE external dependence: PYTHIA8. Contributions by Shivesh Mandalia (QMUL).
• Addition of the Correlated Fermi Gas nuclear model.
• A native implementation of a new BSM generator, simulating the production and decay of Dark Neutrinos according to the model described in Phys. Rev. Lett. 121, 241801. Contributions by Iker de Icaza (Sussex) and Pedro Machado (FNAL). [GENIE pull request #114]
• A substantial upgrade in the native BSM generator for the simulation of Boosted Dark Matter (BDM), bringing it sync with the model described in arXiv:1812.05616. The newly deployed BDM code a) allows a broader set of particle physics models, including both vector and axial couplings, as well as different isospin structures, b) has improved modeling of the elastic scattering process, including a pseudoscalar form factor, c) includes the simulation of scattering off electrons, and d) includes anti-dark matter scattering. Contribution by Joshua Berger (Pittsburgh).
• Addition of a new and complete implementation of a CEvNS event generator. Uses an implementation of the CEvNS cross-section model of Kelly Patton, Jonathan Engel, Gail C. McLaughlin, and Nicolas Schunck described in Phys. Rev. C 86, 024612. [GENIE pull request #45]

Event generation and core framework improvements:

• Added a new toolkit to generalise and simplify the implementation of cross-section models relying on tabulated hadron tensors. The change underpinned newly developed implementation of the SuSA2 model. Old models were upgared to use the new toolkit
• Complete refactoring of the GENIE decayer and hadronization modules, upgrading decayers and hadronization modules to full-blown GENIE "event record visitors" and eliminating PYTHIA6-specific elements from GENIE interfaces. The change underpinned newly developed interfaces to PYTHIA8.

Improvements in generator tools (flux and geometry drivers, event generation and other apps):

• Added a new toolkit (EvtLib: Event Library Interface Generator) providing a file interface to external neutrino MC generators. EvtLib allows experiments to run external neutrino MC generators, re-using their existing GENIE MC production workflows and the extensive GENIE flux and geometry tools. Contribution by Chris Backhouse (UCL). [GENIE pull request #103]
• Added a new option (-T) in the GENIE atmospheric neutrino event generation app, to generate the number of corresponding to a given livetime (in sec). This is similar to the -e option in our apps for accelerator-based experiments, generating the number of events corresponding to a given data exposure unit (here, proton on target) rather than generating a fixed number of events. Contribution by Tony LaTorre (Chicago). [GENIE pull request #92]
• Automatically select flux surface radii when a detector geometry is specified in the GENIE atmospheric neutrino event generation app. Contribution by Tony LaTorre (Chicago). [GENIE issue #83] [GENIE pull request #93]
• New options installed in GMCJDriver: Options to a) always force an interaction of the input neutrino flux ray, b) use logarithmic binning in the histogram that records the maximum possible interaction probability, as a function of neutrino energy, in the current MC job, and c) change the safety factor applied in the estimated maximum interaction probabilities when rejection sampling is used. Contribution by Alfonso Garcia (NIKHEF). [GENIE pull request #75]
• Added the option to use variable bin width flux histograms in the T2K and FNAL (applicable to all FNAL experiments) specialised event generation apps. Previously, this option for histogram-based flux descriptions existed in the generic event generation app but was left out of the more specialised apps, since the power of these apps is exploited by providing detailed ntuple-based flux descriptions produced by beamline simulations. This update improves these specialised apps for users who wish to use them with simpler flux descriptions. [GENIE pull request #124]

Other improvements / bug fixes:

• Bug fix: Fix an issue with electron (anti)neutrino scattering on Helium. The Smith-Monitz model (like any other RFG model) is not applicable to Helium, and cross-section calculation code was crashing. An ad hoc solution was implemented. [GENIE pull request #107]
• Bug fix: Fixed two bugs with signs used in the Berger-Sehgal and Kuzmin-Lyubushkin-Naumov resonance models. The fix was installed for clarity and it has no effect, as the wrong signs were cancelling each other out. [GENIE pull request #107]
• Bug fix: Added code to handle P33(1600) in the GENIE event generation modules. The P33(1600) resonance (a 4-star resonance in 2019 PDG) was added in the GENIE v3 cross-section calculations but, due to missing resonance data, the resonance was ignored during event generation. In versions affected by this bug, P33(1600) is added as a "Rootino" (pseudo-particle PDG code = 0) and its decay is not simulated. [GENIE pull request #65]
• Bug fix: Fixed a mistake in BaryonResonanceDecayer::IsHandled() (returned input PDG code, as opposed to the correct boolean flag).
• Bug fix: Installed a fix in AGCharm2019 hadronizatiom model, allowing the production of charmed-mesons (D+, D_s and D0) above a previously existing cutoff value of 100 GeV. Issue reported by Emircan Elikkaya and Murat Ali Guler (METU) of the SHiP experiment. [GENIE issue #77]
• Bug fix: Fixed a mistake in a Jacobean used in the Rosenbluth cross-section calculation. The bug affects the GENIE electron scattering mode only. [GENIE pull request #121]
• The time coordinate of all particles in the event record (time increments with respect to the event vertex time) is now recorded. A new convention was introduced: The particle time increments are given in ys (yocto-seconds / 1E-24 seconds). The conventions for other relevant quantities given in the event record remained unchanged (particle position increments in fm, event vertex coordinates in SI units). [GENIE pull request #119]
• The correct space and time coordinates of the daughter particles produced in PYTHIA decays are now stored in the GENIE event record. Previously, the coordinates of the daughter particles were set to be the ones of the mother particle. [GENIE pull request #119]

Other comments:

• Now supports C++14 (previously C++98)
• Dropped support for ROOT5

Improvements over 3.0.4

• Correct handling of the hit nucleon radius during CCQE spline integration in v3.0.4. This leads to an unphysical suppression of the CCQE total cross section at low energies for all GENIE model sets that use a local Fermi gas model (the G18_10 series). Other model sets are unaffected by this issue. More details about this problem are available in a recent GENIE user forum talk (GENIE doc-db 129).
• Fix an error in the Jacobian used by the Rosenbluth EMQE cross section model. See GENIE doc-db 133.
• Various issues with EM reaction channels were fixed, e.g., a missing Jacobian in the EMRES channel. See GENIE doc-db 114 and GENIE doc-db 120.
• Very minor problems (e.g., a spurious warning message) in gntpc and gevcomp apps.

Improvements over 3.0.2

• Previously, Pauli blocking for quasielastic event was implemented as a suppression factor which was computed analytically. The calculation was valid only for a Fermi Gas model. Pauli blocking is now implemented in a more generic way, as a cut on the outgoing nucleon momentum, allowing for correct calculation of the effect irrespectively of the assumed nucleon momentum distribution.
• Bug fix: Removal energy was ignored by the quasielastic event generator, which always put the struck nucleon on the mass shell.
• Bug fix: In the GENIE implementation of the Valenia model, an incorrect reference frame was used to compute the contraction of the leptonic and hadronic tensors.
• Bug fix: In the GENIE implementation of the Valenia model, a Coulomb correction was implemented only as an overall scaling factor in the differential correction, an ignored the effect on the 3-momentum transfer.
• Bug fix: In the quasielastic event generation, there was a single instance of Q² miscalculation due to a mismatch of the reference frames of the neutrino and final-state primary lepton momentum 4-vectors.
• Bug fix: In the GENIE implementation of the Valenia model, in the calculation of the Coulomb correction through an integral over the nuclear volume, integration limits did not account for the A^1/3 grow of the nuclear radius, resulting in a correction that was too small for heavy nuclei.
• Bug fix: In the GENIE implementation of the Valenia model, explicit forms of the hadron tensors should be evaluated in the lab frame with coordinates rotated so that the Coulomb-corrected 3-momentum transfer points along the positive z direction. Previously, the Coulomb correction was not applied in the edge case where the uncorrected 3-momentum transfer was pointing along the negative z direction.
• Bug fix: Previously, in the new quasielastic event generator first included in v3, Fermi motion was erroneously applied to free nucleon targets.
• Bug fix: Previously, Pauli blocking was erroneously applied in the simulation of quasielastic charm production.
• Bug fix: In the simulation of the Δ → N + π decay, the polar angle θ was defined wrt to the z axis, rather than wrt to the direction of the momentum-transfer vector in the Δ CM frame.
• Bug fix: The invariant mass threshold for deep-inelastic events was inadvertently set to the nucleon mass, when the corresponding threshold for resonance events was modified to allow simulation of Δ → N + π decays below the pion production threshold. The threshold for deep-inelastic events is now set back to the sum of the nucleon and pion masses.

Detailed technical note to be find at the GENIE Document Database: GENIE doc-db 113.

Improvements over 3.0.0

We are pleased to announce a major new release, the first in more than a decade, and the start of the Bear series.

Release v3.0.0 consolidates a series of physics modelling improvements installed over the past 5 years. It also represents a major shift in philosophy: Instead of a single "Default" model with optional modelling elements that can be enabled by users, at own risk, GENIE now constructs, deploys and supports multiple comprehensive model configurations that run out the box. Special care was taken to combine models in a way that consistency is ensured, double-counting is removed, and updated model parameter estimations are made to take into account the impact of experimental constraints on the specific mixture of models in each given configuration. Full characterization of comprehensive models and tunes is performed using detailed data/MC comparisons.

Between 2015-2018, GENIE implemented a powerfull new global analysis of neutrino scattering data. The analysis relies on the Comparisons product, which includes extensive curated archives of neutrino, charged-lepton and hadron scattering data, as well as highly-developed software to produce a comprehensive set of data/MC comparisons. Comparisons includes interfaces to the Professor tuning tool which "reduces the exponentially expensive process of brute-force tuning to a scaling closer to a power law in the number of parameters and allows for massive parallelisation". This enabled the generation of several new tunes, a selection of which was fully integrated in the Generator product and was made available in GENIE v3.0.0 (see here for the current list of publicly available tunes). Nuclear cross-section and hadronization tunes are ongoing and additional tunes will be made available in future revisions.

The new release constitutes a major technical upgrade, with important modifications in the core framework, in particular the configuration system, and a re-organization of the entire source tree. Please also note that from v3.0.0, Reweight is distributed as a separate product in the family of the GENIE products that also includes the Generator, Comparisons, and Tuning products.

Details for GENIE v3.0.0 and its new tunes will be made available in a near-future publications.

Improvements over 2.12.8

Physics changes:

• `EmpiricalMEC-FracPN_NC`, `EmpiricalMEC-FracPN_CC` now directly specify the NP pair fraction, instead of being multiplied by another factor.
• `EffectiveSF` no longer crashes when running on nucleons.

FSI development model updates (not part of the default physics model):

• Save FSI model used (Intranuke2015) so that it can be cut on later.
• Add suppression for low energy proton-proton collisions due to Coulomb interaction (hA2015, hN2015).
• Disable binding energy corrections for low energy hadrons (caused a lot of errors) (hA2015, hN2015).
• Add empirical cutoff for protons, neutrons at ~30 MeV (hN2015, A dependent) to suppressi events where all nucleons are emitted (temporary fix to hN2015).
• Disable proton/neutron elastic scattering (hA2015).

Non-physics changes:

• Improve the automatic detection of dependencies in the configure script.
• Reorder library list for Apps (put low level libs first) for Mac OS X `bind_at_load`.
• Applications using `genie::utils::app_init::XSecTable(inpfile)` now search `$GXMLPATH` for spline files ins the same way config XML files are found.
• Resolve speed issues with `QELEventGenerator` from 2.12.8.
• Adjust `NievesQE` code so that `max_xsec` is correct for more than 1 nucleus in a simulation.

Improvements over 2.12.6

Physics changes:

• Added nucleon-nucleon correlation data to `data/evgen/nncorr`.

Non-physics changes:

• Fixed a bug in variable initialization in `GBGLRSAtmoFlux.cxx` pointed out by the community (T. Yang).
• Bug fix to properly write `Q2s` and `Ws` to the ntuple in the NSV MEC model.
• Fixed a bug in `QELEventGenerator` in calculating the Max Xsec with energy/nucleus/flavour dependence. (Model is very slow though, so be careful.)

Improvements over 2.12.4

Physics changes:

• Added Helium in the Valencia (NSV) MEC model, to be generated using the Carbon hadron tensor and the regular scaling function. Also we now let the code go down to Be9, a default GENIE isotope.
• Activated lines in pdg table for two pseudonuclei made of pp and nn, so that generation on Helium can proceed but didn't activate (kept commented out) the decay modes (must be handled in code directly).

Non-physics changes:

• Added new event generator lists: CCinclMEC+NueEl, duplicated Default+MEC as Default+CCMEC to avoid ambiguity, and added Default+CCMEC+NCMEC.
• Fixed a bug in variable initialization in `GFLUKAAtmoFlux.cxx` pointed out by the community (Tao Lin).M/li>
• Fixed a bug in the Valencia (NSV) MEC model in the scaling function that affected calculation for the neutrino case. The bug only affects nuclei scaled away from a hadtensor. There was no effect on C, O, Ca40, Pb.
• Fixed a bug in the Valencia (NSV) MEC model that set a too-low XSecMax for O and maybe N14. The XSecMax has been increased to be more safe.
• Bugfix: The use of NucBindE was disabled in the Valencia (NSV) MEC model for 2p2h in 2.12. Therefore, we now add the resulting removal energy directly to the remnant nucleus.

Improvements over 2.12.2

Physics changes:

• Add Oset implementation in hA2015, readjust for piA data validation. Remove elastic scattering in hA2015.
• Add NN medium effects from Pandharipande/Pieper model to hN2015 FSI model. Use lookup tables to improve speed.
• Add nn total cross section data to Intranuke.

Non-physics changes:

• Fix a bug that caused unnecessary warning spew when computing cross section for pions with kinetic energy over 1 GeV in the BergerSehgalFMCohPi model - now use Rein-Sehgal formulation more explicitly in that case. This is very close to what we were doing before, but somewhat awkwardly. Additionally, the old effective switch-over was for a pion kinetic energy less than 1 GeV (by the pion mass) rather than at 1 GeV.
• The gevgen app now accepts a command line argument to specify the output file name.
• Fix a bug that caused 'make install' to not work properly.
• gMakeSplines: Add optional --no-copy argument to disable adding the input cross-sections in the output file. Default behavior is unchanged.
• Updated Minerva's beampos value to match their code.
• Fixed a bug that causes that floats to be sometimes printed in hexadecimal format in C++11.
• Recovered a lost patch to the Makefiles (present in 2-10-10, but lost in 2-12-0 and 2-12-2) that was needed to make ROOT6 work with the Fermilab art framework.

Improvements over 2.12.0

Non-physics changes:

• Move z-expansion entries in EGSyst enum at the back of the list so as not to reshuffle the subsequent values and invalidate stored reweights that are ordered by the old enum values.
• Add SingleKaon library to the set loaded by the genie-config script.
• Name for TGraph of strange cross sections in root files include _strange

Improvements over 2.10:

Non-physics changes:

• Improved performance with ROOT 6.

Physics changes - new/improved physics models:

• Valencia MEC (Nieves, Simo, Vicente Vacas, PRC 83 (2011) 045501 Schwer, Cherdack, Gran, arXiv 1601.02038)
• Local Fermi Gas nuclear model
• Nieves CCQE (Nieves et al, PRC 79 (2004) 055503)
• Oset cascade in hN (Oset et al, Nucl. Phys. A468 (1987), Oset et al, Nucl. Phys. A484 (1998))
• K+ FSI in hN (see upcoming e-print)
• neutron-antineutron oscillations
• z-expansion of the axial form factor (Bhattacharya, Hill, Paz PRD 84 (2011) 073006 and Meyer, Betancourt, Gran, Hill arXiv 1603.03048)
• Several small tweaks to the resonance model (delta decays are no longer isotropic and the cross section for delta to N gamm was improved; see upcoming e-print)
• QEL hyperon production (A. Pais, Annals Phys. 63 (1971) 361)
• Berger-Sehgal coherent pion model (Berger, Sehgal PRD 79 (2009) 053003)
• Rein diffractive pion production model
• Bug fixes to the Bodek-Yang model (not applied by default)
• Energy dependent MA model (K. Kuzmin and V. Naumov, in press (2016))
• Added more functionality to the effective MEC model (7 new parameters to select do-nucleon initial state (CC nu/nubar, NC), perform integration for NC events, and provide reweighing knob for initial state dinucleon selection, see upcoming e-print).
• Numerous updates to the nucleon decay modes.

Event generation apps

• Patch to `gevgen` for handling input flux histograms with variable-width binning.

Flux and geometry drivers

• Installed the Honda, Athar, Kajita, Kasahara, and Midorikawa (HAKKM) atmospheric flux driver (GHAKKMAtmoFlux). Previously installed atmospheric fluxes were renamed (GBartolAtmoFlux -> GBGLRSAtmoFlux, GFlukaAtmo3DFlux -> GFLUKAAtmoFlux). The \phi dependence of atmospheric fluxes was installed generically at the GAtmoFlux base class (only available through HAKKM). All three fluxes available in the gevgen_atmo event generation app.

Improvements over 2.10.8:

Non-physics changes:

• Final State Interaction (FSI) model bugifx - The model used to make unguarded checks in some circumstances on the probe type during FSI computations, but the probe isn't defined for nucleon decay models. So, in these cases, we would access a null pointer and create undefined behavior. That is now fixed.
• The Interaction package was patched to add an explicit streamer for `std::map` which is required for reading back kinematics with newer versions of ROOT.
• Change in KineVar map streamer means `Kinematics` ClassDef need to be bumped to version 2.
• When using ROOT 6, writing TTree branch `NtpMCEventRecord` refuses to be split, so don't event try (for now - will be revisited)
• When generating ROOT 6 dictionary generate .rootmap file and regularize .pcm file name to match library name.
• Minor fixes to header guards and to eliminate pedantic warnings.

Physics changes:

• None.

Improvements over 2.10.6:

Non-physics changes:

• GENIE 2.10.8 contains patches to support ROOT5 and ROOT6 concurrently. There are no other changes.
• One important point users need to be aware about with this release is the name of the GENIE Cint macro. One of the requirements of the new ROOT 6 compiled macros is that a function can't have the same name as a namespace any more. That means the macro can no longer be called just "genie.C" - we've renamed it "genie_setup.C". This breaks backwards compatibility with any scripts that load GENIE libraries by running this macro. The executable that runs an interpreter session is still named "genie".

Physics changes:

• None.

Improvements over 2.10.4:

Non-physics changes:

• None.

Physics changes:

• The MECPXSec cross section (for the Dytman model) is no longer forced to zero at 5 GeV. That functionality was taken out, although sufficient comments remain in the code to re-enable it by hand.
• Also for Dytman MEC, the n+n and n+p fractions were swapped for the initial state target in neutrino mode (now n+p targets are more likely). Antineutrino mode was not changed.
• New parameters were added to UserPhysicsOptions.xml to control the n+p fraction in addition to other parameters of the Dytman MECPXSec model.

Improvements over 2.10.2:

Non-physics changes:

• Add Tomasz Golan (Rochester) and Julia Yarba (Fermilab) to the logo - welcome to GENIE!
• Update copyright messages to 2016.
• Fix fZ0 data member shadowing bug in src/FluxDrivers/GSimpleNtpFlux, and make associated modifications to GNuMIFlux and GFluxFileConfigI.
• Add debug output tweaks to src/support/fnal/EvGen/gFNALExptEvGen.cxx; no functional change.
• Update NOvA locations transformation in src/FluxDrivers/GNuMINtuple/GNuMIFlux.xml.

Physics changes:

• none.

Improvements over 2.10.0:

Non-physics changes:

• Add Libo Jiang and Jeremy Wolcott to the logo - welcome to GENIE!
• Bug fix in FluxDrivers/GFlavorMap.cxx: Fix test string.find() == 0 and do some string trimming as well.
• Expand file path (e.g. ~ or environment variable) of xsec file before further processing in Utils/AppInit.cxx.
• Add a feature to the Utils/GSimFiles class - save the path to the XML file and introduce corresponding access method.
• Allow override of default PDG file with environment variable: ${GENIE_PDG_TABLE}

Physics changes:

• Added nuclei to the default PDG table for Nova.
• Bugifx in src/MEC/MECGenerator.cxx: catch bad phase space decay events.
• Stop photon rescattering in HadronTransport/Intranuke2014.cxx and HadronTransport/Intranuke.cxx.

Improvements over 2.8.6:

GENIE 2.10.0 is a production release.

Non-physics changes:

• The XclsTag object was updated with a new field for strange production for one of the new models in 2.10.0. This could impact the ability of some users to read older GENIE files.
• GSL (GNU Scientific Library) is now used by default by the cross section integration routines and is a required library. We have re-tuned the parameters for producing DIS cross section splines to reflect the usage of GSL. This stabilizes a number of the "wiggles" seen in release candidate 2.9.0.

Physics changes:

• Effective Spectral Function model from Bodek, Christy, and Coopersmith (EPJC (2014) 74:3091) is now available as an optional model.
• Very high energy mode extension to 5 TeV.
• Inclusive Eta production is included.
• The Berger-Sehgal resonant pion model (PRD 76, 113004) with MiniBooNE tuning (by J. Nowak) is now available as an optional model.
• Improved hA FSI model.
• Single kaon production from Alam, Simo, Athar, and Vacas (PRD 82, 033001 (2010)) is now available as an optional model.
• Implemented a GFluxDriverFactory, where flux drivers can self-register and be returned by name.
• Introduced two common flux interfaces GFluxExposureI and GFluxFileConfigI, allowing GNuMIFlux, GSimpleNtpFlux and the external GDk2NuFlux to be used interchangeably. Other flux drivers can start to incorporate these.
• Renamed gevgen_numi executable to gevgen_fnal to emphasize its use in FNAL experiments at other beam lines (e.g. Dune); executable will dynamically pick up GDk2NuFlux flux driver if available (i.e. no longer a build dependence). Flux entries from the input driver will be copied to a branch along side the GHepRecord; flux metadata from all ntuple files will be copied to the output file.
• Reinstated method in GHepRecord to return the stored KinePhaseSpace_t, allowing records to be fully recreated from elements stored in non-genie formats.
• Numerous small updates to the validation packages.

Notable bug fixes. Please note, we attempt to give credit for all the changes we can, but we sometimes miss things when we review the commit history - if you see an omission, please let us know!

• NC Elastic sign error discovered by L. Alvarez-Ruso.
• Remove explicit ".so" from loadlibs.C so ROOT's library loading mechanisms also work on Mac OS-X.
• Small bugfixes to the Kuzmin-Lyubushkin-Naumov model in the Berger-Sehgal resonance model by I. Kakorin.
• Close the directory opened by LHAPDF when getting PDF sets, from M. Nirkko.
• Message thresholds may be specified in an ordered list of files so they may be cascaded.
• Fix parameter indexing issue when defining a "box" fiducial volume. Also include option for using Geo/GeomVolSelectorRockBox as a volume limiter (this is an extension and changes no previous behaviour).
• Fix small bug in the Registry::Get() method.
• Set fZmin and max to be largest and smallest possible in Numerical/BLI2D, from R. Gran.
• Call Max instead of Min when trying to get a maximum in Numerical/BLI2D, from J. Schwehr
• Re-weighting bug discovered by NOvA in the Coherent model.
• Re-weighting bug discovered by Minerva in the Delta model (to non-isotropic, weights were not applied to anything but delta++).
• Re-weighting fix for formation zones.

Improvements over 2.8.4:

Non-physics changes:

• This release is almost identical to 2.8.4 with the only change being in how the $LHAPATH environment variable is handled and how the patched GRV98lo file is distributed.

  We removed the restriction on $LHAPATH. We now supply, in $GENIE/data/evgen/pdfs, the patched PDF. Please copy this to your $LHAPATH area. Note the PDF has a different name - it is GRV98lo_patched.LHgrid. This changed name is reflected in $GENIE/config/PDFLIB.xml. By default, GENIE will not run if you do not copy the patched PDF file to that area. If you would like to use the older, un-patched PDF, simply rename the PDF in the configuration XML to drop the _patched part of the filename.

Improvements over 2.8.2:

Non-physics changes:

• Fixed a bug in make install (introduced in 2.8.2). It did not previously run install on the Conventions package. (P. Rodrigues, MINERvA; rev r4219)
• Update GNuMIFlux.xml for Minerva flux window size and add preliminary LBNE transformations (R. Hatcher; rev r4221)
• Support for Dk2Nu in gevgen_numi (src/support/numi/EvGen/gNuMIExptEvGen.cxx); build instructions can be found here.
• Fixed a bug (introduced in 2.8.2) in PDF/PDFLIB.cxx that could create situation where one eventually run out of file handles checking the LHAPATH. (P. Rodrigues, MINERvA; rev r4224)
• Added support to GNuMIFlux for Minerva variant of g4numi format ntuples; additions should be compatible with older file layouts as well; bump ClassDef version of associated GNuMIFluxPassThroughInfo. (R. Hatcher; rev r4225)
• Update GNuMIFlux.xml with new NOvA NearDet coordinate transformation (R. Hatcher; rev r4227)
• Add NOvA rock configurations to GNuMIFlux.xml, remove old unnecessary configs and clean up some misleading comments (R. Hatcher; rev r4229)

Improvements over 2.8.0:

Non-physics changes:

• Bug fix in the event generator driver. (MCJDriver). (J. Koskinen, Ice Cube)
• Bug fix in the beam line flux driver. (T. Dealtry, T2K)
• Performance improvement for the re-weighting initialization code. (C. Backhouse, NOvA)
• Intranuke: additional validation data sets, new validation programs. (S. Dytman, N. Geary and T. Golan)
• Makefiles: stop the build on an error. (P. Rodrigues, MINERvA)
• Add support for Dk2Nu flux format files. (R. Hatcher)

Physics model changes:

• Bug fix in the coherent pion model (fencepost error in the indexing code for looking up the pion-nucleus cross section). (H. Gallagher, D. Cherdack, and D. Scully)
• Intranuke changes: (S. Dytman)
  • Fix problem with high energy protons failing and causing program to delay,
  • Fix confusing names for absorption final state.
  • Fix strangeness conservation problem in kaon absorption.
• PDF overhaul (H. Gallagher and G. Perdue)

  We recommend using LHAPDF5 and not Cernlib for PDFs. There is a bug in the version of GRV98lo that comes with LHAPDF5. We contacted the LHAPDF authors and they immediately provided a fixed file, but it must be distributed with GENIE as LHAPDF5 is frozen. The PDF set included here was producted by Graeme Watt (Durham, UK). The patched version recreates exactly: grv98.f

  NOTE: In this version of GENIE, you MUST use the PDFs in $GENIE/data/evgen/pdfs with LHAPDF5. You MUST set your LHAPATH environemnt variable to $GENIE/data/evgen/pdfs!

  Our thanks to Graeme and LHAPDF for the patched file. Please note that this file will work only with LHAPDF 5.x and is not properly formatted for LHAPDF 6.

• Nuclear modification to structure functions is now f(x), not f(rescaled x). (B. Tice, MINERvA/SeaQuest)
• Bug fix in the formation zones calculation for nucleons (H. Gallagher)

  Prior versions of the GENIE implementation of the formation zone underestimated it for nucleons. The problem is summarized in Section IV, and in particular Figure 8 of this paper.

Improvements over 2.6.0:

New interaction processes:

• First implementation of a meson exchange current (MEC) event generator. The CC MEC generator simulates CCQE-like scattering off nucleon clusters and is tuned to the CCQE-like rate difference between the MiniBooNE data and the nominal CCQE expectation based on bubble chamber measurements on deuterium.
• Implemented inverse muon decay (IMD) annihilation channel v̄_e e^- → μ^- v̄_μ. Before, only v_μ e^- → μ^- v_e was implemented. New code was contributed by Rosen Matev, Roumen Tsenov et al.

Improvements in hadronic simulations:

• Major INTRANUKE code restructuring and deployment of an experimental version of the new hN INC model.
• INTRANUKE particle stepping changes / additions: π^-,π⁺ and n,p cross-section differences are taken into account. The isospin of nuclear medium is treated properly.
• INTRANUKE hA addition: More complete modeling of pion absorption and nucleon knockout processes based on a parameterization of the hN model. The number of produced nucleons is chosen from a distribution, then a phase space decay is used to set the nucleon kinematics.
• INTRANUKE hA addition: Inelastic reactions now treated as quasielastic. Angle chosen from 2-body kinematics, includes binding energy and Fermi motion. Pauli blocking is included.
• INTRANUKE hA addition: Pion production modeling now closer to data. Use compilation of data and fits for πN→ππN and for NN→πNN. Kinematics generated vis phase space decays. User has choice of including the effect of further intranuclear rescattering on intranuclear rescattering products at the expense of reweighting unitarity (for currently available reweighting algorithm).
• INTRANUKE hA addition: Kaon rescattering

Event generation apps, neutrino fluxes and geometry drivers:

• Added nucleon-decay event generation application. Nuclear effects are simulated using the same models used for neutrino scattering. The following decay modes are simulated: p → e⁺ π⁰, p → μ⁺ π⁰, p → e⁺ η⁰, p → μ⁺ η⁰, p → e⁺ ρ⁰, p → μ⁺ ρ⁰, p → e⁺ ω⁰, p → μ⁺ ω⁰, n → e⁺ π^-, n → μ⁺ π^- and p → v̄ K⁺.
• Overhaul of the GENIE FLUKA and BGLRS atmospheric neutrino flux drivers (contributed by Andy Blake). The status of these drivers is now upgraded from experimental to production.
• Updates to the NuMI flux driver: Allow for non-random initial entry. Correct POT accumulation in case of flavor rejection and/or in case the flux is used for geometry exploration. Allow vector of file patterns to be passed to the driver.
• Allow geometry exploration with rays of maximum neutrino energy.
• Additional support for PathLengthList manipulation and error handling in event generation drivers.
• Additional support for GFlavorMixerI derived classes.

Data archives, validation, tuning & reweighting apps:

• Updated and re-organised the extensive neutrino-, electron- and hadron-nucleus scattering data archive used for physics validation and tuning. The new data archives are stored in $GENIE/data/validation
• Updated and re-organised the suite of validation and tuning programs.
• Event reweighting updates bring the reweighting in sync with the latest INTRANUKE hA developments.

Configuration and build system and other technical aspects:

• GENIE environmental variables ($GSEED, $GSPLOAD, $GEVGL, $GMSGCONF, $GCACHEFILE, $GUNPHYSMASK, $GMCJMONREFRESH, $GHEPPRINTLEVEL, $GPRODMODE, $GDISABLECACHING) may no longer used. Corresponding command-line arguments were added in all GENIE applications.

Bug-fixes:

In addition, v2.8.0 includes all bug-fixes and new features also installed in 2.6.2, 2.6.4, 2.6.6 and 2.6.8 revisions (see below).

This is a patch release including small fixes kindly provided by Brett Viren, Dimitris Lennis and Tarak Thakore so that GENIE builds against ROOT 5.34/03 with GCC 4.3.2 and on Ubuntu 12.*.

This is a patch release issued in preparation for T2K MC production 5, which allows the T2K flux driver and event generation application to handle the 4-fold size increase of the combined input JPARC flux simulation n-tuples.

This is a patch release issued in preparation for the new T2K sand muon geometry and flux (nd13). The JPARC neutrino flux driver was trivially extended to handle a larger number of near detector locations (up to 50; was up to 10).

Improvements over 2.6.0:

• Bug-fix: Transition from KNO to Pythia6 (W range from 2.3 to 3.0 GeV) in AGKY was reversed (reported by Torben Ferber).
• Bug-fix: Change the way the top volume name is matched in ROOT geometry navigation code. Previously the string length was not required to be same and sometimes led to degeneracies and selection of incorrect top volume (reported by Kevin Connolly).
• Bug-fix: The atmospheric flux driver was not generating flux vertices uniformly (per unit area) in the plane which is perpendicular to the flux neutrino direction (reported by Torben Ferber).
• Bug-fix: T2K flux driver was ignoring decay modes added in JNUBEAM version 10a (numu from K+ and K0, numubar from K- and K0, nue from pi+, nuebar from pi-).
• Speed optimizations when generating events over complex detector geometries with neutrinos drawn from beam-line simulation ntuples. Dramatic speed increases of 1-2 orders of magnitude can be achieved for event generation over complex geometries (approaching speed of event generation for single nuclear targets). Changes to the flux interface and GMCJDriver. Currently only the T2K-specific event generation app employs the optimized scheme.
• Improvement to reweighting tools (brings them in line with those used for evaluating GENIE systematics in the 2010a T2K analysis).
• T2K event generation application: Add option to pre-calculate event generation probabilities for all neutrinos in the input flux ntuple. Print out of exact event rate predictions, for use when deciding how many events to put in a spill/bunch later in T2K MC chain.
• T2K flux driver updates: Pass-through information includes all new variables in most recent 11a JNUBEAM T2K flux files. Ability to handle much larger flux files. Implement flux interface extension required for speed optimization.
• Geometry package: New classes GeomVolSelectorFiducial and GeomVolSelectorRockBox (see class documentation).
• Flux package: New classes GFlavorMixerI, GFluxBlender (see class documentation). Added SetUserCoordSystem(TRotation &) in atmospheric flux driver to set rotation between the topocentric horizontal and a user-defined detector coordinate system.
• Installed new atmospheric neutrino event generation application (gevgen_atmo). See $GENIE/src/support/atmo/EvGen/.
• Installed new event reweighting application (grwght1scan). See $GENIE/src/support/rwght/.

Improvements over 2.4.0:

• Included all bug-fixes and new features also installed in 2.4.2 and 2.4.4 revisions (see below).
• Added electron-nucleon/nucleus scattering simulation capabilities. Now can validate GENIE against electron scattering data using the exact same phyhsics framework that simulates neutrino interactions.
• Significant extension of the GENIE event reweighting capabilities.
• Collected & released many of the GENIE physics validation and model fitting tools.
• AGKY hadronization: Improvements in strange particle production.
• Added interface to LHAPDF - Note change in GENIE dependencies (We recommend using the light-weight LHAPDF library and scrapping CERNLIB)
• Users now have very fine control over which particles to decay and which decay modes to inhibit.
• Geometry navigation: Significantly improved performance (ROOT geometries).
• Geometry navigation: Added capability to define arbitrary fiducial volume cuts.
• JPARC neutrino flux driver: Certified with version 10a fluxes and included additional flux pass-through info. Maintained compatibility with 07a fluxes.
• NuMI flux driver: Numerous improvements. FLUGG support.
• Improvements of atmospheric flux drivers.
• Installed new generic ntuple flux driver
• Updated the `t2k_rootracker', `numi_rootracker' bare-ROOT event formats and the `t2k_tracker' SuperK text event format following communication with relevant detector and analysis groups.
• Added first experimental version of a diffractive scattering generator.
• Interfaced GENIE with GNU Scientific Library to access advanced multi-dimensional integration algorithms (experimental).
• Updated for use with the latest gcc and in 64-bit platforms.

This is a A minor 2.4 revision primarily to support early-summer physics MC production plans (T2K/MDC1) while 2.6.0 is in the works.

• Bug-fix: Corrected Adler's PCAC CC suppression term in the coherent pion production model (mpi -> mpi^2)
• Bug-fix: Corrected pion kinematics in coherent pion production scattering (the transverse momentum randomization in the LAB^{prime} frame, z^{prime} is along \ver{q}, and the rotation from LAB^{prime} to LAB were taking place in reversed order).
• Bug-fix: Fixed problem with density-weighted path-lengths in the ROOT geometry navigation code.
• Bug-fix: Fixed problem with PYTHIA decay-products entering the GHEP record with different position 4-vector units than expected.
• Bug-fix: Fixed a minor problem with the search for the maximum coherent differential cross section, which was preventing coherent pion event kinematics from being generated for energies very close to the energy threshold.
• Requested feature: As per popular request, GENIE won't decay pi0's by default. If you need to restore the previous behaviour then toggle the `InhibitPi0Decay' flag.
• Requested feature: Tweaked the JPARC flux driver and the T2K event generation application to allow event generation for specific neutrino flavours only.
• Requested feature: Added option to generate events in specific geometry volumes only.
• Requested feature: Addded tool to generate NEUT-like cross section table for SK MC job normalization.
• Other: Updated Ar40 removal energy as per ArgoNEUT request. Updated the PDG table. Added snapshot of the NuMI flux driver (as of the v2.4.4 tagging date) for test runs by the NuMI expts. Backported a version of gntpc that includes the implementation of the `numi_rootracker' bare-ROOT format. Backported improvements to the gntpc code generating summary ntuples.

This is a A minor 2.4 revision primarily to support MDC0 T2K/SuperK production plans.

• Bug-fix: Fixed wrong Delta- code, affecting the Delta- decays and the produced final states in nubar RES events
• New feature: Finalized/extended the 't2k_tracker' format and the mapping to NEUT reaction codes.

Improvements over 2.2.*:

• Significant speed improvements (event generation ~ x3 faster than 2.2.2 for event generation for fixed initial state. ~ x1E+2 faster for event generation on ROOT geometries).
• Fixed a few remaining memory leaks.
• Installed new customized event generation application for T2K (gT2Kevgen, see $GENIE/src/support/t2k/EvGen) including a driver for the JPARC neutrino flux and hooks for the nd280, 2km, ingrid and SuperK detector geometries and/or nuclear target mix.
• Added event converter from GENIE's native GHEP format to T2K/nd280's ROOT-only format (rootracker)
• Added simulation of nuclear de-excitation gamma rays for O16.
• Added a preliminary implementation of anomaly mediated neutrino - photon interactions [Harvey, Hill and Hill, PRL99,261601(2007)]
• Added the V.Tvaskis et al. (PRL 98, 142301, 2007) parameterization of the longitudinal to transverse cross section ratio R as an alternative to the existing Whitlow parameterization.
• More carefull treatment of thresholds in the cross section splines.
• Bug fixes in algorithm navigating ROOT-based detector geometry descriptions.
• Added a flux driver for the Bartol atmospheric neutrino flux.
• The code reading the input XML cross section files has been switched from the tree-based libxml2 API to the XmlTextReader libxml2 API. Hugely better speed/memory performance when using large XML cross section files (eg ~100MB as when using all nuclear targers on nd280 & MINOS geometries). Requires libxml2 version ≥ 2.5.0
• Configuration script changes.

A minor 2.2 revision:

• Updates the code converting events from the native GHEP/ROOT format to the tracker format used by T2K to better match what is expected by the T2K/nd280 detector mc.

Improvements over 2.0.*:

• Changes to the determination of the mean free path of hadrons in nuclear matter in INTRANUKE / hA model (gDocDB-760)
• Intranuclear vertex selection uses a realistic nuclear density profile.
• Added QE charm production (gDocDB-759) using the cross section model of S.G.Kovalenko, Sov.J.Nucl.Phys.52:934 (1990)
• Added elastic ve- scattering.
• Added GENIE tcp/ip event server for interfacing with legacy (fortran) MINOS detector MC (gminos)
• Added a cross section model re-weighting engine
• Added option to simulate multi-nucleon emission from N-N correlations (not fully developed yet and not enabled by default)
• Added a few modifications / flags so as to handle newer version of log4cpp and gcc versions > 4.1 and 64-bit systems.

The first GENIE production release (Auk).
The default physics in 2.0.0 is identical with the neugen/'daikon+' version (daikon+ is a bug fix revision of the MC used at the 2007 MINOS CC Analysis). A description of the physics model (cross section, hadronization and intranuclear rescattering can be found in gDocDB-756, 757 and 758). Various plots illustrating the GENIE-2.0.0 - neugen/daikon+ equivalence can be found in (gDocDB-755 [pub]). GENIE 2.0.0 supersedes neugen & future major model improvements will only be included in GENIE.