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Release and project report
Announced that e19 builds are being dropped as of next release (after this week)
Robert Hatcher: Recent changes to nugen and nusimdata
In preparation for Genie v3.02.00
New features in Genie v3.02.00
Event library interface from Chris Backhouse
Essentially, an interface to alternate generator, where result is then treated as Genie event
Leverages Genie interface for geometry and flux driver
New comprehensive Model Configurations and tunes
CMC list provided
More models beyond these, not all of which are incorporated in sanctioned CMCs
Tunes: re-fits with data
eg, G18_10a_02_11a is deprecated in favor of G18_10a_02_11b
A few changes impact nugen and nusimdata
Some breaking API / encoding changes. [Later clarified that no user-facing interfaces change]
PDG code for resonances updated to new std encoding (per 2019?)
Example provided
Could impact users looking at event record rather than enum code
Also if using old files against newer PDG data table to look up names
Neither likely to be a common problem for people because it involves an unusual workflow
IsCoherent
Interface change
Addition to Genie XclsTag clalss (carried over to nusimdata GTruth)
New code versions should be ok with old data, but not necessarily the reverse
Need for later (post-tune determination) filling of PDG data table
No impact to users.
Background info: Genie's units and use of time
Genie interaction Vertex 4-position (meters, seconds)
T includes time from flux window to interaction point, and from any time given by flux driver (ie, proton-on-target to flux window)
the latter is non-zero for dk2nu and new versions of gsimple
Illustrated
Flux driver time from proton
Genie from flux window
Particles in the event record: distance in fm, (new) time in yoctoseconds (10^-24))
Distance is relative to nucleus at interaction vertex
T was never set, even for delayed decays
Now propagation times and decay times are recorded
So decayed particles are offset in time and space
Showed example event record dump showing times and distances
NuGen / NuSimData MCTruth's use of time
MCTruth units (cm, ns)
Genie Vertex.T() was ignored. Now optionally considered (default off)
Controlled by GENIEHelper fcl param AddGenieVtxTime
If including proton-on-target to interaction point, one may need to adjust overall global time offset to make data and MC overlay again
If new feature is on, then people using GlobalTimeOffset need to be aware of this change so as to avoid double counting time. The GlobalTimeOffset is a fixed value. Does not change event to event
No changes to experiment code is necessary
Illustration of GlobalTimeOffset
Trajectory position of particles with status code !=0 & !=1 was previously "funky" (ie, treated in inconsistent manner)
Not converted to lab (cm) frame -- remained in fm (unnecessarily)
True info is also in GVtx variable, so no need for special handling to recover Genie event record
Now all trajectory points in cm. Breaking, but few is any should care if using the above workaround
Illustrated times
GENIE2ART::FillMCTRuth allowed specifying offset -- though no one should have been using this
Used to injet "beam structure"
Position was meant eventually for randomizing geometry-less interactions in a far detector
Units were unclear. Now MCTruth units (cm, ns)
Discussion
Timeline?
Paper on new features out by end of May (current target)
v3.02 scheduled to be out on about the same timescale, so May or June. Possibly July if something slips
Noted that these changes to nugen and nusimdata can go in right away. Do not need to wait for Genie v3.02 release
Krzysztof Genser
[a technical question that I did not follow...]
Handling of tau decays?
Working on this separately. Generalized for charm. Working on same scheme for LArSoft and edep-sim. Just need to construct a scheme to ensure proper library is loaded to allow this to be enabled
Integration to LArSoft is essentially there, but not fully tested. The way to pull in the code is not in a good state. But library just needs to get loaded to make it into the physics list. Do not have a means to optionally do this that is "pretty". Right now just a module that does this.
Prospects for porting this back to Geant proper?
for LArSoft use, should be straight forward. Needs testing to make sure get right behavior. And ensure proper linkage
Logistics?
Branches in Redmine repos for nugen and nusimdata
Interface changes are embedded in code that is not user facing
One feature, AddGenieVtxTime, SBN/SBND want to get this time variation accounted for.
Gianluca has a redmine ticket about this, and is interested in the solution.
Making available would allow him to play with it.
Likely to be an early adopter
Lynn Garren: as soon as this week's release is done, then will make a test release using the new newgen / nusimdata
Needs branch names.
Robert will update slides with that, and send the names to Lynn and Erica
feature/rhatcher_genie_30200 on nugen and nusimdata repositories