CRPA 1p1h implementation

[sjdolan]

This is a pull request for an implementation of the HF-CRPA model in GENIE. An overview of the model implementation is available in Phys. Rev. D 106, 073001. From a code perspective, this is an extension of the SuSAv2QE hadron-tensor based cross-section calculation to accept a user-defined configuration to use tensors calculated from any of:

• HF-CRPA
• Pure HF
• HF-CRPA with a plane wave (PWIA) treatment of outgoing nucleon (this is unphysical, but useful for understanding the model contents and potentially for calculating systematic uncertainties)
• HF with a PW treatment of the outgoing nucleon (with the same caveat as above)
• A slightly modified version of SuSAv2 tensors

The option is available to blend the CRPA tensors with the modified SuSAv2 tensors at large values of momentum transfer for a better treatment of regions of kinematic phase space were a relativistic treatment is required (this is the recommended use of the model). The blending scheme is detailed in the aforementioned paper. WIth this in mind, the full list of QE hadron tensor model configurations available are:

SuSAv2,
CRPA,
HF,
CRPASuSAv2Hybrid,
HFSuSAv2Hybrid,
CRPAPW,
HFPW,
CRPAPWSuSAv2Hybrid,
HFPWSuSAv2Hybrid,
SuSAv2Blend

These are selected via ModelConfiguration.xml by doing for example:

<param type="alg" name="XSecModel@genie::EventGenerator/QEL-CC"> genie::HybridXSecAlgorithm/CRPASuSAv2Hybrid-QEL </param>

I have a full list of example configurations in another branch in my fork I can provide if it's helpful.

As a bonus, a warning message is added to the MECGenerator to warn the user if SuSA or Valencia models are ran with unexpected values of fQ3Max (getting this wrong has been responsible for a lot of wasted CPU cycles!).

[sjdolan]

Looking at the conflicts: The one related to the data file is just because I renamed the tensor directory (to indicate that it also contains the CRPA tensors), so this should be a trivial fix. The one related to SuSAv2QELPXSec.cxx is really just missing one fairly small commit from Julia (https://github.com/GENIE-MC/Generator/commit/25759365d465e8e544dbb0cfc8cdb0f523d1996f) which should be pretty easy to add back in (it also misses some updates to header info).

[mroda88]

About the conflicts, can I suggest we first merge the present master into your branch? If you want I can open the PR for you to fix this problem.

[sjdolan]

I resolved the conflicts after merging the GENIE master into my dev branch, the code should now be ready for review.

[sjdolan]

Thanks for the review @mroda88. Your comments have been addressed.