Replace `arxiv` metadata field with `inspirehep` field?

[cschwan]

I just realized that we only have an arxiv metadata field, which for some datasets is empty, because there isn't a paper on arxiv! This often the case for the older datasets, but also for a few new ones.

I therefore suggest to add the inspirehep.net reference and remove (?) the arxiv field; we should be able to get the arxiv field from the inspirehep entry. What do you think?

[felixhekhorn]

Actually the new CommonData buildmaster/NMCPD/metadata.yaml has both (which is a bit redundant); I seem to remember that some even don't have either (e.g. https://github.com/NNPDF/runcards/blob/master/nnpdf31_proc/HERA_CC_318GEV_EM_SIGMARED/metadata.txt)

[alecandido]

I therefore suggest to add the inspirehep.net reference and remove (?) the arxiv field; we should be able to get the arxiv field from the inspirehep entry. What do you think?

I would add inspirehep as you suggest, and downgrade the arxiv entry to "optional": for those that already have it, I don't believe it is particularly harmful to keep (it is not going to become incosistent).

[cschwan]

That's a good idea; let's do that.