VEP associated to particles

[bkhelifi]

Dear all,

Before starting the discussion into the Semantics WG, here is the VEP UCD for new particles: https://voparis-gitlab.obspm.fr/vespa/ivoa-standards/semantics/vep-ucd/-/blob/master/VEP-UCD-26-particle_types.txt

Any objection?

[iannevans]

Dear all,

Before starting the discussion into the Semantics WG, here is the VEP UCD for new particles: https://voparis-gitlab.obspm.fr/vespa/ivoa-standards/semantics/vep-ucd/-/blob/master/VEP-UCD-26-particle_types.txt

Any objection?

This doesn't match the vocabulary changes proposed in the draft HEIG ObsCore note.

You have added phys.particle.muon, which is not included in the note (we should modify the note), but are missing phys.particle.electron (which you wanted to redefine to under the phys.particle hierarchy consistency) and also physical.particle.photon. The latter is needed in order to be able to define photon flux-related keywords under the phot.flux.particle hierarchy; these are fundamental quantities in much of high energy astrophysics (because the response matrix often makes conversion to energy fluxes less robust) and are quite distinct from counts fluxes under the phot.count hierarchy.

[loumir]

We have discussed the phys.particle hierarchy in a semantics meeting in December .
there is green light in principle to add the various particles proposed in VEP-UCD-26-particle_types.txt but we need to refine the definitions and rationale .
For phys.particle.muon , this is used in a use case for some analysis process for gamma data for instance . (cf CTA team)
For electron , the UCD vocabulary already has "phys.electron" used in many data collections , so the change of the term will break existing services.

I suppose we need to examine the photon flux-related keywords and columns of some data example , in order to check if existing UCD in the phot.* hierarchy would fit or not.
Can we have an example of the quantity recorded for flux . We would need to clarify better the case of photon particle , and the flux measurement.

best , Mireille

[YouSchnabel]

Just adding a few cents from the neutrino side: as far as I understand, these are some of the primary particles observed in gamma astronomy, however, they seem to be distinguished rather by their signature than by the particle type: for protons, it distinguishes particle and antiparticle, for muons it does not, and cosmicrays can be almost "everything" else. Extending this to the neutrino regime, would that mean we distinguish between neutrinos producing track-like events (charged-current muon-neutrino interaction) and showers (almost all the other interaction channels). Or is it particle.neutrino or particle.muonneutrino? For particles, the list of possible values is much larger than those proposed, and becomes even larger when not considering the detected particle only but the primary particle or messenger.

So it would be good to clarify or distinguish a) detector signatures b) detected particle c) primary particle. Only a) should always be assigned for all events (at least to some certainty), b) and especially c) can sometimes not be assigned from measurements.

[loumir]

Thanks Uta ,
I think we focus on what has been detected , and not on a full description of all particles in physics .
UCDs help to annotate what has been observed in the first place.