00:03:41 Tracy Robyn Slatyer: https://docs.google.com/document/d/1JTEdQYD4FewS9WI_qkNmvnsSMwkXz2AcatG28JyhlDc/edit?usp=sharing 00:07:31 Tracy Robyn Slatyer: https://indico.fnal.gov/event/44939/ 00:19:24 James Buckley: Rick et al. The lower energy in the range for HAWC and LHAASO are not really thresholds - the lowest reconstructed energy for HAWC ior LHAASO is TeVish. In general, IACTs are considered to have much lower threshold - defined to be the energy at which the effective area curve peaks or reaches 1/2 max. 00:19:50 Richard Gaitskell: Thanks 00:20:07 Alex Drlica-Wagner (he/him): Slide 10: How about PBH evaporation? Could go higher! 00:22:34 Kristi Lynne Engel: The ones predicted to be evaporating today aren’t in the mass ranges as candidates for WIMPs though? So theoretically, yes, but not ones that are being observed in the final seconds of their lives by, e.g., HAWC, in the TeV 00:23:35 Kristi Lynne Engel: (Well… final stages of evaporation today) 00:23:42 Tracy Robyn Slatyer: My understanding is the PBHs that could make up 100% of the DM have Hawking radiation that peaks in the ~MeV energy range or lower, so indeed I would think that’s not a target for these high-energy observatories 00:24:19 Alex Drlica-Wagner (he/him): Ah, interesting, do you have a reference for that Tracy? 00:25:11 Alex Drlica-Wagner (he/him): That is fine, I need to run to another session in 5 minutes, but happy to continue on Slack 00:26:03 James Buckley: I think the energy range for PBHs depends sensitivity on assumptions about energy scales of new particle degrees of freedom. 00:26:34 Jodi Cooley: Slides look fine on my screen Tracy! 00:27:05 Tracy Robyn Slatyer: Ah OK Jodi, may just be an issue on my end 00:27:35 Tracy Robyn Slatyer: Alex: this definitely isn’t the most comprehensive reference but here’s a recent paper by Ranjan Laha, Julian Munoz and me about PBHs-as-DM search with INTEGRAL: https://arxiv.org/abs/2004.00627 00:27:44 Kimberly Palladino: I think if Carsten’s on slide 2 we are still seeing the title slide 00:27:47 Tongyan Lin: I’m also not seeing slide transitions 00:27:53 Marcos Santander: I also see the other slide thumbnails (not full screen), but they are readable. 00:28:03 Kristi Lynne Engel: Alex, https://arxiv.org/pdf/1911.04356.pdf covers PBH evaporation at TeV energies (and appropriately is a paper Andrea was on :) ), and I also highly recommend following up with the Fermi study for similar PBHs, but there are several links to PBHs as DM and what fraction they might make up within that paper. 00:28:43 Alex Drlica-Wagner (he/him): Yeah, the Fermi studies were what I was thinking of, but it’s been while since I’ve been connected to that 00:29:11 Andrea Albert: yeah sorry I didn't have time to go over PBHs. Survey instruments are especially good for this search since they cover a wide field of view to look for the gamma ray "burst" from PBH evaporation 00:29:18 Kristi Lynne Engel: They did a proper motion search, but also for PBH mass ranges similar to the HAWC study 00:29:58 Alex Drlica-Wagner (he/him): I’d be interested in continuing this on Slack if others are interested (sorry, I have to go run another meeting now) 00:30:38 Tracy Robyn Slatyer: indeed, sounds like a good topic for a Slack discussion 00:31:09 Alex Drlica-Wagner (he/him): I’m interested because once we get into PBH domain we bridge with CF03 00:31:26 Tracy Robyn Slatyer: yep - and maybe CF7 too 00:31:37 Tracy Robyn Slatyer: PBHs are interesting whether or not they’re DM 00:32:34 Dan McKinsey: For complementarity of accelerators vs direct detection vs indirect detection, it is useful to think in a cross-section vs mass plane, see https://arxiv.org/pdf/1305.1605.pdf which came out of the last Snowmass process 00:36:09 Tracy Robyn Slatyer: Agreed - that comparison is model-dependent, but I think it’s a good starting point at least, and in specific classes of models (like the MSSM scenarios in that paper) it can be made very concrete 00:39:00 Jodi Cooley: The problem is that it is model dependent. So, we need to be careful in explaining it so that it doesn’t appear that one technique can do it all. 00:39:46 Jodi Cooley: Unfortunately I have never seen a good way to show the complementarity and need without having some model dependance. 00:42:09 James Buckley: I think the fact that neutrino telescopes can provide the most sensitive (halo-model-independent) limits on the spin-dependent cross section is an important point to include in a final CF1 report. 00:51:04 Tracy Robyn Slatyer: That relies on the DM annihilating, right? (or am I thinking about the wrong constraints?) I agree it’s an important set of limits to discuss. 00:55:19 Pat Harding: Gamma-ray experiments can do that as well, if there are mediators in a (fairly-narrow) mass range, too. https://arxiv.org/abs/1808.05624 00:56:27 Tracy Robyn Slatyer: Thanks Pat, Jim. For heavy thermal relic WIMPs it’s a good assumption that DM particles captured in the Sun will annihilate, but for models whose abundance is set by a different mechanism (e.g. asymmetric dark matter) I think these bounds on the scattering cross section don’t necessarily apply. (But this is not my area of particular expertise, so people should feel free to correct me.) 01:03:35 Pat Harding: I believe you are correct, Tracy 01:12:26 James Buckley: Tracy - can I show one slide that addresses this question? 01:12:27 Marcos Santander: For CTA, the DM program is part of the key science projects for the observatory https://arxiv.org/abs/1709.07997 01:12:37 Tracy Robyn Slatyer: Yes Jim, please go ahead and share your slide 01:16:02 tsuguo aramaki: As a note, we started a new project called, GRAMS (Gamma-ray and Antimatter Survey), which will be the first experiment to target both MeV gamma-ray observations and antimatter-based (antideuterons and antiheliums) indirect DM searches with LArTPC. (Also indirect DM searches with MeV gamma-rays) https://arxiv.org/abs/1901.03430 01:16:48 Tracy Robyn Slatyer: Indeed, Tsuguo, we’re hoping to discuss GRAMS (and GAPS and AMEGO) in a future session - you’ll be getting an email from me :-) 01:17:09 Kimberly Palladino: Unfortunately I have to head to another meeting, but my other question somewhat follows from points of Tim’s : What data is needed from other observatories to help distinguish SM astrophysical sources from DM? 01:18:35 Tongyan Lin: I’d like to second Kim’s comment and add a subquestion for gamma rays. What is being assumed for our understanding of astrophysical gamma rays when we see DM projections of CTA, SWGO? 01:20:49 Pat Harding: Above a few TeV, there are minimal Galactic diffuse backgrounds to Galactic Center searches, unlike the larger values of e.g. Fermi-LAT. So these limits are largely independent of the assumptions of background gamma rays 01:23:35 Torsten Bringmann: Indeed, these uncertainties for CTA are also studied in detail in the recent consortium publication (2007.16129). Typically, the uncertainty from the DM profile is larger... 01:24:14 Marcos Santander: For, say the Galactic Center, they do depend on models of the density distribution of DM in the galaxy, and their annihilation spectra. 01:24:25 Tim Linden: One thing that we might want to consider — what do we think the future of DM density models is near the GC? 01:24:43 Marcos Santander: I see Torsten already pointed the CTA paper out that discusses several caveats. 01:31:13 Richard Gaitskell: Apologies - Have to leave now 01:31:21 Tracy Robyn Slatyer: Thanks for joining, Rick 01:31:39 Torsten Bringmann: The halo uncertainty also isn't that big for CTA anymore, after taking inty account systematics, because of the large observed region in survey mode. See Fig. 23 in the Appendix of the CTA paper 01:33:34 Torsten Bringmann: But this is for a small region around the GC, as also Tracy pointed out 01:34:58 Tim Linden: This is the paper on dwarf constraints that I think tracy just mentioned: https://arxiv.org/abs/2002.11956 01:35:34 Torsten Bringmann: (sorry, wrong figure ref -- it's Fig.22! ;) Even for cores, the degrading of the limits isn't so bad as one usually sees, for smaller ROIs) 01:39:24 Marcos Santander: Thank you, bye!