We now return to the CosPA liveblog.
09:00 am: Theory for Neutrino Mixing, Xiao-Gang He
After reviewing neutrino mixing phenomenology and the Nobel prize it won this year, we've briefly touched on see-saw and loop models for masses. The PMNS matrix flies by, and now the PDG values for neutrino masses. In the last year we have, for the first time, started to get evidence for the non-zero value of the CP-violating phase.
I'm having difficulty seeing an overall structure in the talk. The slides are already available online, thankfully, it's helping me keep up.
So we are circling around the point that non-zero θ13 excludes tri-bimaxial mixing. Except, of course, it doesn't because people aren't willing to abandon ideas; so TBM plus small perturbation is now popular. Comparison drawn to early-90s work on generating small atmospheric/solar angles. GUT theories always popular, such as an SO(10) model that explains the 23 non-gauge parameters of the SM with 18 high-scale parameters.
T2K possible resolution to CP-phase/hierarchy questions.
Some "model building" of the standard flavour form: choose some Yukawa structure and play around with the algebra. Slides full of equations with no obvious intuitive interpretation given.
Question: A4 not a good matrix for SUSY (boo-hoo!).
09:45 am: Towards gauge theory for EW scale DM, Ko Pyungwon
Most important lesson from LHC so far is that local gauge principle works? Really?
For a talk about DM, a lot of discussion about the Higgs so far. I must have blinked and missed the claimed motivation for renormalisable theories over EFTs. Not that I don't know what that is, I just didn't see it and suddenly we're in a discussion of whether to write theories that respect SU(3)xU(1) or SU(3)xSU(2)xU(1). (Is there really anyone who advocates for the former?) Oh wait, we're talking about dilatons. For some reason.
Okay, moving on to some interesting questions. Point raised about stability in non-SUSY models, a fair question when your symmetry is imposed by hand. Raised and then dropped (maybe we'll come back to it).
Just skipped several slides without even mentioning them.
And another one.
Okay, a good question: are there any generic predictions that can be made for hidden sector DM models coupling through a portal? Or at least a Higgs portal? Well, why bother talking more about that, let's move on!
So we have apparently reached the first item on the outline presented at the start of the talk, 20 minutes in. Namely, the EFT vs renormalisable theory framework, in the specific context of Higgs portal models, specifically specifically the fermion Higgs portal. The conclusions in that limited case are the same as in the general case, namely that you have to UV complete at the LHC. Claimed that minimal UV completion (with scalar singlet) not studied; does he mean ever, or before his paper of 4 years ago? Higgs signal strengths weakened (of course, due to mixing). Direct detection signals suppressed by destructive interference, weakening direct detection constraints. New scalar can modify vacuum stability.
Seems similar conclusions arise for vector Higgs portal, though not discussed in any detail.
The GCE with a vector DM model ... that I don't think was defined.
Connection between Higgs portal DM and Higgs invisible width in context of renormalisable UV-complete models. Connection varies from usual picture, depends on mass of additional scalars.
Skipped another 5 to 10 slides without comment!
Discrete symmetries can be derived from broken gauge symmetries. Shocking. Something about extra states, that's not even slightly generic.
By my estimate, we've now skipped about 40 slides. That would be enough for a talk of this length by itself.
09:00 am: Theory for Neutrino Mixing, Xiao-Gang He
After reviewing neutrino mixing phenomenology and the Nobel prize it won this year, we've briefly touched on see-saw and loop models for masses. The PMNS matrix flies by, and now the PDG values for neutrino masses. In the last year we have, for the first time, started to get evidence for the non-zero value of the CP-violating phase.
I'm having difficulty seeing an overall structure in the talk. The slides are already available online, thankfully, it's helping me keep up.
So we are circling around the point that non-zero θ13 excludes tri-bimaxial mixing. Except, of course, it doesn't because people aren't willing to abandon ideas; so TBM plus small perturbation is now popular. Comparison drawn to early-90s work on generating small atmospheric/solar angles. GUT theories always popular, such as an SO(10) model that explains the 23 non-gauge parameters of the SM with 18 high-scale parameters.
T2K possible resolution to CP-phase/hierarchy questions.
Some "model building" of the standard flavour form: choose some Yukawa structure and play around with the algebra. Slides full of equations with no obvious intuitive interpretation given.
Question: A4 not a good matrix for SUSY (boo-hoo!).
09:45 am: Towards gauge theory for EW scale DM, Ko Pyungwon
Most important lesson from LHC so far is that local gauge principle works? Really?
For a talk about DM, a lot of discussion about the Higgs so far. I must have blinked and missed the claimed motivation for renormalisable theories over EFTs. Not that I don't know what that is, I just didn't see it and suddenly we're in a discussion of whether to write theories that respect SU(3)xU(1) or SU(3)xSU(2)xU(1). (Is there really anyone who advocates for the former?) Oh wait, we're talking about dilatons. For some reason.
Okay, moving on to some interesting questions. Point raised about stability in non-SUSY models, a fair question when your symmetry is imposed by hand. Raised and then dropped (maybe we'll come back to it).
Just skipped several slides without even mentioning them.
And another one.
Okay, a good question: are there any generic predictions that can be made for hidden sector DM models coupling through a portal? Or at least a Higgs portal? Well, why bother talking more about that, let's move on!
So we have apparently reached the first item on the outline presented at the start of the talk, 20 minutes in. Namely, the EFT vs renormalisable theory framework, in the specific context of Higgs portal models, specifically specifically the fermion Higgs portal. The conclusions in that limited case are the same as in the general case, namely that you have to UV complete at the LHC. Claimed that minimal UV completion (with scalar singlet) not studied; does he mean ever, or before his paper of 4 years ago? Higgs signal strengths weakened (of course, due to mixing). Direct detection signals suppressed by destructive interference, weakening direct detection constraints. New scalar can modify vacuum stability.
Seems similar conclusions arise for vector Higgs portal, though not discussed in any detail.
The GCE with a vector DM model ... that I don't think was defined.
Connection between Higgs portal DM and Higgs invisible width in context of renormalisable UV-complete models. Connection varies from usual picture, depends on mass of additional scalars.
Skipped another 5 to 10 slides without comment!
Discrete symmetries can be derived from broken gauge symmetries. Shocking. Something about extra states, that's not even slightly generic.
By my estimate, we've now skipped about 40 slides. That would be enough for a talk of this length by itself.
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