Monday, 25 May 2015

Planck 2015 Liveblog: Day One, Session Two

Refreshed by two coffees, and learning that lunch has been paid for, we start the second session of the conference.  This set of talks is very SUSY-focused.

11:00 am: "Supersymmetric Dark Matter after Run 1 at the LHC: from a TeV to a PeV", Keith Olive

More SUSY, with a DM focus including to highish scales.  The SUSY motivations are unchanged despite it's non-discovery.  Discusion of various constrained models (CMSSM, MSUGRA, NUHM, PGM) with 4/3/5/2 parameters.  Apparently they still all work.

Higgs mass at upper limit for SUSY prediction, which means few models give it.  This is "why" we didn't find SUSY yet.

In 2009, 1-sigma theoretical bounds in the low mass region.  As I noted with John Ellis's talk, SUSY just above the limits, like it always is.  Expected to see SUSY at LHC or direct detection by now, based on those predictions.

A discussion of the coannihilation strips with stop and stau, and the note that these do not go up to arbitrarily high mass (in the CMSSM).  This lets us, in principle, rule out these model.

NUHM1 models can offer large regions of valid relic density with LSP becomes Higgsino-like (set only by μ.

Stuff on "Pure Gravity Mediation".  Does he mean anomaly mediation?  Gluino coannihilation; what model was that in?  I would be able to follow things much more easily if I could access the talks on my laptop.

What if relic density measurement changes? Not much.  RD measurement not going to change much.  Also, position of region will not shift much as needs special conditions.
Fine Tuning?  Essentially, admits model is fine tuned (like everything).

11:30 am: "A No-Scale Model to fit them all", Dimitri Nanopoulos

And in the darkness bind them.

Like Keith Olive, Dimitri is talking about work in collaboration with John Ellis.  This is making today the John Ellis show.

My laptop is running out of power.  So I'm going to pass over this talk in favour of the last one, which I am more interested in.

Two talks, started on time, now over ten minutes late.  That is ridiculous.

12:00 pm: "GMSB with light stops", Mariano Quiros

An aim for naturalness with gauge mediation.  Looks like a number of people have decided to skip this talk, I can hear them outside again.

Generally, GMSB struggles to reproduce the Higgs mass because the A-terms come in at two loop.  This means you need stops at 5 TeV or heavier in minimal GMSB.  Options to extend mediation, without extending the gauge group, by either adding direct superpotential couplings or extra scalars coupling to the Higgs (singlets or triplets).  Adding triplets has the problem of generating a large Δρ when the triplet gains a VEV.  So the goal is to add a custodial symmetry to try and avoid this problem.

Unfortunately, despite turning my laptop off for the last talk, it's clear it's not going to last much longer, and the internet is so bad it takes several attempts to update.  So I'm going to have to end here also.

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