Wednesday, 11 November 2015

KIAS-CFHEP Workshop Liveblog: Day Three Session Two

We return for the final session of this short day with two talks marked as 'TBA'.

11:20 am: Mixing angles from families unified GUT,  Jihn E. Kim

Apparently was going to be an axion talk, which we start with anyway.  Well, we talk about gravity and inflation, obviuosly.  Why, exactly, did we start with a slide unrelated to the rest of the talk?  I might have been more willing if it wasn't going on about string axions, and I'm just not in the mood this morning.

CKM matrix.  And formulae that are literally too small to read.  You can talk about what they mean all you want, I have no idea what is going on there.

Runs long, of course, by ten minutes.

12:00 pm: TBA Tsumura Koji

Title gets a laugh from other people.  Real title: Landau Pole from Scalar N-plets.  Higgs couplings: possible deviation in couplings to massive vectors?  If there, possible explanation with extra scalar fields.  Constraints, especially T parameter, strongly constrain choices.  Solutions exist (zero tree-level shift) with 7-plet, 26-plet, and so on.

Also DM motivation.

Large multiplets have large couplings which bring perturbation into question. Landau pole for hypercharge happens below Planck scale, and weak coupling no longer asymptotically free.

Landau poles for new scalar quartics also problematic.  Even in conservative case where quartic vansishes at threshold, large gauge corrections lead to finite scale for pole.  Fourplets and larger are not valid up to Planck scale; for sevenplets problems at only a few hundred TeV.

This implies that (e.g.) for DM must include effects of dimension 5 and 6 operators: suppressed by relatively low scales.

Do regions exist where effects from Higgs portal couplings cancel with other loops, making things better?  Not clear either way.

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