Tuesday, 24 May 2016

Planck 2016 Liveblog: Day Two Session Three

Back from lunch, where I made the mistake of indulging in three glasses of wine.  Time for some hardcore BSM, I guess.

3:00 pm: Non-SUSY BSM searches at ATLAS and CMS, Todd Adams

American in Spain compares our work to Columbus sailing off and finding a new world.  Start with the 750 GeV diphoton excess, exciting but the only thing we can ultimately say is that we need more data, coming soon.  Note that there is no evidence for a Zγ excess to go along with it. In a more general sense, too, the existence of this excess has ensured that many searches involving dibosons (for e.g.) have been extended down to at least that mass range.

Various mono-X searches.  Much as we have come to expect from these channels.  Dijet resonances, see above.  It's all almost magical the way the experimentalists deal with their conditions to set these strong limits, but we increasingly face the problem that we end with nothing to suggest that the SM is not all there is.

Ditop resonance searches pushing RS KK gluon up to over 3 TeV with the initial run 2 data.

Dijet searches at 750 GeV?  Not sure if there are plans.  Background is very large, which might make it pointless; would need good control of systematics.

3:20 pm: Electroweak top-quark pair hadroproduction in the presence of Z' bosons in POWHEG, Ingo Scheinbein

Z's usually most constrained by leptonic final states, but this is not guaranteed.  Special role of top quark motivates considering it as a final state.  Because we are dealing with coloured objects, must consider NLO QCD corrections, not previously computed.  Interference between signal and background is an order-1 effect.

3:40 pm: Drell-Yan production of multi-Z's at the LHC, Juri Faschi

That's multi-Z primes in the title.  Unlike the previous talk, this uses the dilepton final state.  Searches for single Z' resonances are well-understood, whether the Z' is narrow or wide.  Here, consider what is the optimal strategy if multiple vector production is the leading channel.  I think this is supposed to be motivated by some 5D string-inspired theory, but if that's the case, if would be good to say why diboson production will dominate.  Seriously, I don't see how the first handful of slides connect to the rest of this talk.

4:00 pm: Impact of LHC monojet searches on new physics scenarios, Suchita Kulkarni

Applying monojet searches to two scenarios.  First is connected to 750 GeV particle, and to momentum-dependent DM couplings.

750 GeV particle is scalar mediator with effective couplings to gauge bosons.  DM is fermionic.  Monojet searches place non-trivial constraints that, in particular, exclude 45 GeV width.

Momentum dependence, blah blah blah.

4:20 pm: Probing the interplay between TeV scale heavy vector resonances and top partners at the LHC, Bithika Jain

Composite Higgs models where the vector resonances decay to top partners rather than directly to the SM.

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