The aim of this group is to define a list of exotic production mechanisms of the 125 GeV Higgs, and understand how they can be disentangled from standard production. We also aim at clarifying the interplay of the EFT approach and the exotic production channels.

===== Interested people: =====
Giacomo Cacciapaglia, Thomas Flacke, Devdatta Majumder, Aldo Deandrea, Andrey Katz, Jose Miguel No, Alberto Parolini, Felix Yu, Aurelio Juste, Benjamin Fuks, Alexandra Oliviera


Slides (pdf) for Les Houches summary meeting
[[https://www.dropbox.com/s/1vvlxkde87id0sh/Exotic_prod.pdf?dl=0]]


===== Topics we discussed during the first meeting ====

 - contamination of the SM single-Higgs searches by Exotic production ([[http://arxiv.org/abs/1404.2924|1404.2924]])

 - classification of Exotic production mechanisms (proposal by Felix Yu):
     * Resonant

     * Non Resonant (cascade decays):
       * asymmetric
       * symmetric

 - list of exotic productions (pair and single):
    * VLQ pair production: QQ -> h j h j   ([[http://arxiv.org/abs/1312.5316|1312.5316]])
      * Setting up a toy analysis:
      * (Alexandra) in the 4b final state we could try an "scale invariant" analysis to this channel to discover where it starts to look like with X>HH>4b because the T' boost (inspired by http://arxiv.org/abs/1303.6636)


    * VL lepton pp: LL -> h l h l, h l h nu, h nu h nu
    * ...

 - Resonance h X: what still needs to be done?
     * h l
     * h gamma
     * h V broad resonance

- Double-higgs production from di-quarks de-excitations into the lighter states. Possible issues
      * direct constraints (quite strong for triplets, mild for sextets)
      * competition between Q*->Qh and Q*->QZ (depends on the mixing angle)
      * indirect constraints from ggH coupling (can be really strong for sextets)  
      * non-colored di-quarks (couplings to Qd and Qu)?
      * full list of scalar colored di-quarks [[http://arxiv.org/pdf/1105.3161.pdf]]

- Double-Higgs production via loops of heavy states


===== Benchmark models =====


==== VLQ pair (and single) production  ====

A single up-type VLQ that couples uniquely to the Higgs and an up or charm (up-type are theoretically preferred [[http://arxiv.org/abs/1102.1987| 1102.1987]]).

Interesting channels for double-Higgs production:

- Pair production: QQ -> hj hj

- single production: q g -> Q h -> hj h

- t-channel exchange: q q -> h h

- loop contribution (box diagram): g g -> h h

Pair production cross section at 8 TeV (from [[http://arxiv.org/abs/1111.5869|1111.5869]]):

{{:2015:groups:higgs:xsecvlq8.png?350|}}

Some references: [[http://arxiv.org/abs/1302.0270|1302.0270]], [[http://arxiv.org/abs/1312.5316|1312.5316]].

==== coloured scalar pair production  ====

The model consists on two coloured scalars, that couple to each other via a Higgs. The lightest one decays in di-jets (or jet-lepton).

- pair production of phi2 -> [h phi1] or [jj/jl]: final states: hjj jj, hjj hjj  /  hjl jl, hjl hjl

- constraints from ggf

- bounds from pair di-jet resonances or leptoquark searches

{{:2015:groups:higgs:xsecsscalar.png?350|}}
{{:2015:groups:higgs:xsecsscalar.pdf|}}

NLO production cross section for a scalar colour triplet (solid) and a "slepton" (dashed) at 8TeV (red) and 13TeV (blue), (coloured from [[http://arxiv.org/abs/1412.5589|1412.5589]], slepton from [[http://arxiv.org/abs/1310.2621|1310.2621]]).

** Bounds from hh -> bbgg, and di-jet pair resonances, on a scalar triplet decaying into hjj and jj **

{{:2015:groups:higgs:xsec8.png?350 |}}

{{:2015:groups:higgs:exclusion3.png?250|}}


LEFT: NLO production cross section at 8 TeV for a scalar triplet (from [[http://arxiv.org/abs/1412.5589|1412.5589]]).

RIGHT: exclusion from (RED) ALTAS hh->bbgg ([[http://arxiv.org/abs/1406.5053|1406.5053]]), and (BLUE) CMS di-jet pair resonant search ([[http://arxiv.org/abs/1412.7706|1412.7706]]), as a function of the mass of the scalar triplet and the BR(hjj). BR(jj) = 1-BR(hjj).


** Bounds from hh->multilepton searches **

[[http://arxiv.org/pdf/1410.2751.pdf]]


==== VLL (vector-like leptons) ====



===== Previous meetings =====


discussion of 16/6/15

{{:2015:groups:higgs:2015-06-16_17.24.08.jpg?200|}}

{{:2015:groups:higgs:2015-06-16_18.03.37.jpg?200|}}

discussion of 18/6/15

{{:2015:groups:higgs:2015-06-18_17.56.28.jpg?200|}}