====== Exotics decay of heavy bosons in VLQs and extra scalars ======
__People interested:__ Daniele Barducci, Thomas Flacke, Minho Son, Benjamin Fuks, Devdatta Majumder, Ramona Groeber, Haiying Cai, Tetiana Berger-Hryn'ova , Alexandra Carvalho, Abhishek Iyer Tom Rizzo...

**Motivations and goal**

  * Exotic decays such as $\rho \to T \bar t$ can eat branching ratio from standard search channels (dilepton, dibosons), rendering these direct searches less sensitive (see e.g. [[https://arxiv.org/pdf/1511.01101.pdf]] Fig. 3)
  * Investigate the signatures arising from the decay of a heavy bosons (spin 0 and spin 1) in SM quarks and VLQs, e.g. Z'-> VLQ top, or extra light scalars, e.g. Z' -> Z a


Possibile bosons involve

  * spin 1 color singlet
  * spin 1 color octet
  * spin 0 color singlet
  * ...

**Strategies**

  * Categorize the possible decays of the identified resonances. This was done for VLQ in Les Houches 2015

{{:2017:groups:np:screen_shot_2017-09-07_at_10.23.38_am.png?400|}}
{{:2017:groups:np:screen_shot_2017-09-07_at_10.23.45_am.png?400|}}

  * Check the sensitivity of SM searches. For example the $\rho \to T \bar t \to Z t \bar t$ has the same final state of the SM $t\bar t Z$ search
  * Check the sensitivity of single production mode. Also in this case the final state can be the same. However single production searches usually exploit a forward jet, which is not present here


**References**
  * "Search for a heavy resonance decaying to a top quark and a vector-like top quark at 13 TeV" https://arxiv.org/pdf/1703.06352.pdf
  * ttZ resonance search https://arxiv.org/pdf/1610.08810.pdf
  * Massive vectors couplings https://arxiv.org/pdf/1607.07621.pdf
  * Minimal matter https://arxiv.org/pdf/0908.1567.pdf
  * Simplified model with Spin 0 - Tt, (T-> Wb,Zh,th) where T is singlet top partner.   
     * https://journals.aps.org/prd/abstract/10.1103/PhysRevD.95.035039. with possibility of RS KK gluon
     * https://arxiv.org/pdf/1609.06502.pdf
     * https://arxiv.org/pdf/1411.1771.pdf

**Blackboard**

  * 20-06-2017
{{: 2017:groups:np:20170620_151120.jpg | 20-06-2017}}




**Further questions**

  * From the polarization of the top arising from the decay is it possible to infer the representation to which the heavy boson belongs, i.e. predict the presence of other states?