WG2: CP violation in ttH interactions

Wednesday 27 Sept 2023, 15:00 → 17:30 Europe/Zurich

CERN

Google Doc

Activity 1

 

Including interference in the multivariate analysis, which only includes pure CP-odd vs. CP-even so far.

• Similar methodology to https://arxiv.org/abs/2309.03146 but for ttH?
• More realistic? Inclusion of backgrounds?
• Parametrised classifier, use reweighting?

We need some participation from experimentalists! Follow up with Haichen for possible experimental involvement

 

TODO:

 

Sample generation:

• Large sample of ttH events with modified yukawas
• Use reweighting to parametrise coupling dependence?

Activity 2

More global analyses including, e.g., gg -> H(+nj), to analyse complementarity and overlaps between CPV and CPC effects

See CMS study: 

https://cms-results.web.cern.ch/cms-results/public-results/publications/HIG-19-009/CMS-HIG-19-009_Figure_017.png

https://inspirehep.net/literature/1860903

https://inspirehep.net/literature/2688930

 

• Mini CPV fit: combining e.g. ggH and ttH with ( k_t, \tilde{k}_t, c_g & \tilde{c}_g )
• First approximation, VBF is SM-like
• Medium term: include the dipole
• Dipole: g t tbar & g t tbar h (old pheno study for dipole https://arxiv.org/pdf/1412.6654.pdf). Are there exp studies on this?
• Higgs CP at ATLAS+CMS https://indico.cern.ch/event/1184945/contributions/5408275/
• Also some studies using 4tops seem to exist, need to look for them
• Maybe just use STXS + some CP-sensitive binnings for ggF
• What to use for ttH?
• What about tH

TODO:

Read exp literature to see what it has actually been done and what's still uncovered or can be improved

15:00 → 15:20 CPV in ttH, introduction

Speakers: Dorival Gonçalves (Oklahoma State University), Henning Bahl