School of Physics and Astronomy

Interpreting ATLAS Higgs data with the example of the decay of the Higgs to tau pairs

22 November 2018

Time: 3:00 - 4:30pm
Speaker: Michel Janus
Venue: G.O. Jones, room 410

The discovery of the Higgs Boson by the ATLAS and CMS collaborations in 2012 has been considered to provide one of the last missing pieces of the Standard Model of Particle Physics (SM). But it also opens an avenue into new searches for phenomena beyond the Standard model in the Higgs sector. This talk details parts of the story of how the Higgs was found, focussing on the example of the decay channel H->tautau and also presents the most recent measurements in this channel with the ATLAS detector. One of the most promising tools for studying the newly discovered boson and for pin-pointing deviations from SM predictions is the effective-field-theory (EFT) approach. In this approach one parametrizes the interaction of the Higgs boson in an effective Lagrangian that contains the most general tensor structure possible. This includes the couplings predicted for the Higgs Boson of the Standard Model as well as beyond-SM couplings parametrized using dimension-six operators. The strength of the interactions described by these operators can then be fitted to LHC data. In this talk an introduction into the EFT framework is given together with some example applications for studying the Higgs coupling to vector bosons. Slides: https://indico.ph.qmul.ac.uk/indico/conferenceDisplay.py?confId=382