Oct 2018 - Sep 2019

The operator-observable map

by Dr Rick Gupta (IPPP Durham)


The SMEFT is a powerful way of parametrising indirect deviations in Higgs and electroweak physics. As we enter the era of higher energies and luminosities, the time has come to move from total cross-sections and rates to more differential observables. We describe here ongoing work where we propose differential observables (involving both energy and angular variables) that can uniquely identify all the different higher dimensional vertices in $Zh$ production. We also provide a similar example in $W \gamma$ production where the use of Matrix Element method is crucial to constrain certain anomalous triple gauge couplings. While vertices that lead to the dominant energy growth in the amplitude can be probed most sensitively by the LHC, angular variables become important to isolate vertices that give a sub-dominant high energy contribution. We also discuss how the bounds that can be obtained at the LHC can be compared to existing LEP bounds in this framework.