In search of the Higgs trilinear coupling: double and single Higgs processes

Tuesday, 30 October 2018 at 11:15, in Y16 G05 - Campus Irchel

One of the fundamental goals of the LHC is the study of the Higgs properties. While the couplings between the Higgs and other SM particles are known with ever increasing precisions, the Higgs self-couplings have not been directly measured. In this talk I will explore two approaches to the measurement of the Higgs trilinear self-coupling. The first half of the talk will be dedicated to the standard method based on the production of a pair of Higgs bosons. In particular I will focus on a new technique that allows the analytical calculation of the NLO corrections to the $gg\to HH$ process. In the second half, instead, I will describe a different  approach based on the measurement of single Higgs processes. The method relies on the effects that electroweak loops featuring an anomalous trilinear coupling would imprint on single Higgs production at the LHC. We find that the bounds on the self coupling obtained in this way are competitive with those from Higgs pair production and will be further improved in the current and next LHC runs.