A thorough exploitation of VH production to probe New Physics in the SMEFT

by Dr Alejo Rossia

Tuesday 19 Nov 2024, 13:00 → 14:00 Europe/Brussels

E/3rd floor-E.349 - Seminar room (E.349) (Marc de Hemptinne (chemin du Cyclotron, 2, Louvain-la-Neuve))

The absence of evidence for new particles at the LHC has caused a paradigm shift in Beyond Standard Model Physics searches. The community moved on to broadly looking for small deviations from the SM predictions in highly precise measurements. The SM Effective Field Theory (SMEFT) has emerged as the preferred theoretical framework to guide and interpret such exploration. Not all processes are equally suitable to constrain the different parameters in the SMEFT. From early on, Drell-Yann and diboson production were identified as ideal processes to look for BSM in the SMEFT framework. Diboson production encompasses several processes such as WW, WZ, HH and VH production. In this talk, I will focus on the physics of VH, i.e. WH and ZH, production at LHC. A simple differential analysis of this process already offers great sensitivity to several dimension-6 WCs. However, that is far from reflecting the phenomenological richness of this process. A double binning allows for an increase in sensitivity to some of those WCs and to probe CP-odd effects. I will discuss the NLO QCD corrections to CP-odd interference and its phenomenological implications. Additionally, I will show how a departure from flavour-universality in the WCs makes it possible to use the gluon-fusion component of ZH production as a probe for top couplings. A different twist in the flavour assumptions of the WCs allowed us to rethink WH production as a probe for exotic BSM scenarios that naively would have been probed via flavour observables. Prospects for future colliders and different Higgs decay channels, impact on global fits and recent experimental efforts will also briefly discussed.