The Impact of Dimension-8 SMEFT Contributions: A Case Study

Understand

The use of the SMEFT Lagrangian to quantify possible Beyond the Standard Model (BSM) effects is standard in LHC and future collider studies.

• One of the usual assumptions is to truncate the expansion with the dimension-$6$ operators.
• The numerical impact of the next terms in the series, the dimension-$8$ operators, is unknown in general.
• We consider a specific BSM model containing a charge-${2 3}$ heavy vector-like quark and compute the operators generated at dimension-$8$.