Speaker
Description
The first results of the Fermilab Muon $g−2$ experiment are in full agreement with the previous BNL measurement and push the world average deviation in $\Delta a_\mu$ from the Standard Model to 4.2 $\sigma$. In this talk I will present an extensive survey of its impact on beyond the Standard Model physics, focusing on simple extensions of the standard model, based on arXiv:2104.03691. In this work we used state-of-the-art calculations and a sophisticated set of tools to make predictions for $a_\mu$, dark matter and LHC searches. We examined a wide range of simple models with up to three new fields which represent some of the few ways that large $\Delta a_\mu$ can be explained. The results show that the new measurement excludes a large number of models and provides crucial constraints on others. Generally, these models provide viable explanations of the $a_\mu$ result only by using rather small masses and/or large couplings with chirality flip enhancements, which can lead to conflicts with limits from LHC and dark matter experiments. I will present results for a range of models extending the standard model by one, two and three new fields including scalar leptoquarks and simple models constructed to explain dark matter and $g-2$ simultaneously.
