Abstract
In this contribution we discuss next-to-next-to-leading order hadronic and four-loop QED contributions to the anomalous magnetic moment of the muon.
Highlights
The anomalous magnetic moment of the muon, aμ, is among the most precise measured quantities in particle physics
It is interesting to note that the three-loop term is only less than a factor four larger than the four-loop counterpart. It is worth comparing the numbers in Eq (5) to the universal contributions contained in A1 which read [13]
For more than a decade the measured and predicted results for the anomalous magnetic moment of the muon show a discrepancy of three to four standard deviations. This circumstance has triggered many publications which try to interpret the deviation with the help of beyond-SM theories
Summary
The anomalous magnetic moment of the muon, aμ, is among the most precise measured quantities in particle physics. Since many years one observes a discrepancy of about three to four standard deviations which survives persistent all improvements. This concerns both the experimental data and theoretical calculations entering the prediction. The numerically most important QED contributions at four-loop level arise from light-by-light-type diagrams (i.e. the external photon does not couple to the external muon line) containing a closed electron loop. This well-defined subset has been considered in Ref.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
