https://doi.org/10.1140/epjc/s10052-020-08611-6
Regular Article - Theoretical Physics
Effects of longitudinal short-distance constraints on the hadronic light-by-light contribution to the muon 
Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090, Vienna, Austria
b
massimiliano.procura@univie.ac.at
Received:
10
June
2020
Accepted:
29
October
2020
Published online:
2
December
2020
We present a model-independent method to estimate the effects of short-distance constraints (SDCs) on the hadronic light-by-light contribution to the muon anomalous magnetic moment 
. The relevant loop integral is evaluated using multi-parameter families of interpolation functions, which satisfy by construction all constraints derived from general principles and smoothly connect the low-energy region with those where either two or all three independent photon virtualities become large. In agreement with other recent model-based analyses, we find that the SDCs and thus the infinite towers of heavy intermediate states that are responsible for saturating them have a rather small effect on . Taking as input the known ground-state pseudoscalar pole contributions, we obtain that the longitudinal SDCs increase by 
, where the isovector channel is responsible for 
. More precise estimates can be obtained with our method as soon as further accurate, model-independent information about important low-energy contributions from hadronic states with masses up to 1–2 GeV become available.
© The Author(s) 2020
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