Alpha-alpha scattering in the Multiverse

A bstract We investigate the phase shifts of low-energy ? - scattering under variations fundamental parameters Standard Model, namely light quark mass, electromagnetic fine-structure constant as well QCD ? -angle. As a first step, we recalculate in our Universe utilizing various improvements adiabatic projection method, which leads to an improved, parameter-free prediction S- and D-wave for laboratory energies below 10 MeV. find that positive pion mass have small effect on S-wave shift, whereas lowering adds some repulsion two-alpha system. The shift turns out be more pronounced signaled by resonance parameters. Variations almost no shifts. further show up-to-and-including next-to-leading order chiral expansion, these with respect -angle can expressed terms -dependent mass.