Probing B anomalies via dimuon tails at a future collider

We investigate the sensitivity of future proton-proton colliders to a contact interaction of the form 1/Lambda(2)((b) over bar (L)gamma(mu)s(L))((mu) over bar (L)gamma(mu)mu(L)) as indicated by the longstanding rare B-decay anomalies. We include next to leading order (NLO) QCD and electroweak effects and employ an optimized binning scheme, and carefully validate our background calculation against ATLAS and CMS data. We find that the FCC-hh with 40 ab(-1) of luminosity is able to exclude scales A up to 26 TeV at 95% CL, and discover Lambda up to 20 TeV. While this is not quite enough to exclude or discover the current best-fit value of 39 TeV, this can in principle be achieved with more luminosity and/or higher energy, as we study quantitatively. Our analysis is conservative in that it assumes only a (b) over bars mu mu contact interaction.