Measurement of differential cross sections for <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>ν</mml:mi><mml:mi>μ</mml:mi></mml:msub></mml:math>-Ar charged-current interactions with protons and no pions in the final state with the MicroBooNE detector

We present an analysis of MicroBooNE data with a signature of one muon, no pions, and at least one proton above a momentum threshold of $300\text{ }\text{ }\mathrm{MeV}/\mathrm{c}$ ($\mathrm{CC}0\ensuremath{\pi}Np$). This is the first differential cross-section measurement of this topology in neutrino-argon interactions. We achieve a significantly lower proton momentum threshold than previous carbon and scintillator-based experiments. Using data collected from a total of approximately $1.6\ifmmode\times\else\texttimes\fi{}{10}^{20}$ protons on target, we measure the muon neutrino cross section for the $\mathrm{CC}0\ensuremath{\pi}Np$ interaction channel in argon at MicroBooNE in the Booster Neutrino Beam which has a mean energy of around 800 MeV. We present the results from a data sample with estimated efficiency of 29% and purity of 76% as differential cross sections in five reconstructed variables: the muon momentum and polar angle, the leading proton momentum and polar angle, and the muon-proton opening angle. We include smearing matrices that can be used to ``forward fold'' theoretical predictions for comparison with these data. We compare the measured differential cross sections to a number of recent theory predictions demonstrating largely good agreement with this first-ever dataset on argon.