  Neutrino charged-current quasielastic-like scattering, a reaction category
extensively used in neutrino oscillation measurements, probes nuclear effects
that govern neutrino-nucleus interactions. This Letter reports the first
measurement of the triple-differential cross section for $\nu_{\mu}$
quasielastic-like reactions using the hydrocarbon medium of the MINERvA
detector exposed to a wide-band beam spanning 2 $\leq$ E$_\nu \leq$ 20 GeV. The
measurement maps the correlations among transverse and longitudinal muon
momenta and summed proton kinetic energies, and compares them to predictions
from a state-of-art simulation. Discrepancies are observed that likely reflect
shortfalls with modeling of pion and nucleon intranuclear scattering and/or
spectator nucleon ejection from struck nuclei. The separate determination of
leptonic and hadronic variables can inform experimental approaches to
neutrino-energy estimation.
