First Measurement of Differential Charged Current Quasielasticlike ${\nu }_{\mu }$-Argon Scattering Cross Sections with the MicroBooNE Detector

We report on the first measurement of flux-integrated single differential cross sections for charged-current (CC) muon neutrino (${\nu }_{\mu }$) scattering on argon with a muon and a proton in the final state, ${}^{40}\mathrm{Ar}$ $({\nu }_{\mu },\mu p)X$. The measurement was carried out using the Booster Neutrino Beam at Fermi National Accelerator Laboratory and the MicroBooNE liquid argon time projection chamber detector with an exposure of $4.59\times {10}^{19}$ protons on target. Events are selected to enhance the contribution of CC quasielastic (CCQE) interactions. The data are reported in terms of a total cross section as well as single differential cross sections in final state muon and proton kinematics. We measure the integrated per-nucleus CCQE-like cross section (i.e., for interactions leading to a muon, one proton, and no pions above detection threshold) of $(4.93\pm 0.76_{\mathrm{stat}}\pm 1.29_{\mathrm{sys}})\times {10}^{-38}{\mathrm{cm}}^2$, in good agreement with theoretical calculations. The single differential cross sections are also in overall good agreement with theoretical predictions, except at very forward muon scattering angles that correspond to low-momentum-transfer events.

Figure 1

The flux-integrated single differential $\mathrm{CC}1\mathrm{p}0\pi$ cross sections as a function of the cosine of the measured muon scattering angle. Inner and outer error bars show the statistical and total (statistical and systematic) uncertainty at the $1\sigma$, or 68%, confidence level. Colored lines show the results of theoretical absolute cross section calculations using different event generators (without passing through a detector simulation). The blue band shows the extracted cross section obtained from analyzing MC events propagated through our full detector simulation. The width of the band denotes the simulation statistical uncertainty.

Figure 2

As Fig. 1, but for the differential cross sections as a function of measured muon momentum (left) and measured proton scattering angle (middle) and momentum (right). Cross sections are shown for the full measured phase space (top) and for events with $\cos ({\theta }_{\mu })<0.8$ (bottom).

Figure 3

The flux-integrated single differential $\mathrm{CC}1\mathrm{p}0\pi$ cross sections as a function of $Q_{\mathrm{CCQE}}^2=(E_{\nu }^{\mathrm{cal}}-E_{\mu }{)}^2-({\overrightarrow{p}}_{\nu }-{\overrightarrow{p}}_{\mu }{)}^2$ and $E_{\nu }^{\mathrm{cal}}=E_{\mu }+T_p+BE$, where $BE=40\mathrm{MeV}$ and ${\overrightarrow{p}}_{\nu }=(0,0,E_{\nu }^{\mathrm{cal}})$. Inner and outer error bars show the statistical and total (statistical and systematic) uncertainty at the $1\sigma$, or 68%, confidence level. Colored lines show the results of theoretical absolute cross section calculations using different event generators (without passing through a detector simulation). The blue band shows the extracted cross section obtained from analyzing MC events passed through our full detector simulation.