| Summary: | We report a search for an anomalous excess of inclusive charged-current (CC) νe interactions using the Wire-Cell event reconstruction package in the MicroBooNE experiment, which is motivated
by the previous observation of a low-energy excess (LEE) of electromagnetic events from the MiniBooNE experiment. With a single liquid argon time projection chamber detector, the measurements
of νµ CC interactions as well as π
0
interactions are used to constrain signal and background predictions of νe CC interactions. A data set collected from February 2016 to July 2018 corresponding to
an exposure of 6.369 × 1020 protons on target from the Booster Neutrino Beam at FNAL is analyzed.
With x representing an overall normalization factor and referred to as the LEE strength parameter,
we select 56 fully contained νe CC candidates while expecting 69.6 ± 8.0 (stat.) ± 5.0 (sys.) and
103.8 ± 9.0 (stat.) ± 7.4 (sys.) candidates after constraints for the absence (eLEEx=0) of the median signal strength derived from the MiniBooNE observation and the presence (eLEEx=1) of that
signal strength, respectively. Under a nested hypothesis test using both rate and shape information
in all available channels, the best-fit x is determined to be 0 (eLEEx=0) with a 95.5% confidence
level upper limit of x at 0.502. Under a simple-vs-simple hypotheses test, the eLEEx=1 hypothesis
is rejected at 3.75σ, while the eLEEx=0 hypothesis is shown to be consistent with the observation
at 0.45σ. In the context of the eLEE model, the estimated 68.3% confidence interval of the νe CC
hypothesis to explain the LEE observed in the MiniBooNE experiment is disfavored at a significance
level of more than 2.6σ (3.0σ) considering MiniBooNE’s full (statistical) uncertainties.
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