Constraint of the MINERν A medium energy neutrino flux using neutrino-electron elastic scattering

Abstract

Elastic neutrino scattering on electrons is a precisely-known purely leptonic process that provides a standard candle for measuring neutrino flux in conventional neutrino beams. Using a total sample of 810 neutino-electron scatters after background subtraction, the measurement reduces the normalization uncertainty on the νµ NuMI flux between 2 and 20 GeV from 7.5% to 3.9%. This is the most precise measurement of neutrino-electron scattering to date, will reduce uncertainties on MINERνA's absolute cross section measurements, and demonstrates a technique that can be used in future neutrino beams such as LBNF.PACS numbers: definitely not 99.99+z

Testing New Physics Explanations of the MiniBooNE Anomaly at Neutrino Scattering Experiments

“…neutrino interactions, as they predict large number of events at higher energies [42][43][44][45][46][47][48][49]. Thus, our analysis uses high-energy neutrino-electron scattering measurements [55][56][57][58][59][60][61][62][63][64]. This process is currently used to normalize the neutrino fluxes, due to its well-understood cross section, and has been a fertile ground for light NP searches [65][66][67].…”

“…Our technique is complementary to recent searches for coherent singlephoton topologies [68]. Since the upscattering process has a threshold of tens to hundreds of MeV, we focus on two high-energy neutrino experiments: MINERνA [58][59][60][61], a scintillator detector in the Neutrinos at the Main Injector (NuMI) beamline at Fermilab, and CHARM-II [62][63][64], a segmented calorimeter detector at CERN along the Super Proton Synchrotron (SPS) beamline. These experiments are complementary in the range of neutrino energies they cover and have different background composition.…”

“…It contains all events with shower energies between 3 and 24 GeV, and our final cut on Eθ 2 is fixed at 28 MeV. For MINERνA , the event selection is identical for the low-energy (LE) and medium-energy (ME) analyses [59,60]. The minimum shower energy required is 0.8 GeV in order to remove the π 0 background and have reliable angular and energy reconstruction.…”

“…The recent MINERνA ME data contains an excess in the region of large dE/dx [59], where the NP events would lie. However, this excess is attributed to NC π 0 events, and grows with the shower energy undershooting the rate require to explain the MiniBooNE anomaly.…”

“…In our nominal MINERνA LE (ME) analysis, we allow for 10% uncertainty on the flux [76], and 30% (40%) uncertainty on the background motivated by the amount of tuning performed on the original backgrounds. Note that the nominal background predictions in the MINERνA LE (ME) analysis overpredicts (underpredicts) the data before tuning, and that tuning parameters are measured at the 3% (5%) level [58,59]. We also perform a background-ignorant analysis in which we assume 100% uncertainty for the background normaliza-tion, which changes our conclusions by only less than a factor of two.…”