Neutrino energy reconstruction from one muon and one proton events

We propose a new method of selection of high purity charge current quasielastic neutrino events with a good reconstruction of interacting neutrino energy. Performance of the method was verified with several tests using GENIE, NEUT and NuWro Monte Carlo events generators with carbon and argon targets. The method can be useful in neutrino oscillation studies with a few GeV energy beams.Comment: 8 pages, 5 figure

Charged-current Quasi-elastic-like neutrino interactions at the T2K experiment

T2K is a long-baseline neutrino oscillation experiment based in Japan. The experiment has already measured the appearance of ⌫e in a ⌫μ beam, and is hoping to measure the appearance of ⌫¯e in a ⌫¯μ beam, which would open the possibility of observing CP-violation in the lepton sector. The charged current quasi-elastic (CCQE) interaction (vμ + n -> μ− + p) is of great importance to T2K as it is expected to make up over 80% of the interactions at the oscillation peak (600 MeV). In recent years it has become clear that the most common model describing CCQE interactions on nuclei, the Relativistic Fermi Gas (RFG) model, is not able to describe low energy data on nuclear targets. An alternative model, the Spectral Function (SF) model, was implemented in the NEUT interaction generator. Relevant uncertainties in this model are identified and evaluated. The charged current quasi-elastic-like cross section is then measured using the T2K near detector, ND280, as a function of muon momentum and angle. This data is then critically compared to the predictions from two implementations of the RFG model, and also to the newly implemented SF model. The total integrated cross section is found to be (4.06 ± 0.757) x 10−39 cm2 nucleon−1. This value is currently in agreement with all three predictions

Search for heavy neutral leptons decaying into muon-pion pairs in the MicroBooNE detector

We present upper limits on the production of heavy neutral leptons (HNLs) decaying to mu p pairs using data collected with the MicroBooNE liquid-argon time projection chamber (TPC) operating at Fermilab. This search is the first of its kind performed in a liquid-argon TPC. We use data collected in 2017 and 2018 corresponding to an exposure of 2.0 x 10(20) protons on target from the Fermilab Booster Neutrino Beam, which produces mainly muon neutrinos with an average energy of approximate to 800 MeV. HNLs with higher mass are expected to have a longer time of flight to the liquid-argon TPC than Standard Model neutrinos. The data are therefore recorded with a dedicated trigger configured to detect HNL decays that occur after the neutrino spill reaches the detector. We set upper limits at the 90% confidence level on the element vertical bar U-mu 4 vertical bar(2) of the extended PMNS mixing matrix in the range vertical bar U-mu 4 vertical bar(2) <(6.6-0.9) x 10(-7) for Dirac HNLs and vertical bar U-mu 4 vertical bar(2) <(4.7-0.7) x 10(-7) for Majorana HNLs, assuming HNL masses between 260 and 385 MeV and vertical bar U-e4 vertical bar(2) = vertical bar U-tau 4 vertical bar(2) = 0

Photon-rejection Power of the Light Dark Matter eXperiment in an 8 GeV Beam

The Light Dark Matter eXperiment (LDMX) is an electron-beam fixed-target experiment designed to achieve comprehensive model independent sensitivity to dark matter particles in the sub-GeV mass region. An upgrade to the LCLS-II accelerator will increase the beam energy available to LDMX from 4 to 8 GeV. Using detailed GEANT4-based simulations, we investigate the effect of the increased beam energy on the capabilities to separate signal and background, and demonstrate that the veto methodology developed for 4 GeV successfully rejects photon-induced backgrounds for at least $2\times10^{14}$ electrons on target at 8 GeV.Comment: 28 pages, 20 figures; corrected author lis