Benjamin Messerly

Research

The next generation of long-baseline neutrino oscillation experiments (DUNE, Hyper-K) aims to conclusively answer the outstanding questions in neutrino oscillation physics, including the nature of lepton CP-symmetry violation and the validity of the three-neutrino paradigm. The success of this program relies on excellent beam flux simulation and precisely-known cross sections for all neutrino-nucleus scattering processes. Currently, uncertainties on these models are large, and experiments such as MINERvA, located in the NuMI neutrino beamline at Fermilab, are dedicated to reducing them. This thesis makes improvements both to flux simulation models — via reduction in hadron focusing uncertainties in the G4NuMI simulation — and to cross section knowledge via a pion production cross section measurement in the critical “transition region” between quasi-elastic and deep inelastic scattering. The cross section measurement performed is of muon neutrino charged current single charged pion production on hydrocarbon in the MINERvA detector and at mean neutrino energy of 6 GeV. The cross section is high statistics, minimally-model dependent, and measured as a function of several muon, pion, and event-wide variables, including the first measurement of the invariant hadronic mass-like variable, "W experimental", in the positive pion channel. Results are compared to the GENIE event generator and found to broadly agree, though outstanding discrepancies remain in low four-momentum transfer squared and in pion kinematics.

 

"My research focus is the fundamental particle called the neutrino.

I have worked on accelerator-based neutrino beams and modeling neutrino beam fluxes, and my current focus as a member of the MINERvA experiment at Fermilab is on neutrino interactions with matter. In particular, I'm measuring neutrino-induced pion production, and I study physics that attempts to model it. My work also serves the exciting area of neutrino oscillations research. Current and upcoming long-baseline oscillation experiments rely on a precise understanding of neutrino interactions in order to advance our research goals.

I'm also interested in science communication, scientific software, and scientific data analysis."

11/2019

Dissertation

Degree

PhD

Graduate Advisor

Vittorio Paolone