Removal Energies and Final State Interaction in Lepton Nucleus Scattering

We investigate the binding energy parameters that should be used in modeling electron and neutrino scattering from nucleons bound in a nucleus within the framework of the impulse approximation. We discuss the relation between binding energy, missing energy, removal energy ($\epsilon$), spectral functions and shell model energy levels and extract updated removal energy parameters from ee$^{\prime}$p spectral function data. We address the difference in parameters for scattering from bound protons and neutrons. We also use inclusive e-A data to extract an empirical parameter $U_{FSI}( (\vec q_3+\vec k)^2)$ to account for the interaction of final state nucleons (FSI) with the optical potential of the nucleus. Similarly we use $V_{eff}$ to account for the Coulomb potential of the nucleus. With three parameters $\epsilon$, $U_{FSI}( (\vec q_3+\vec k)^2)$ and $V_{eff}$ we can describe the energy of final state electrons for all available electron QE scattering data. The use of the updated parameters in neutrino Monte Carlo generators reduces the systematic uncertainty in the combined removal energy (with FSI corrections) from $\pm$ 20 MeV to $\pm$ 5 MeV.Comment: 21 pages, 22 Figures, 11 Tables, Accepted for publication in Eur. Phys. J. C. 2019, all fits to Optical potential redone with respect to (q3+k)^

Comparison of optical potential for nucleons and Δ\Delta resonances

Precise modeling of neutrino interactions on nuclear targets is essential for neutrino oscillations experiments. The modeling of the energy of final state particles in quasielastic (QE) scattering and resonance production on bound nucleons requires knowledge of both the removal energy of the initial state bound nucleon as well as the average Coulomb and nuclear optical potentials for final state leptons and hadrons. We extract the average values of the real part of the nuclear optical potential for final state nucleons ($U_{opt}^{QE}$) as a function of the nucleon kinetic energy from inclusive electron scattering data on nuclear targets ($\bf_{6}^{12}C$+$\bf_{8}^{16}O$, $\bf_{20}^{40}Ca$+$\bf_{18}^{40}Ar$, $\bf_{3}^{6}Li$, $\bf_{18}^{27}Al$, $\bf_{26}^{56}Fe$, $\bf_{82}^{208}Pb$) in the QE region and compare to calculations. We also extract values of the average of the real part of the nuclear optical potential for a $\Delta(1232)$ resonance in the final state ($U^\Delta_{opt}$) within the impulse approximation. We find that $U^\Delta_{opt}$ is more negative than $U_{opt}^{QE}$ with $U^\Delta_{opt}\approx$1.5~$U_{opt}^{QE}$ for $\bf_{6}^{12}C$.Comment: 15 pages, 11 figures, 2 tables. Version 5 as published in Eur. Phys. Journal C 202

Accelerating Machine Learning Inference with GPUs in ProtoDUNE Data Processing

We study the performance of a cloud-based GPU-accelerated inference server to speed up event reconstruction in neutrino data batch jobs. Using detector data from the ProtoDUNE experiment and employing the standard DUNE grid job submission tools, we attempt to reprocess the data by running several thousand concurrent grid jobs, a rate we expect to be typical of current and future neutrino physics experiments. We process most of the dataset with the GPU version of our processing algorithm and the remainder with the CPU version for timing comparisons. We find that a 100-GPU cloud-based server is able to easily meet the processing demand, and that using the GPU version of the event processing algorithm is two times faster than processing these data with the CPU version when comparing to the newest CPUs in our sample. The amount of data transferred to the inference server during the GPU runs can overwhelm even the highest-bandwidth network switches, however, unless care is taken to observe network facility limits or otherwise distribute the jobs to multiple sites. We discuss the lessons learned from this processing campaign and several avenues for future improvements.Comment: 13 pages, 9 figures, matches accepted versio

Comparison of optical potential for nucleons and Δ\varDelta resonances

AbstractPrecise modeling of neutrino interactions on nuclear targets is essential for neutrino oscillations experiments. The modeling of the energy of final state particles in quasielastic (QE) scattering and resonance production on bound nucleons requires knowledge of both the removal energy of the initial state bound nucleon as well as the average Coulomb and nuclear optical potentials for final state leptons and hadrons. We extract the average values of the real part of the nuclear optical potential for final state nucleons ($$U_{opt}^{QE}$$UoptQE) as a function of the nucleon kinetic energy from inclusive electron scattering data on nuclear targets ($$_\mathbf{6 }^\mathbf{12 }{} \mathbf{C}$$612C+$$_\mathbf{8 }^\mathbf{16 }{} \mathbf{O}$$816O, $$_\mathbf{20 }^\mathbf{40 }{} \mathbf{Ca}$$2040Ca+$$_\mathbf{18 }^\mathbf{40 }{} \mathbf{Ar}$$1840Ar, $$_\mathbf{3 }^\mathbf{6 }{} \mathbf{Li}$$36Li, $$_\mathbf{18 }^\mathbf{27 }{} \mathbf{Al}$$1827Al, $$_\mathbf{26 }^\mathbf{56 }{} \mathbf{Fe}$$2656Fe, $$_\mathbf{82 }^\mathbf{208 }{} \mathbf{Pb}$$82208Pb) in the QE region and compare to calculations. We also extract values of the average of the real part of the nuclear optical potential for a $$\varDelta (1232)$$Δ(1232) resonance in the final state ($$U^\varDelta _{opt}$$UoptΔ) within the impulse approximation. We find that $$U^\varDelta _{opt}$$UoptΔ is more negative than $$U_{opt}^{QE}$$UoptQE with $$U^\varDelta _{opt}\approx$$UoptΔ≈1.5 $$U_{opt}^{QE}$$UoptQE for $$_\mathbf{6 }^\mathbf{12 }{} \mathbf{C}$$612C.</jats:p

Measurements of nuclear effects and the v̄µ + H → µ+ + n cross section in MINERνA with neutron tagging

Thesis (Ph. D.)--University of Rochester. Department of Physics and Astronomy, 2021.MINERνA, or Main INjector ExpeRiment for ν-A, at Fermilab, is an experiment dedicated to the study of neutrino-nucleus interactions in the GeV regime. Its goal is to illustrate the interplay between hadronic and nuclear physics and measure intranuclear dynamics crucial for the present and future neutrino oscillation measurements. We first measure a set of variables sensitive to how Monte Carlo (MC) simulations of neutrino-nucleus interactions implement binding energy and then move on to measure the antineutrino CCQE cross section on the hydrogen targets in MINERνA’s CH detector. We have developed a method to preferentially select events on the hydrogen by comparing outgoing neutrons’ directions to theoretical neutron directions assuming two-body interactions. We measured the cross section, extracted the axial form factor, and performed a Z-expansion fit. We observe larger values in the axial form factor at high Q2 than current best fits. Finally, we show a preliminary selection of events with both protons and neutrons to investigate nuclear processes responsible for producing these final states