Antineutrino Neutral Current Interactions in MiniBooNE

Abstract

This dissertation reports the antineutrino-nucleus neutral current elastic scattering cross section on CH 2 measured by the MiniBooNE experiment located in Batavia, IL. The data set consists of 60,605 events passing the selection cuts corresponding to 10.1 × 10 20 POT, which represents the world's largest sample of antineutrino neutral current elastic scattering events.The final sample is more than one order of magnitude lager that the previous antineutrino NCE scattering cross section measurement reported by the BNL E734 experiment. The measurement presented in this dissertation also spans a wider range in Q 2 , including the low-Q 2 regime where the cross section rollover is clearly visible.A χ 2 -based minimization was performed to determine the best value of the axial mass, M A and the Pauli blocking scaling function, κ that matches the antineutrino NCE scattering data. However, the best fit values of M A =1.29 GeV and κ=1.026 still give a relatively poor χ 2 , which suggests that the underlying nuclear model (based largely on the relativistic Fermi gas model) may not be an accurate representation for this particular interaction.Additionally, we present a measurement of the antineutrino/neutrino-nucleus NCE scattering cross section ratio. The neutrino mode NCE sample used in this study, corresponding to 6.4 × 10 20 POT, is also the world's largest sample (also by an order of magnitude). We have demonstrated that the ratio measurement is robust, as most of the correlated errors cancel, as expected. Furthermore, this ratio also proves to be rather insensitive to variations in the axial mass and the Pauli blocking parameter. This is the first time that this ratio has been experimentally reported. We believe this measurement will aid the theoretical physics community to test various model predictions of neutrino-nucleon/nucleus interactions.ii

Probing light dark matter with a hadrophilic scalar mediator

“…This approach has been employed recently by the MiniBooNE-DM collaboration [87][88][89], and the null result from their search in the nucleon elastic scattering channel [87] leads to relevant constraints on our scenario. To estimate the potential dark matter scattering yield and derive the constraints implied by the search [87] we have performed a Monte Carlo simulation using methods similar to those employed in the BdNMC package [85].…”

Progress and open questions in the physics of neutrino cross sections at intermediate energies

“…This becomes evident by looking at the ratio The MiniBooNE experiment performed a detailed study of NC nucleon knock-out on mineral oil (CH 2 ) but their measurement turned out to be rather insensitive to Δs because of difficulties distinguishing between protons and neutrons [29,67]. The recently proposed MiniBooNE+ experiment with improved sensitivity to neutrons might allow a better determination of this important nucleon property [68]. The same is true about MicroBooNE [69], where a reliable identification of the low energy protons knocked out of argon should be possible.…”

Electron ionization via dark matter-electron scattering and the Migdal effect

“…[2] represents sensitivity targets for ELDER DM [69]; points above this curve correspond to SIMP DM models with the same A mediator considered here [70]. Shaded regions represent an envelope of exclusions from beam dump searches (LSND [71], E137 [72,73], and MiniBooNE [74,75]), nuclear recoil direct detection limits from CRESST II [76], and the BaBar monophoton search for invisibly decaying dark photons [77][78][79]. a significant source of systematic uncertainty for Migdal scattering in xenon.…”