A Measurement of $$\nu_e$$ Appearance and $$\nu_\mu$$ Disappearance Neutrino Oscillations with the NOvA Experiment
- Caltech
NOvA is a two-detector, neutrino oscillation experiment on an 810 km baseline in the NuMI beam at Fermilab. NuMI is an off-axis, narrow-band beam centered near 1.8 GeV and is configurable to send a high-purity $$\nu_\mu$$ or $$\bar{\nu}_\mu$$ neutrino flux which passes through the NOvA far detector, sensitive to $$\nu_\mu$$ and $$\bar{\nu}_\mu$$ disappearance and $$\nu_e$$ and $$\bar{\nu}_e$$ appearance. The NOvA near and far detectors are functionally identical, liquid scintillator trackers. They are finely segmented relative to the radiation length in the detectors allowing for the detailed reconstruction of electromagnetic shower necessary to identify $$\nu_e$$ CC events. Through a joint analysis of the appearance and disappearance oscillation channels using neutrino and anti-neutrino data, NOvA constrains the allowed parameter space in $$\delta_{CP}$$, the neutrino mass hierarchy, $$\sin^2\theta_{23}$$, and $$\Delta m^2_{32}$$. We observe 58 and 18 appearance candidates on an expected backgr ound of 15.06 and 5.32 events in neutrino and anti-neutrino mode, respectively. This observation gives a $$1.77\sigma$$ preference for the normal mass hierarchy and $$1.7\sigma$$ preference for $$\theta_{23} > \pi/4$$. NOvA will maintain its position as a long-baseline oscillation experiment with leading sensitivity for several more years in which time analysis will further disambiguate the fundamental neutrino parameters that determine oscillation behavior.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1484186
- Report Number(s):
- FERMILAB-THESIS-2018-17; 1703872
- Country of Publication:
- United States
- Language:
- English
Similar Records
Constraints on neutrino oscillation parameters with the NOvA experiment
Electron Neutrino Appearance in the NO$\nu$A Experiment