Constraints on Oscillation Parameters from ν_e Appearance and ν_μ Disappearance in NOvA
Results are reported from an improved measurement of ν_μ→ν_e transitions by the NOvA experiment. Using an exposure equivalent to 6.05×10^(20) protons on target, 33 ν_e candidates are observed with a background of 8.2±0.8 (syst.). Combined with the latest NOvA ν_μ disappearance data and external constraints from reactor experiments on sin^2 2θ_(13), the hypothesis of inverted mass hierarchy with θ_(23) in the lower octant is disfavored at greater than 93% C.L. for all values of δ_(CP).
© 2017 American Physical Society. Received 10 March 2017; revised manuscript received 9 May 2017; published 5 June 2017. This work was supported by the U.S. Department of Energy; the U.S. National Science Foundation; the Department of Science and Technology, India; the European Research Council; the MSMT CR, GA UK, Czech Republic; the RAS, RMES, and RFBR, Russia; CNPq and FAPEG, Brazil; and the State and University of Minnesota. We are grateful for the contributions of the staffs at the University of Minnesota module assembly facility and Ash River Laboratory, Argonne National Laboratory, and Fermilab. Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the U.S. DOE.
Submitted - 1703.03328.pdf
Published - PhysRevLett.118.231801.pdf