Global Analyses of Neutrino Oscillation Experiments

TL;DR

This work surveys the global status of neutrino properties by analyzing solar, atmospheric, reactor, and accelerator data within the three-neutrino paradigm and in extended scenarios. It combines oscillation data into a comprehensive fit for the six $3\nu$ parameters, highlights the mild preference for leptonic CP violation, and assesses the sensitivity to mass ordering and reactor flux systematics. It then explores absolute mass probes, eV-scale sterile neutrinos, and non-standard neutrino interactions, detailing the existing tensions and the resulting constraints. The study underscores the robustness of the $3\nu$ framework while delineating the avenues where new physics—sterile states or NSI—could appear, guiding future experimental and cosmological efforts toward a more complete understanding of neutrino masses and mixing.

Abstract

We summarize the determination of some neutrino properties from the global analysis of solar, atmospheric, reactor, and accelerator neutrino data in the framework of three-neutrino mixing as well as in some extended scenarios such as the mixing with eV-scale sterile neutrinos invoked for the interpretation of the short baseline anomalies, and the presence of non-standard neutrino interactions.

Figures (7)

• Figure 1: Global $3\nu$ oscillation analysis. The red (blue) curves are for Normal (Inverted) Ordering. For solid curves the normalization of reactor fluxes is left free and data from short-baseline (less than 100 m) reactor experiments are included. For dashed curves short-baseline data are not included but reactor fluxes as predicted in Huber:2011wv are assumed. Note that as atmospheric mass-squared splitting we use $\Delta m^2_{31}$ for NO and $\Delta m^2_{32}$ for IO. Figure similar to Fig. 2 in Ref. Gonzalez-Garcia:2014bfa.
• Figure 2: Left:dependence of the global $\Delta\chi^2$ function on the Jarlskog invariant. The red (blue) curves are for NO (IO). Right: leptonic unitarity triangle. After scaling and rotating so that two of its vertices always coincide with $(0,0)$ and $(1,0)$ we plot the $1\sigma$, 90%, $2\sigma$, 99%, $3\sigma$ CL (2 dof) allowed regions of the third vertex.
• Figure 3: 95% allowed regions (for 2 dof) in the planes ($m_{\nu_e}$, $\sum m_\nu$) and ($m_{ee}$, $\sum m_\nu$) obtain from projecting the results of the global analysis of oscillation data.
• Figure 4: Allowed regions at 95% CL (2 dof) for 3+1 oscillations. We show SBL reactor data Declais:1994maKuvshinnikov:1990ryDeclais:1994suVidyakin:1987ueVidyakin:1994utKwon:1981uaZacek:1986cuGreenwood:1996pbAfonin:1988gx (blue shaded), Gallium radioactive source data Hampel:1997fcKaether:2010agAbdurashitov:1998neAbdurashitov:2005tb (orange shaded), $\nu_e$ disappearance constraints from $\nu_e$--$^{12}\text{C}$ scattering data from LSND and KARMEN Auerbach:2001hzArmbruster:1998uk (dark red dotted), long-baseline reactor data from CHOOZ, Palo Verde, DoubleChooz, Daya Bay and RENO (blue short-dashed) and solar+KamLAND data (black long-dashed). The red shaded region is the combined region from all these $\nu_e$ and $\bar{\nu}_e$ disappearance data sets. See Ref. Kopp:2013vaa for details.
• Figure 5: Left: Constraints in the plane of $|U_{\mu 4}|^2$ and $\Delta m^2_{41}$ at 99% CL (2 dof) from CDHS Dydak:1983zq, atmospheric neutrinos Wendell:2010md, MiniBooNE disappearance Cheng:2012yy, MINOS CC and NC data Adamson:2010wiAdamson:2011ku, and the combination of them. In red we show the region preferred by LSND and MiniBooNE appearance data combined with reactor and Gallium data, where for fixed $|U_{\mu 4}|^2$ we minimize with respect to $|U_{e4}|^2$. Right: Comparison of the parameter region preferred by appearance data (LSND Aguilar:2001ty, MiniBooNE appearance analysis AguilarArevalo:2012va, NOMAD Astier:2003gs, KARMEN Armbruster:2002mp, ICARUS Antonello:2012pq, E776 Borodovsky:1992pn) to the exclusion limit from disappearance data (atmospheric, solar, reactors, Gallium, CDHS, MINOS, MiniBooNE disappearance, KARMEN and LSND $\nu_e-^{12}\text{C}$ scattering). See Ref. Kopp:2013vaa for details.