Global analysis of neutrino masses, mixings and phases: entering the era of leptonic CP violation searches

We perform a global analysis of neutrino oscillation data, including high-precision measurements of the neutrino mixing angle theta_13 at reactor experiments, which have confirmed previous indications in favor of theta_13>0. Recent data presented at the Neutrino 2012 Conference are also included. We focus on the correlations between theta_13 and the mixing angle theta_23, as well as between theta_13 and the neutrino CP-violation phase delta. We find interesting indications for theta_23< pi/4 and possible hints for delta ~ pi, with no significant difference between normal and inverted mass hierarchy.Comment: Updated version, including recent data released at the Neutrino 2012 Conference. Some references adde

Prospects of accelerator and reactor neutrino oscillation experiments for the coming ten years

We analyze the physics potential of long baseline neutrino oscillation experiments planned for the coming ten years, where the main focus is the sensitivity limit to the small mixing angle $\theta_{13}$. The discussed experiments include the conventional beam experiments MINOS, ICARUS, and OPERA, which are under construction, the planned superbeam experiments J-PARC to Super-Kamiokande and NuMI off-axis, as well as new reactor experiments with near and far detectors, represented by the Double-Chooz project. We perform a complete numerical simulation including systematics, correlations, and degeneracies on an equal footing for all experiments using the GLoBES software. After discussing the improvement of our knowledge on the atmospheric parameters $\theta_{23}$ and $\Delta m^2_{31}$ by these experiments, we investigate the potential to determine $\theta_{13}$ within the next ten years in detail. Furthermore, we show that under optimistic assumptions and for $\theta_{13}$ close to the current bound, even the next generation of experiments might provide some information on the Dirac CP phase and the type of the neutrino mass hierarchy.Comment: 38 pages, 13 figures, Eqs. (1) and (5) corrected, small corrections in Figs. 8, 9, and Tab. 4, discussion improved, ref. added, version to appear in PRD, high resolution figures are available at http://www.sns.ias.edu/~winter/figs0403068.htm

Global fits to neutrino oscillation data

I summarize the determination of neutrino oscillation parameters within the three-flavor framework from world neutrino oscillation data with date of May 2006, including the first results from the MINOS long-baseline experiment. It is illustrated how the determination of the leading "solar" and "atmospheric" parameters, as well as the bound on $\theta_{13}$ emerge from an interplay of various complementary data sets. Furthermore, I discuss possible implications of sub-leading three-flavor effects in present atmospheric neutrino data induced by $\Delta m^2_{21}$ and $\theta_{13}$ for the bound on $\theta_{13}$ and non-maximal values of $\theta_{23}$, emphasizing, however, that these effects are not statistically significant at present. Finally, in view of the upcoming MiniBooNE results I briefly comment on the problem to reconcile the LSND signal.Comment: 5 pages, 5 figures, talk presented at the SNOW2006 workshop, Stockholm, 2-6 May 200

Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters

We present the results of a global neutrino oscillation data analysis within the three-flavour framework. We include latest results from the MINOS long-baseline experiment (including electron neutrino appearance as well as anti-neutrino data), updating all relevant solar (SK II+III), atmospheric (SK I+II+III) and reactor (KamLAND) data. Furthermore, we include a recent re-calculation of the anti-neutrino fluxes emitted from nuclear reactors. These results have important consequences for the analysis of reactor experiments and in particular for the status of the mixing angle $\theta_{13}$. In our recommended default analysis we find from the global fit that the hint for non-zero $\theta_{13}$ remains weak, at 1.8$\sigma$ for both neutrino mass hierarchy schemes. However, we discuss in detail the dependence of these results on assumptions concerning the reactor neutrino analysis.Comment: 15 pages, 10 figures and 2 tables, v2: corrected version, main conclusions unchanged, references adde

Search for hidden-photon dark matter with the FUNK experiment

Many extensions of the Standard Model of particle physics predict a parallel sector of a new U(1) symmetry, giving rise to hidden photons. These hidden photons are candidate particles for cold dark matter. They are expected to kinetically mix with regular photons, which leads to a tiny oscillating electric-field component accompanying dark matter particles. A conducting surface can convert such dark matter particles into photons which are emitted almost perpendicularly to the surface. The corresponding photon frequency follows from the mass of the hidden photons. In this contribution we present a preliminary result on a hidden photon search in the visible and near-UV wavelength range that was done with a large, 14 m2 spherical metallic mirror and discuss future dark matter searches in the eV and sub-eV range by application of different detectors for electromagnetic radiation.Comment: Contribution to the 35th International Cosmic Ray Conference ICRC2017, 10 to 20 July, 2017, Bexco, Busan, Korea. arXiv admin note: text overlap with arXiv:1711.0296

LHC phenomenology of supersymmetric models beyond the MSSM

We discuss various phenomenological aspects of supersymmetric models beyond the MSSM. A particular focus is on models which can correctly explain neutrino data and the possiblities of LHC to identify the underlying scenario.Comment: Contribution to the 16th International Symposium on Particles, Strings and Cosmology (PASCOS 2010), Valencia (Spain), July 19-23, 201

Identifying the Neutrino mass Ordering with INO and NOvA

The relatively large value of $\theta_{13}$ established recently by the Daya Bay reactor experiment opens the possibility to determine the neutrino mass ordering with experiments currently under construction. We investigate synergies between the NOvA long-baseline accelerator experiment with atmospheric neutrino data from the India-based Neutrino Observatory (INO). We identify the requirements on energy and direction reconstruction and detector mass for INO necessary for a significant sensitivity. If neutrino energy and direction reconstruction at the level of 10% and 10 degree can be achieved by INO a determination of the neutrino mass ordering seems possible around 2020.Comment: 18 pages, 8 figures, minor improvements and clarifications, new panel in fig. 7, version to appear in JHEP, typo in eq. 4 correcte

Finite flavour groups of fermions

We present an overview of the theory of finite groups, with regard to their application as flavour symmetries in particle physics. In a general part, we discuss useful theorems concerning group structure, conjugacy classes, representations and character tables. In a specialized part, we attempt to give a fairly comprehensive review of finite subgroups of SO(3) and SU(3), in which we apply and illustrate the general theory. Moreover, we also provide a concise description of the symmetric and alternating groups and comment on the relationship between finite subgroups of U(3) and finite subgroups of SU(3). Though in this review we give a detailed description of a wide range of finite groups, the main focus is on the methods which allow the exploration of their different aspects.Comment: 89 pages, 6 figures, some references added, rearrangement of part of the material, section on SU(3) subgroups substantially extended, some minor revisions. Version for publication in J. Phys. A. Table 12 corrected to match eq.(256), table 14 and eq.(314) corrected to match the 2-dimensional irreps defined on p.6

Solar neutrino-electron scattering as background limitation for double beta decay

The background on double beta decay searches due to elastic electron scattering of solar neutrinos of all double beta emitters with Q-value larger than 2 MeV is calculated, taking into account survival probability and flux uncertainties of solar neutrinos. This work determines the background level to be [1-2]E-7 counts /keV/kg/yr, depending on the precise Q-value of the double beta emitter. It is also shown that the background level increases dramatically if going to lower Q-values. Furthermore, studies are done for various detector systems under consideration for next generation experiments. It was found that experiments based on loaded liquid scintillator have to expect a higher background. Within the given nuclear matrix element uncertainties any approach exploring the normal hierarchy has to face this irreducible background, which is a limitation on the minimal achievable background for purely calorimetric approaches. Large scale liquid scintillator experiments might encounter this problem already while exploring the inverted hierarchy. Potential caveats by using more sophisticated experimental setups are also discussed

Cosmic rays from Leptonic Dark Matter

If dark matter possesses a lepton number, it is natural to expect the dark-matter annihilation and/or decay mainly produces the standard model leptons, while negligible amount of the antiproton is produced. To illustrate such a simple idea, we consider a scenario that a right-handed sneutrino dark matter decays into the standard model particles through tiny R-parity violating interactions. Interestingly enough, charged leptons as well as neutrinos are directly produced, and they can lead to a sharp peak in the predicted positron fraction. Moreover, the decay of the right-handed sneutrino also generates diffuse continuum gamma rays which may account for the excess observed by EGRET, while the primary antiproton flux can be suppressed. Those predictions on the cosmic-ray fluxes of the positrons, gamma rays and antiprotons will be tested by the PAMELA and FGST observatories.Comment: 21 pages, 4 figures, 2 tables, updated plots including PAMELA dat