We present the GLoBES ("General Long Baseline Experiment Simulator") software package, which allows the simulation of long-baseline and reactor neutrino oscillation experiments. One part of the software is the abstract experiment definition language to define experiments with beam and full detector descriptions as accurate as possible. Many systematics options are provided, such as normalization and energy calibration errors, or the choice between spectral or total rate information. For the definition of experiments, a new transparent building block concept is introduced. In addition, an additional program provides the possibility to develop and test new experiment definitions quickly. Another part of GLoBES is the user's interface, which provides probability, rate, and ∆χ 2 information for a given experiment or any combination of up to 32 experiments in C. Especially, the ∆χ 2 functions allow a simulation with statistics only, systematics, correlations, and degeneracies. In particular, GLoBES can handle the full multi-parameter correlation among the oscillation parameters, external input, and matter density uncertainties.

We present Version 3.0 of the GLoBES ("General Long Baseline Experiment Simulator") software, which is a simulation tool for short-and long-baseline neutrino oscillation experiments. As a new feature, GLoBES 3.0 allows for user-defined systematical errors, which can also be used to simulate experiments with multiple discrete sources and detectors. In addition, the combination with external information, such as from different experiment classes, is simplified. As far as the probability calculation is concerned, GLoBES now provides an interface for the inclusion of non-standard physics without re-compilation of the software. The set of experiment prototypes coming with GLoBES has been updated. For example, built-in fluxes are now provided for the simulation of beta beams.

We compare the physics potential of planned superbeams with the one of neutrino factories. Therefore, the experimental setups as well as the most relevant uncertainties and errors are considered on the same footing as much as possible. We use an improved analysis including the full parameter correlations, as well as statistical, systematical, and degeneracy errors. Especially, degeneracies have so far not been taken into account in a numerical analysis. We furthermore include external input, such as improved knowledge of the solar oscillation parameters from the KamLAND experiment. This allows us to determine the limiting uncertainties in all cases. For a specific comparison, we choose two representatives of each class: For the superbeam, we take the first conceivable setup, namely the JHF to SuperKamiokande experiment, as well as, on a longer time scale, the JHF to Hyper-Kamiokande experiment. For the neutrino factory, we choose an initially conceivable setup and an advanced machine. We determine the potential to measure the small mixing angle sin 2 2θ 13 , the sign of ∆m 2 31 , and the leptonic CP phase δ CP , which also implies that we compare the limitations of the different setups. We find interesting results, such as the complete loss of the sensitivity to the sign of ∆m 2 31 due to degeneracies in many cases. * Work supported by "Sonderforschungsbereich 375 für Astro-Teilchenphysik" der Deutschen Forschungsgemeinschaft and the "Studienstiftung des deutschen Volkes" (German National Merit Foundation) [W.W.]. a

We present a detailed quantitative discussion of the measurement of the leptonic mixing angle sin 2 2θ 13 with a future reactor neutrino oscillation experiment consisting of a near and far detector. We perform a thorough analysis of the impact of various systematical errors and compare the resulting physics potential to the one of planned first-generation superbeam experiments. Furthermore, we investigate the complementarity of both types of experiments. We find that, under realistic assumptions, a determination of sin 2 2θ 13 down to 10 −2 is possible with reactor experiments. They are thus highly competitive to firstgeneration superbeams and may be able to test sin 2 2θ 13 on shorter timescales. In addition, we find that the combination of a KamLAND-size reactor experiment with one or two superbeams could substantially improve the ability to access the neutrino mass hierarchy or the leptonic CP phase. * Work supported by "Sonderforschungsbereich 375 für Astro-Teilchenphysik" der Deutschen Forschungsgemeinschaft and the "Studienstiftung des deutschen Volkes" (German National Merit Foundation) [W.W.]. a

We review the neutrino flux from gamma-ray bursts, which is estimated from gamma-ray observations and used for the interpretation of recent IceCube data, from a particle physics perspective. We numerically calculate the neutrino flux for the same astrophysical assumptions as the analytical fireball neutrino model, including the dominant pion and kaon production modes, flavor mixing, and magnetic field effects on the secondary muons, pions, and kaons. We demonstrate that taking into account the full energy dependencies of all spectra, the normalization of the expected neutrino flux reduces by about one order of magnitude and the spectrum shifts to higher energies, where we can pin down the exact origin of the discrepancies by the re-computation of the analytical models. We also reproduce the IceCube-40 analysis for exactly the same bursts and same assumptions and illustrate the impact of uncertainties. We conclude that the baryonic loading of the fireballs, which is an important control parameter for the emission of cosmic rays, can be constrained significantly with the full-scale experiment after about ten years.

We discuss simplified models for photo-meson production in cosmic accelerators, such as active galactic nuclei (AGNs) and gamma-ray bursts (GRBs). Our self-consistent models are directly based on the underlying physics used in the SOPHIA software and can be easily adapted if new data are included. They allow for the efficient computation of neutrino and photon spectra (from π 0 decays) as a major requirement of modern time-dependent simulations of the astrophysical sources and parameter studies. In addition, the secondaries (pions and muons) are explicitly generated, a necessity if cooling processes are to be included. For the neutrino production, we include the helicity dependence of the muon decays which in fact leads to larger corrections than the details of the interaction model. The separate computation of the π 0 , π + , and π − fluxes allows, for instance, for flavor ratio predictions of the neutrinos at the source, which are a requirement of many tests of neutrino properties using astrophysical sources. We confirm that for charged pion generation, the often used production by the Δ(1232)-resonance is typically not the dominant process in AGNs and GRBs, and we show, for arbitrary input spectra, that the number of neutrinos are underestimated by at least a factor of two if they are obtained from the neutral-to-charged pion ratio. We compare our results for several levels of simplification using isotropic synchrotron and thermal spectra and demonstrate that they are sufficiently close to the SOPHIA software.

We discuss the optimization of a neutrino factory experiment for neutrino oscillation physics in terms of muon energy, baselines, and oscillation channels (gold, silver, platinum). In addition, we study the impact and requirements for detector technology improvements, and we compare the results to beta beams. We find that the optimized neutrino factory has two baselines, one at about 3000 to 5000 km, the other at about 7500 km ("magic" baseline). The threshold and energy resolution of the golden channel detector have the most promising optimization potential. This, in turn, could be used to lower the muon energy from about 50 GeV to about 20 GeV. Furthermore, the inclusion of electron neutrino appearance with charge identification (platinum channel) could help for large values of sin22theta13. Though tau neutrino appearance with charge identification (silver channel) helps, in principle, to resolve degeneracies for intermediate sin22theta13, we find that alternative strategies may be more feasible in this parameter range. As far as matter density uncertainties are concerned, we demonstrate that their impact can be reduced by the combination of different baselines and channels. Finally, in comparison to beta beams and other alternative technologies, we clearly can establish a superior performance for a neutrino factory in the case sin22theta13<~0.01

We show that for a neutrino factory baseline of Lϳ7 300-7 600 km a ''clean'' measurement of sin 2 2 13 becomes possible, which is almost unaffected by parameter degeneracies. We call this baseline the ''magic'' baseline, because its length depends only on the matter density profile. For a complete analysis, we demonstrate that the combination of the magic baseline with a baseline of 3 000 km is the ideal solution to perform equally well for sin 2 2 13 , the sign of ⌬m 31 2 , and CP violation sensitivities. In particular, this combination can very successfully resolve parameter degeneracies even below sin 2 2 13 Ͻ10 Ϫ4 .