Three-flavor analysis of long-baseline experiments

We compare the analysis of existing and future neutrino oscillation long-baseline experiments, where we point out that the analysis of future experiments actually implies a 12-dimensional parameter space. Within the three-flavor neutrino oscillation framework, six of these parameters are the fit parameters, and six are the simulated parameters. This high-dimensional parameter space requires the condensation of information and the definition of performance indicators for the purpose needed. As the most sophisticated example for such an indicator, we choose the precision of the leptonic CP phase, and discuss some of the complications of its computation and interpretation.Comment: Talk given at the 6th International Workshop on Neutrino Factories & Superbeams, July 26-Aug 1, 2004, Osaka, Japan. 3 page

Geographical issues and physics applications of "very" long neutrino factory baselines

We discuss several potential applications of ``very'' long neutrino factory baselines, as well as potential detector locations for these applications.Comment: 2 pages, 2 figures; Talk given at the NuFact 05 workshop, June 21-26, Frascati, Ital

Neutrino oscillation physics with a FNAL proton driver

We discuss the need of a proton driver for the Fermilab neutrino oscillation program, as well as its role in the global context.Comment: 3 pages, 1 figure; Talk given at the NuFact 05 workshop, June 21-26, Frascati, Ital

Neutrino Factory Superbeam

We discuss the optimization of a neutrino factory for large \sin^2 2 \theta_{13}, where we assume minimum effort on the accelerator side. This implies that we use low muon energies for the price of an optimized detection system. We demonstrate that such a neutrino factory performs excellent if combined with the electron neutrino appearance channel. Instead of the platinum channel operated with the muon neutrinos from the muon decays, we propose to use the initial superbeam from the decaying pions and kaons, which might be utilized at little extra effort. Since we assume out-of-phase bunches arriving at the same detector, we do not require electron charge identification. In addition, we can choose the proton energy such that we obtain a synergistic spectrum peaking at lower energies. We find that both the superbeam and the neutrino factory beam should used at the identical baseline to reduce matter density uncertainties, possibly with the same detector. This effectively makes the configuration a single experiment, which we call ``neutrino factory superbeam''. We demonstrate that this experiment outperforms a low-energy neutrino factory or a wide band beam alone beyond a simple addition of statistics.Comment: 7 pages, 5 figures, 1 tabl

Neutrino Oscillation Observables from Mass Matrix Structure

We present a systematic procedure to establish a connection between complex neutrino mass matrix textures and experimental observables, including the Dirac CP phase. In addition, we illustrate how future experimental measurements affect the selection of textures in the (theta_13,delta_CP)-plane. For the mixing angles, we use generic assumptions motivated by quark-lepton complementarity. We allow for any combination between U_l and U_nu, as well as we average over all present complex phases. We find that individual textures lead to very different distributions of the observables, such as to large or small leptonic CP violation. In addition, we find that the extended quark-lepton complementarity approach motivates future precision measurements of delta_CP at the level of theta_C \simeq 11 degrees.Comment: Version to appear in Phys. Lett. B. A complete list of textures can be found at http://theorie.physik.uni-wuerzburg.de/~winter/Resources/CTex/index.html . 7 pages, 1 figure, 1 tabl

Neutrino Factories and the "Magic" Baseline

We show that for a neutrino factory baseline of $L \sim 7300 km - 7 600 km$ a ``clean'' measurement of $\sin^2 2 \theta_{13}$ becomes possible, which is almost unaffected by parameter degeneracies. We call this baseline "magic" baseline, because its length only depends on the matter density profile. For a complete analysis, we demonstrate that the combination of the magic baseline with a baseline of 3000 km is the ideal solution to perform equally well for the $\sin^2 2 \theta_{13}$, sign of $\Delta m_{31}^2$, and CP violation sensitivities. Especially, this combination can very successfully resolve parameter degeneracies even below $\sin^2 2 \theta_{13} < 10^{-4}$.Comment: Minor changes, final version to appear in PRD, 4 pages, 3 figures, RevTe

New features in the simulation of neutrino oscillation experiments with GLoBES 3.0

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.Comment: 14 pages, 3 figures, 1 table. Definition of chi2 refined, version to appear in Comput. Phys. Commun. GLoBES software available at http://www.mpi-hd.mpg.de/lin/globes

Direct test of the MSW effect by the solar appearance term in beam experiments

We discuss if one can verify the MSW effect in neutrino oscillations at a high confidence level in long-baseline experiments. We demonstrate that for long enough baselines at neutrino factories, the matter effect sensitivity is, as opposed to the mass hierarchy sensitivity, not suppressed by $\sin^2 2 \theta_{13}$ because it is driven by the solar oscillations in the appearance probability. Furthermore, we show that for the parameter independent direct verification of the MSW effect at long-baseline experiments, a neutrino factory with a baseline of at least 6000 km is needed. For superbeams, we do not find a $5\sigma$ discovery potential of the MSW effect independent of $\sin^2 2 \theta_{13}$. We finally summarize different methods to test the MSW effect.Comment: Minor changes, references updated; somewhat shorter version appeared in Phys. Lett. B; 9 pages, 2 figure

Neutrino tomography - Learning about the Earth's interior using the propagation of neutrinos

Because the propagation of neutrinos is affected by the presence of Earth matter, it opens new possibilities to probe the Earth's interior. Different approaches range from techniques based upon the interaction of high energy (above TeV) neutrinos with Earth matter, to methods using the MSW effect on the neutrino oscillations of low energy (MeV to GeV) neutrinos. In principle, neutrinos from many different sources (sun, atmosphere, supernovae, beams etc.) can be used. In this talk, we summarize and compare different approaches with an emphasis on more recent developments. In addition, we point out other geophysical aspects relevant for neutrino oscillations.Comment: 22 pages, 9 figures. Proceedings of ``Neutrino sciences 2005: Neutrino geophysics'', December 14-16, 2005, Honolulu, USA. Minor changes, some references added. Final version to appear in Earth, Moon, and Planet

The role of matter density uncertainties in the analysis of future neutrino factory experiments

Matter density uncertainties can affect the measurements of the neutrino oscillation parameters at future neutrino factory experiments, such as the measurements of the mixing parameters $\theta_{13}$ and \deltacp. We compare different matter density uncertainty models and discuss the possibility to include the matter density uncertainties in a complete statistical analysis. Furthermore, we systematically study in which measurements and where in the parameter space matter density uncertainties are most relevant. We illustrate this discussion with examples that show the effects as functions of different magnitudes of the matter density uncertainties. We find that matter density uncertainties are especially relevant for large \stheta \gtrsim 10^{-3}. Within the KamLAND-allowed range, they are most relevant for the precision measurements of \stheta and \deltacp, but less relevant for ``binary'' measurements, such as for the sign of \ldm, the sensitivity to \stheta, or the sensitivity to maximal CP violation. In addition, we demonstrate that knowing the matter density along a specific baseline better than to about 1% precision means that all measurements will become almost independent of the matter density uncertainties.Comment: 21 pages, 7 figures, LaTeX. Final version to be published in Phys. Rev.