MiniBooNE

The physics motivations, design, and status of the Booster Neutrino Experiment at Fermilab, MiniBooNE, are briefly discussed. Particular emphasis is given on the ongoing preparatory work that is needed for the MiniBooNE muon neutrino to electron neutrino oscillation appearance search. This search aims to confirm or refute in a definitive and independent way the evidence for neutrino oscillations reported by the LSND experiment.Comment: 3 pages, no figures, to appear in the proceedings of the 9th International Conference on Astroparticle and Underground Physics (TAUP 2005), Zaragoza, Spain, 10-14 Sep 200

Phased Locked Laser Diode by Using Passive Array of Multi-Mode Interference Couplers

We report a phase locked laser diode based on a passive array of 1×2 multi-mode interference couplers and quantum well intermixing techniques which shows stable and clear coherence far field patters from both active and passive side up to at least 9 times threshold current

Implications of Confirmation of the LSND anti-nu_mu -> anti-nu_e Oscillation Signal

Neutrino oscillations have been observed in solar and atmospheric neutrinos, and in the LSND accelerator experiment. The Standard Model cannot accommodate all three positive results. The solar and atmospheric results have been confirmed. An oscillation signal seen by MiniBooNE will validate the oscillation signal seen by LSND. The question then becomes one of refining the Standard Model to allow for these three results. Four theories which can accommodate all three oscillation observations are the existence of sterile neutrinos, CP violation, the existence of variable mass neutrinos, and small Lorentz violations. The Spallation Neutron Source (SNS), located at Oak Ridge Laboratories, Oak Ridge, Tennessee, will provide an ideal site to test these hypotheses. The SNS, due to turn on in 2008, will supply a high intensity neutrino source of known flux and energy spectrum. This source permits experiments to probe the high delta-m^2 region for measurements, where a positive signal from MiniBooNE would lie.Comment: 3 pages. Proceedings for talk presented at the 6th International Workshop of Neutrino Factories and Superbemans (NuFact04). Proceedings will be published as a supplement to Nuclear Physics

Cosmo MSW effect for mass varying neutrinos

We consider neutrinos with varying masses which arise in scenarios relating neutrino masses to the dark energy density in the universe. We point out that the neutrino mass variation can lead to level crossing and thus a cosmo MSW effect, having dramatic consequences for the flavor ratio of astrophysical neutrinos.Comment: 8 pages, 1 figure, more detailed discussions, version to be published by Mod. Phys. Lett.

Leptonic CP violation studies at MiniBooNE in the (3+2) sterile neutrino oscillation hypothesis

We investigate the extent to which leptonic CP-violation in (3+2) sterile neutrino models leads to different oscillation probabilities for $\bar{\nu}_{\mu}\to\bar{\nu}_e$ and $\nu_{\mu}\to\nu_e$ oscillations at MiniBooNE. We are using a combined analysis of short-baseline (SBL) oscillation results, including the LSND and null SBL results, to which we impose additional constraints from atmospheric oscillation data. We obtain the favored regions in MiniBooNE oscillation probability space for both (3+2) CP-conserving and (3+2) CP-violating models. We further investigate the allowed CP-violation phase values and the MiniBooNE reach for such a CP violation measurement. The analysis shows that the oscillation probabilities in MiniBooNE neutrino and antineutrino running modes can differ significantly, with the latter possibly being as much as three times larger than the first. In addition, we also show that all possible values of the single CP-violation phase measurable at short baselines in (3+2) models are allowed within 99% CL by existing data.Comment: Fixed a typo following PRD Erratum. 8 pages, 5 figure

Explaining LSND by a decaying sterile neutrino

We propose an explanation of the LSND evidence for electron antineutrino appearance based on neutrino decay. We introduce a heavy neutrino, which is produced in pion and muon decays because of a small mixing with muon neutrinos, and then decays into a scalar particle and a light neutrino, predominantly of the electron type. We require values of $g m_4\sim$ few eV, $g$ being the neutrino--scalar coupling and $m_4$ the heavy neutrino mass, e.g. $m_4$ in the range from 1 keV to 1 MeV and $g \sim 10^{-6} - 10^{-3}$. Performing a fit to the LSND data as well as all relevant null-result experiments, we show that all data can be explained within this decay scenario. In the minimal version of the decay model, we predict a signal in the upcoming MiniBooNE experiment corresponding to a transition probability of the same order as seen in LSND. In addition, we show that extending our model to two nearly degenerate heavy neutrinos it is possible to introduce CP violation in the decay, which can lead to a suppression of the signal in MiniBooNE running in the neutrino mode. We briefly discuss signals in future neutrino oscillation experiments, we show that our scenario is compatible with bounds from laboratory experiments, and we comment on implications in astrophysics and cosmology.Comment: 23 pages, 5 figures, minor improvements, matches published versio

The Future of Neutrino Mass Measurements: Terrestrial, Astrophysical, and Cosmological Measurements in the Next Decade. Highlights of the NuMass 2013 Workshop. Milano, Italy, February 4 - 7, 2013

The third Workshop of the NuMass series ("The Future of Neutrino Mass Measurements: Terrestrial, Astrophysical, and Cosmological Measurements in the Next Decade: NuMass 2013") was held at Dipartimento di Fisica "G. Occhialini, University of Milano-Bicocca in Milano, Italy, on 4-7 February 2013. The goal of this international workshop was to review the status and future of direct and indirect neutrino mass measurements in the laboratory as well as from astrophysical and cosmological observations. This paper collects most of the contributions presented during the Workshop

Modeling Resolution of Resources Contention in Synchronous Data Flow Graphs

Synchronous Data Flow graphs are widely adopted in the designing of streaming applications, but were originally formulated to describe only how an application is partitioned and which data are exchanged among different tasks. Since Synchronous Data Flow graphs are often used to describe and evaluate complete design solutions, missing information (e.g., mapping, scheduling, etc.) has to be included in them by means of further actors and channels to obtain accurate evaluations. To address this issue preserving the simplicity of the representation, techniques that model data transfer delays by means of ad-hoc actors have been proposed, but they model independently each communication ignoring contentions. Moreover, they do not usually consider at all delays due to buffer contentions, potentially overestimating the throughput of a design solution. In this paper a technique to extend Synchronous Data Flow graphs by adding ad-hoc actors and channels to model resolution of resources contentions is proposed. The results show that the number of added actors and channels is limited but that they can significantly increase the Synchronous Data Flow graph accuracy

A combined analysis of short-baseline neutrino experiments in the (3+1) and (3+2) sterile neutrino oscillation hypotheses

We investigate adding two sterile neutrinos to resolve the apparent tension existing between short-baseline neutrino oscillation results and CPT-conserving, four-neutrino oscillation models. For both (3+1) and (3+2) models, the level of statistical compatibility between the combined dataset from the null short-baseline experiments Bugey, CHOOZ, CCFR84, CDHS, KARMEN, and NOMAD, on the one hand; and the LSND dataset, on the other, is computed. A combined analysis of all seven short-baseline experiments, including LSND, is also performed, to obtain the favored regions in neutrino mass and mixing parameter space for both models. Finally, four statistical tests to compare the (3+1) and the (3+2) hypotheses are discussed. All tests show that (3+2) models fit the existing short-baseline data significantly better than (3+1) models.Comment: 16 pages, 15 figures. Added NOMAD data to the analysis, one statistical test, and two figures. References and text added. Version submitted to PR