Search results for "Instrumentation"
showing 10 items of 4914 documents
Global analysis of neutrino oscillation data in four-neutrino schemes
2002
We present an analysis of the global neutrino oscillation data in terms of four-neutrino mass schemes. We find that the strong preference of oscillations into active neutrinos implied by the latest solar as well as atmospheric neutrino data allows to rule out (2+2) mass schemes, whereas (3+1) schemes are strongly disfavoured by short-baseline experiments. Our analysis shows that four-neutrino oscillations do not provide a satisfactory description of the global neutrino oscillation data including the LSND result.
Probing supernova physics with neutrino oscillations
2001
We point out that solar neutrino oscillations with large mixing angle as evidenced in current solar neutrino data have a strong impact on strategies for diagnosing collapse-driven supernova (SN) through neutrino observations. Such oscillations induce a significant deformation of the energy spectra of neutrinos, thereby allowing us to obtain otherwise inaccessible features of SN neutrino spectra. We demonstrate that one can determine temperatures and luminosities of non-electron flavor neutrinos by observing bar{nu}_{e} from galactic SN in massive water Cherenkov detectors by the charged current reactions on protons.
Working group on neutrino physics and astrophysics — concluding remarks I
1998
Abstract This part of the concluding remarks on the contributions and discussions in the working group on Neutrino Physics and Astrophysics summarises the following items: 1. 1) Neutrino mass measurement from Tritium beta decay, 2. 2) Neutrinoless double beta decay, 3. 3) Application of cryodetectors to the determination of neutrino properties, 4. 4) Search for a magnetic moment of the neutrino and, 5. 5) Limits on the mass of the Tau neutrino
Fitting Simpson's neutrino into the standard model
1985
Abstract I show how to accomodate the 17 keV state recently reported by Simpson as one of the neutrinos of the standard model. Experimental constraints can only be satisfied if the μ and τ neutrino combine to a very good approximation to form a Dirac neutrino of 17 keV leaving a light ν e . Neutrino oscillations will provide the most stringent test of the model. The cosmological bounds are also satisfied in a natural way in models with Goldstone bosons. Explicit examples are given in the framework of majoron-type models. Constraints on the lepton symmetry breaking scale which follow from astrophysics, cosmology and laboratory experiments are discussed.
Neutrinos as the messengers of CPT violation
2001
CPT violation has the potential to explain all three existing neutrino anomalies without enlarging the neutrino sector. CPT violation in the Dirac mass terms of the three neutrino flavors preserves Lorentz invariance, but generates independent masses for neutrinos and antineutrinos. This specific signature is strongly motivated by braneworld scenarios with extra dimensions, where neutrinos are the natural messengers for Standard Model physics of CPT violation in the bulk. A simple model of maximal CPT violation is sufficient to explain the exisiting neutrino data quite neatly, while making dramatic predictions for the upcoming KamLAND and MiniBooNE experiments. Furthermore we obtain a promi…
The KATRIN sensitivity to the neutrino mass and to right-handed currents in beta decay
2007
The aim of the KArlsruhe TRItium Neutrino experiment KATRIN is the determination of the absolute neutrino mass scale down to 0.2 eV, with essentially smaller model dependence than from cosmology and neutrinoless double beta decay. For this purpose, the integral electron energy spectrum is measured close to the endpoint of molecular tritium beta decay. The endpoint, together with the neutrino mass, should be fitted from the KATRIN data as a free parameter. The right-handed couplings change the electron energy spectrum close to the endpoint, therefore they have some effect also to the precise neutrino mass determination. The statistical calculations show that, using the endpoint as a free par…
Confusing non-standard neutrino interactions with oscillations at a neutrino factory
2002
Most neutrino mass theories contain non-standard interactions (NSI) of neutrinos which can be either non-universal (NU) or flavor-changing (FC). We study the impact of such interactions on the determination of neutrino mixing parameters at a neutrino factory using the so-called ``golden channels'' \pnu{e}\to\pnu{\mu} for the measurement of \theta_{13}. We show that a certain combination of FC interactions in neutrino source and earth matter can give exactly the same signal as oscillations arising due to \theta_{13}. This implies that information about \theta_{13} can only be obtained if bounds on NSI are available. Taking into account the existing bounds on FC interactions, this leads to a …
Superbeam studies at CERN
2003
Abstract A conventional low-energy neutrino beam of great intensity could be produced by the Super Proton Linac at CERN as a first stage of a Neutrino Factory. Water Cherenkov and liquid scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve our current knowledge of the atmospheric parameters Δmatm2, θ23 and measure or severely constrain θ13. It is also shown that a very large water detector could eventually observe leptonic CP violation.
Can OPERA help in constraining neutrino non-standard interactions?
2008
We study how much the unique ability of the OPERA experiment to directly detect \nu_\tau can help in probing new, non-standard contact interactions of the third family of neutrinos. We perform a combined analysis of future, high-statistics MINOS and OPERA data. For the case of non-standard interactions in \nu_\mu to \nu_e transitions we also include the impact of possible DoubleCHOOZ data. In all cases we find that the \nu_\tau sample of OPERA is too small to be statistically significant, even if one doubles the nominal exposure of OPERA to 4.5E20 pot. OPERA's real benefit for this measurement lies in its very high neutrino energy and hence very different L/E compared to MINOS.
Physics of Massive Neutrinos
2004
I summarize the present status of global analyses of neutrino oscillations, including the most recent KamLAND and K2K data, as well as the latest solar and atmospheric neutrino fluxes. I give the allowed ranges of the three--flavour oscillation parameters from the current worlds' global neutrino data sample, their best fit values and discuss the small parameters DeltaM_solar/DeltaM_atm and sin^2 theta_13, which characterize the strength of CP violation in neutrino oscillations. I briefly discuss neutrinoless double beta decay and the LSND neutrino oscillation hint, as well as the robustness of the neutrino oscillation results in the presence of non-standard physics.