Search results for "oscillation"
showing 10 items of 1257 documents
Non-standard neutrino oscillations: perspective from unitarity triangles
2021
We formulate an alternative approach based on unitarity triangles to describe neutrino oscillations in presence of non-standard interactions (NSI). Using perturbation theory, we derive the expression for the oscillation probability in case of NSI and cast it in terms of the three independent parameters of the leptonic unitarity triangle (LUT). The form invariance of the probability expression (even in presence of new physics scenario as long as the mixing matrix is unitary) facilitates a neat geometric view of neutrino oscillations in terms of LUT. We examine the regime of validity of perturbative expansions in the NSI case and make comparisons with approximate expressions existing in liter…
Charged-current neutrino-nucleus scattering off 95,97^Mo
2013
Background: Reliable cross sections for the neutrino-nucleus scattering off relevant nuclei for supernova neutrinos are essential for various applications in neutrino physics and astrophysics (e.g., supernova mechanisms). Studies of the nuclear responses for the stable molybdenum isotopes are of great interest for the planned MOON (Mo Observatory of Neutrinos) experiment.Purpose: The purpose of the present work is, thus, to perform a detailed study of the charged-current nuclear responses to supernova neutrinos for the stable odd molybdenum isotopes. A special effort will be devoted to discuss in detail the structures of the most relevant final states in the corresponding proton-odd nucleus…
Neutron-Tagging with Hydrogen in Super-Kamiokande IV: Global Atmospheric Neutrino Oscillation Analysis with SK
2018
Currently, SK has the capability of tag neutrons through hydrogen-neutron captures. This technique is around four times less efficient than in the proposed SuperK, Gd, i.e. \(\sim \)20%. However, it is enough for seen the relevance of the improvements, brought by neutron tagging, in the atmospheric oscillation analysis.
Neutrino oscillation physics with a higher-γ β-beam
2004
The precision measurement and discovery potential of a neutrino factory based on boosted radioactive ions in a storage ring (“β-beam”) is re-examined. In contrast with past designs, which assume ion γ factors of ∼100 and baselines of L=130 km, we emphasize the advantages of boosting the ions to higher γ and increasing the baseline proportionally. In particular, we consider a “medium-γ” scenario (γ∼500, L∼730 km) and a “high-γ” scenario (γ∼2000, L∼3000 km). The increase in statistics, which grow linearly with the average beam energy, the ability to exploit the energy dependence of the signal and the sizable matter effects at this longer baseline all increase the discovery potential of such a…
Reactor neutrino background at the proposed LAGUNA sites
2012
Abstract The electron antineutrino background from reactors is estimated in proposed LAGUNA sites using commercial fission reactors operational in 2009. Calculations are made for an input to background studies like e.g. geoneutrino measurement uncertainty estimation.
Only three flavours
1998
Abstract It is shown that it is possible to account for all the experimental indications for neutrino oscillations with just three flavours. In particular we suggest that the atmospheric neutrino anomaly and the LSND result can be explained by the same mass difference and mixing. Possible implications and future test of the resulting mass and mixing pattern are given.
Updated T2K measurements of muon neutrino and antineutrino disappearance using 1.5×1021 protons on target
2017
We report measurements by the T2K experiment of the parameters $\theta_{23}$ and $\Delta m^{2}_{32}$ governing the disappearance of muon neutrinos and antineutrinos in the three flavor neutrino oscillation model. Utilizing the ability of the experiment to run with either a mainly neutrino or a mainly antineutrino beam, the parameters are measured separately for neutrinos and antineutrinos. Using $7.482 \times 10^{20}$ POT in neutrino running mode and $7.471 \times 10^{20}$ POT in antineutrino mode, T2K obtained, $\sin^{2}(\theta_{23})=0.51^{+0.08}_{-0.07}$ and $\Delta m^{2}_{32} = 2.53^{+0.15}_{-0.13} \times 10^{-3}$eV$^{2}$/c$^{4}$ for neutrinos, and $\sin^{2}({\overline{\theta}}_{23})=0.4…
The dynamics of the electron in a homonuclear driven molecular ion
2004
Abstract The radiation diffused by a one-dimensional homonuclear molecular ion driven by a laser field is studied as a function of the time. When the photon energy is resonant with the energy gap between the ground and the first excited state, the electronic probability density is seen to undergo slow and deep oscillations between the two nuclei. Synchronous to such oscillations, deep modulations of the emitted power are observed. The period of oscillation is of the order of 10 optical cycles. Detection of the variation in the intensity of the emitted electromagnetic spectrum therefore brings information on the position of the electron in the molecule.
Discovery of a Transition to Global Spin-up in EXO 2030+375
2005
EXO 2030+375, a 42-second transient X-ray pulsar with a Be star companion, has been observed to undergo an outburst at nearly every periastron passage for the last 13.5 years. From 1994 through 2002, the global trend in the pulsar spin frequency was spin-down. Using RXTE data from 2003 September, we have observed a transition to global spin-up in EXO 2030+375. Although the spin frequency observations are sparse, the relative spin-up between 2002 June and 2003 September observations, along with an overall brightening of the outbursts since mid 2002 observed with the RXTE ASM, accompanied by an increase in density of the Be disk, indicated by infrared magnitudes, suggest that the pattern obse…
Individual and center-of-mass resonances in the motional spectrum of an electron cloud in a Penning trap
2002
We have examined experimentally the motional spectrum of an electron cloud confined in a Penning trap. When the axial oscillation is excited by a radio frequency field the resonance exhibits a double structure. Both components depend differently on the number of trapped electrons and have different shape and width. We conclude that one of them corresponds to the excitation of the individual electrons while the other is the center-of-mass mode of the cloud. The threshold behaviour of the center-of-mass resonance suggests that it is a parametric instability of a Mathieu type equation of motion.