Search results for " Oscillation"

Neutrino Spin Oscillations in External Gravitational Fields

2007

Predictive flavor symmetries of the neutrino mass matrix.

2007

Here we propose an $A_4$ flavour symmetry model which implies a lower bound on the neutrinoless double beta decay rate, corresponding to an effective mass parameter $M_{ee} \gsim 0.03$ eV, and a direct correlation between the expected magnitude of CP violation in neutrino oscillations and the value of $\sin^2\theta_{13}$, as well as a nearly maximal CP phase $\delta$.

Disentangling genuine from matter-induced CP violation in neutrino oscillations

2018

We prove that, in any flavor transition, neutrino oscillation CP violating asymmetries in matter have two disentangled components: (a) a CPT-odd T-invariant term, non-vanishing iff there are interactions with matter; (b) a T-odd CPT-invariant term, non-vanishing iff there is genuine CP violation. As function of the baseline, these two terms are distinct L-even and L-odd observables, respectively. In the experimental region of terrestrial accelerator neutrinos, we calculate their approximate expressions from which we prove that, at medium baselines, the CPT-odd component is small and nearly $\delta$-independent, so it can be subtracted from the experimental CP asymmetry as a theoretical back…

Neutrino mass in supersymmetry

2009

10 páginas, 8 figuras.-- El PDF es la versión pre-print (arXiv:0911.3103v1).-- Trabajo presentado al SUSY09: 7th International Conference on Supersymmetry and the Unification of Fundamental Interactions.

Physics potential of beta/EC beams in regard to CP violation in neutrino oscillations

2007

The goal for future neutrino facilities is the determination of the [Ue3] mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source. With this objective the creation of neutrino beams from the radioactive decay of boosted ions by the SPS of CERN from either beta or electron capture transitions has been propossed. We discuss the capabilities of such facilities as a function of the energy of the boost and the baseline for the detector. We conclude that the SPS upgrade to 1000 GeV is crucial to have a better sensitivity to CP violation if it is accompanied by a longer baseline. We compare the physics potential for two differen…

Constraining the neutrino magnetic moment with anti-neutrinos from the Sun

2003

We discuss the impact of different solar neutrino data on the spin-flavor-precession (SFP) mechanism of neutrino conversion. We find that, although detailed solar rates and spectra allow the SFP solution as a sub-leading effect, the recent KamLAND constraint on the solar antineutrino flux places stronger constraints to this mechanism. Moreover, we show that for the case of random magnetic fields inside the Sun, one obtains a more stringent constraint on the neutrino magnetic moment down to the level of \mu_\nu \lsim few \times 10^{-12}\mu_B, similar to bounds obtained from star cooling.

Neutrinos in Nuclear Physics: RPA, MEC, 2p2h (Pionic Modes of Excitation in Nuclei)

2016

This chapter is devoted to the study of weak interactions on nucleons and nuclei. I pay a special attention to the study of neutrino and antineutrino quasi-elastic reactions in nuclei , which are of the greatest importance for neutrino oscillation experiments, and crucial to achieve the precision goals required to make new discoveries, like the CP violation in the leptonic sector, possible. In particular, I discuss RPA correlations and 2p2h (multi-nucleon) effects on charged-current neutrino-nucleus reactions, and the influence of these nuclear effects on the recently measured MiniBooNE flux folded differential cross sections, and on the so-called nucleon axial mass puzzle. The modification…

Supersymmetric majoron signatures and solar neutrino oscillations

1988

Spontaneous R-parity breaking in supergravity solves the solar neutrino problem through matter-enhanced neutrino oscillations. The model may be tested in collider experiments and through ``dynamical'' effects associated with the existence of a weakly interacting majoron. Apart from astrophysical effects, majoron emission can produce observable changes in \ensuremath{\mu} and \ensuremath{\tau} decay spectra for parameter values that substantially reduce the solar neutrino flux. A signature of the model is the possible observation of the decay \ensuremath{\mu}\ensuremath{\rightarrow}e+majoron.

Determination of the $\theta_{23}$ octant in LBNO

2014

According to the recent results of the neutrino oscillation experiment MINOS, the neutrino mixing angle $\theta_{23}$ may not be maximal ($45^{\circ}$). Two nearly degenerate solutions are possible, one in the lower octant (LO) where $\theta_{23}45^{\circ}$. Long baseline experiments measuring the $\nu_{\mu}\rightarrow\nu_{e}$ are capable of resolving this degeneracy. In this work we study the potential of the planned European LBNO experiment to distinguish between the LO and HO solutions.

Neutrino oscillations and the seesaw origin of neutrino mass

2016

The historical discovery of neutrino oscillations using solar and atmospheric neutrinos, and subsequent accelerator and reactor studies, has brought neutrino physics to the precision era. We note that CP effects in oscillation phenomena could be difficult to extract in the presence of unitarity violation. As a result upcoming dedicated leptonic CP violation studies should take into account the non-unitarity of the lepton mixing matrix. Restricting non-unitarity will shed light on the seesaw scale, and thereby guide us towards the new physics responsible for neutrino mass generation.