We develop a comprehensive description of three flavor neutrino oscillations inside the Earth in terms of neutrino oscillograms in the whole range of nadir angles and for energies above 0.1 GeV. The effects of the 1-2 mass splitting and mixing as well the interference of the 1-2 and 1-3 modes of oscillations are quantified. The 1-2 mass splitting and mixing lead to the appearance, apart from the resonance MSW peaks, of the parametric resonance peak for core-crossing trajectories at E_nu ~= 0.2 GeV. We show that the interference effects, in particular CP violation, have a domain structure with borders determined by the solar and atmospheric magic lines and the lines of the interference phase condition. The dependence of the oscillograms on the Dirac CP-violating phase is studied. We show that for sin^2(2 theta13) < 0.1 the strongest dependence of the oscillograms on delta is in the 1-2 and 1-3 resonance regions.
The neutrino propagation through the Earth is investigated in the framework of the democratic neutrino theory. In this theory the neutrino mixing angle theta-1-3 is approximately determined, which allows one to make a well defined neutrino oscillogram driven by the 1-3 mixing in the matter of the Earth. Significant differences in this oscillogram from the case of models with relatively small theta-1-3 are discussed.
We describe the effects of neutrino propagation in the matter of the Earth relevant for experiments with atmospheric and accelerator neutrinos and aimed at the determination of the neutrino mass hierarchy and CP-violation. These include (i) the resonance enhancement of neutrino oscillations in matter with constant or nearly constant density, (ii) adiabatic conversion in matter with slowly changing density, (iii) parametric enhancement of oscillations in a multi-layer medium, (iv) oscillations in thin layers of matter. We present the results of semi-analytic descriptions of flavor transitions f…
Electroweak baryogenesis can be driven by the top quark in a general two Higgs doublet model with extra Yukawa couplings. Higgs quartics provide the first order phase transition, while extra top Yukawa coupling $ρ_{tt}$ can fuel the cosmic baryon asymmetry through the $λ_t\,{\rm Im}\,ρ_{tt}$ product, with flavor-changing $ρ_{tc}$ coupling as backup. The impressive ACME 2018 bound on the electron electric dipole moment calls for an extra electron coupling $ρ_{ee}$ for exquisite cancellation among dangerous diagrams, broadening the baryogenesis solution space. The mechanism suggests that extra Y…
Neutrino oscillation experiments in the past decades have greatly improved our knowledge on neutrinos by measuring the fundamental neutrino parameters. The ongoing and upcoming neutrino oscillation experiments are intended to pin down the neutrino mass hierarchy and to discover the leptonic CP violation. By means of neutrino oscillograms, we analyze the impact of non-standard neutrino interactions on neutrino oscillations in the Earth matter. The standard neutrino oscillation probabilities may be significantly changed by non-standard interaction parameters, and in particular, the CP-violating …
Macro-coherent atomic de-excitation involving a neutrino pair emission, radiative emission of neutrino pair (RENP) $|e\rangle \rightarrow |g\rangle + γ+ν_i ν_j$ (with $γ$ a photon and $ν_i$ a neutrino mass eigenstate), is a new experimental tool to determine undetermined neutrino parameters such as the smallest neutrino mass and distinction of Majorana and Dirac neutrinos. The best way to prove that the atomic RENP process accompanied by unseen neutrino pair involves weak interaction is to measure parity violating (PV) quantities. We quantitatively study how this is achieved. The basic mechani…
Flavour oscillations of sub-GeV atmospheric neutrinos and antineutrinos, traversing different distances inside the Earth, are a promising source of information on the leptonic CP phase $δ$. In that energy range, the oscillations are very fast, far beyond the resolution of modern neutrino detectors. However, the necessary averaging over the experimentally typical energy and azimuthal angle bins does not wash out the CP violation effects. In this paper we derive very accurate analytic compact expressions for the averaged oscillations probabilities. Assuming spherically symmetric Earth, the avera…
Multi-megaton scale under ice and underwater detectors of atmospheric neutrinos with few GeV's energy threshold (PINGU, ORCA) open up new possibilities in the determination of neutrino properties, and in particular the neutrino mass hierarchy. With a dense array of optical modules it will be possible to determine the inelasticity, $y$, of the charged current $ν_μ$ events in addition to the neutrino energy $E_ν$ and the muon zenith angle $θ_μ$. The discovery potential of the detectors will substantially increase with the measurement of $y$. It will enable (i) a partial separation of the neutrin…
Neutrino oscillation experiments under neutrino pair beam from circulating excited heavy ions are studied. It is found that detection of double weak events has a good sensitivity to measure CP violating parameter and distinguish mass hierarchy patterns in short baseline experiments in which the earth-induced matter effect is minimized.
We demonstrate that experiments measuring the transition energies of rare-earth ions doped in crystalline lattices are sensitive to violations of Local Lorentz Invariance and Einstein's Equivalence Principle. Using the crystal field of LaCl$_{3}$ as an example, we calculate the frame-dependent energy shifts of the transition frequencies between low-lying states of Ce$^{3+}$, Nd$^{3+}$, and Er$^{3+}$ dopants in the context of the Standard Model Extension, and show that they have high sensitivity to electron anomalies that break rotational invariance.
On 2010 MINOS experiment was showing an hint of possible different mass splitting and mixing angles for neutrinos and anti-neutrinos, suggesting a charge-parity-time (CPT) violation in the lepton sector; last year 2012 a second result from MINOS showed a reduced discrepancy between the two set of parameters, nearly compatible with no CPT violation. We proposed an experiment for more precise estimation of neutrino oscillation parameters being useful not only for a complete discrimination for CPT scenarios, but also for mass hierarchy and theta 13 determination, and mostly for the first oscillat…
Lorentz invariance violation in the extragalactic propagation of ultra-high energy photons and in the development of showers in the Earth crust and atmosphere
Cosmic rays have extremely high particle energies (up to $10^{20} \; \text{eV}$) and can be used to search for violations of Lorentz invariance. We consider isotropic nonbirefringent Lorentz violation in the photon sector for the case of a photon velocity larger than the maximum attainable velocity of the standard fermions. Up to now, Earth-based bounds on this type of Lorentz violation have been determined from observations of TeV gamma rays. Here, we elaborate on a novel approach to test Lorentz invariance with greatly improved sensitivity. This approach is based on investigating extensive a…
Violations of CPT invariance can induce neutrino-to-antineutrino transitions. We study this effect for solar neutrinos and use the upper bound on the solar neutrino-to-antineutrino transition probability from the KamLAND experiment to constrain CPT-symmetry-violating coefficients of the general Standard-Model Extension. The long propagation distance from the Sun to the Earth allows us to improve existing limits by factors ranging from about a thousand to $10^{11}$.
We suggest a new experiment sensitive to a possible difference between the amount of CP violation as measured on the surface of the Earth and in a lower gravity environment. Our proposed experiment is model independent and could yield a $5σ$ measurement within tens of days, indicating a dependence of the level of CP violation in the neutral kaon system on the local gravitational potential.
A MINOS result seemed to hint a different anti-neutrino mass splitting and mixing angle with respect to the neutrino ones, offering a hint for a CPT violation in lepton sector. However more recent MINOS data reduced the neutrino-antineutrino differences leading to a narrow discrepancy almost compatible with no CPT violation, hard to be disentangled. Moreover last a few years of OPERA activity on tau appearance is still un-probed (one unique event). Both flavor muon-tau mixing, tau appearance and eventual CPT violation disentanglement need more tools to be enhanced. Atmospheric muon neutrino sp…
The high-energy astrophysical neutrinos recently discovered by IceCube opened a new way to test Lorentz and CPT violation through the astrophysical neutrino mixing properties. The flavor ratio of astrophysical neutrinos is a very powerful tool to investigate tiny effects caused by Lorentz and CPT violation. There are 3 main findings; (1) current limits on Lorentz and CPT violation in neutrino sector are not tight and they allow for any flavor ratios, (2) however, the observable flavor ratio on the Earth is tied with the flavor ratio at production, this means we can test both the presence of ne…
A brief overview of selected topics in the theory and phenomenology of neutrino oscillations is given. These include: oscillations in vacuum and in matter; phenomenology of 3-flavour neutrino oscillations and effective 2-flavour approximations; CP and T violation in neutrino oscillations in vacuum and in matter; matter effects on ν_μ\leftrightarrow ν_τoscillations; parametric resonance in neutrino oscillations inside the earth; oscillations below and above the MSW resonance; unsettled issues in the theory of neutrino oscillations.
In this talk we cover two threads regarding the 4th generation: on CP violation, from Earth up to the Heavens, i.e. from accelerator-based experimental studies, towards baryon asymmetry of the Universe; and on direct search bounds on $m_{t'}$ and $m_{b'}$, towards the possibility of electroweak symmetry breaking through large Yukawa couplings. Prospects and discussions are presented.
From the data release of OPERA - CNGS experiment, and publicly announced on 23 September 2011, we cast a phenomenological model based on a Majorana neutrino state carrying a fictitious imaginary mass term, already discussed by Majorana in 1932. This mass term can be induced by the interaction with the matter of the Earth's crust during the 735 Km travel. Within the experimental errors, we prove that the model fits with OPERA, MINOS and supernova SN1987a data. Possible violations to Lorentz invariance due to quantum gravity effects have been considered.
The leptonic mixing parameters of high precision and the next-generation neutrino telescopes make it possible to test new physics in the flavor transition of the high-energy astrophysical neutrinos(HAN). We introduce a nonsymmetric matrix to modify the predictions of the standard flavor transition matrix. It is constructed with the mixing matrix in vacuum and that at the source of the HAN. The mismatch of the mixing matrices results in the new expectation of the flavor ratio of the HAN at Earth. It also leads to a secondary effect called the apparent P violation (APV). The quantitative analyse…
This is an extension of the L-2L experiment for measurement of time reversal violation (TRV) proposed in a recent publication. The main new aspects are taking into account the curvature of the earth's surface for long baseline neutrino beams, and recognizing that the matter effects disappear when the baseline is extended. A slight modification of the MINOS project, with a new detector at 2L, is proposed.
NuCraft (nucraft.hepforge.org) is an open-source Python project that calculates neutrino oscillation probabilities for neutrinos from cosmic-ray interactions in the atmosphere for their propagation through Earth. The solution is obtained by numerically solving the Schrödinger equation. The code supports arbitrary numbers of neutrino flavors including additional sterile neutrinos, CP violation, arbitrary mass hierarchies, matter effects with a configurable Earth model, and takes into account the production height distribution of neutrinos in the Earth's atmosphere.
We point out that if the baryon number violating neutron-antineutron oscillation is discovered, it would impose strong limits on the departure from Einstein's equivalence principle at a level of one part in $10^{19}$. If this departure owes its origin to the existence of long-range forces coupled to baryon number $B$ (or $B-L$), it would imply very stringent constraints on the strength of gauge bosons coupling to baryon number current. For instance, if the force mediating baryon number has strength $α_B$ and its range is larger than a megaparsec, we find the limit to be $α_B \leq 2\times 10^{-…
We argue that the detection of neutrino signature from the Earth core is an ideal approach for probing the coupling of heavy dark matter ($m_χ>10^{4}$ GeV) to nucleons. We first note that direct searches for dark matter (DM) in such a mass range do not provide stringent constraints. Furthermore the energies of neutrinos arising from DM annihilations inside the Sun cannot exceed a few TeV at the Sun surface due to the attenuation effect. Therefore the sensitivity to the heavy DM coupling is lost. Finally, the detection of neutrino signature from galactic halo can only probe DM annihilation cros…
Violation of equivalence principle predicts that neutrinos of different flavor couple differently with gravity. Such a scenario can give rise to gravity induced flavor oscillations in addition to the usual mass flavor neutrino oscillations during the neutrino propagation. Even if the equivalence principle is indeed violated, their measure will be extremely small. We explore the possibility to probe the violation of equivalence principle (VEP) for the case of long baseline (LBL) neutrinos in a 4-flavor neutrino framework (3 active + 1 sterile) where both mass and gravity induced oscillations ar…
