scholarly journals Residual Symmetries Applied to Neutrino Oscillations at NOνA and T2K

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Andrew D. Hanlon ◽  
Wayne W. Repko ◽  
Duane A. Dicus

The results previously obtained from the model-independent application of a generalized hidden horizontalZ2symmetry to the neutrino mass matrix are updated using the latest global fits for the neutrino oscillation parameters. The resulting prediction for the DiracCPphaseδDis in agreement with recent results from T2K. The distribution for the Jarlskog invariantJνhas become sharper and appears to be approaching a particular region. The approximate effects of matter on long-baseline neutrino experiments are explored, and it is shown how the weak interactions between the neutrinos and the particles that make up the Earth can help to determine the mass hierarchy. A similar strategy is employed to show how NOνA and T2K could determine the octant ofθa(≡θ23). Finally, the exact effects of matter are obtained numerically in order to make comparisons with the form of the approximate solutions. From this analysis there emerge some interesting features of the effective mass eigenvalues.

2016 ◽  
Vol 31 (04n05) ◽  
pp. 1650002
Author(s):  
Debasish Borah

We revisit the possibility of relating lepton mixing angles with lepton mass hierarchies in a model-independent way. Guided by the existence of such relations in the quark sector, we first consider all the mixing angles, both in charged lepton and neutrino sectors to be related to the respective mass ratios. This allows us to calculate the leptonic mixing angles observed in neutrino oscillations as functions of the lightest neutrino mass. We show that for both normal and inverted hierarchical neutrino masses, this scenario does not give rise to correct leptonic mixing angles. We then show that correct leptonic mixing angles can be generated with normal hierarchical neutrino masses if the relation between mixing angle and mass ratio is restricted to 1–2 and 1–3 mixing in both charged lepton and neutrino sectors leaving the 2–3 mixing angles as free parameters. We then restrict the lightest neutrino mass as well as the difference between 2–3 mixing angles in charged lepton and neutrino sectors from the requirement of producing correct leptonic mixing angles. We constrain the lightest neutrino mass to be around 0.002 eV and leptonic Dirac CP phase [Formula: see text] such that [Formula: see text]. We also construct the leptonic mass matrices in terms of 2–3 mixing angles and lightest neutrino mass and briefly comment on the possibility of realizing texture zeros in the neutrino mass matrix.


2016 ◽  
Vol 25 (4) ◽  
pp. 291
Author(s):  
Vo Van Vien ◽  
Hoang Ngoc Long ◽  
Phan Ngoc Thu

We show that the neutrino mass matrix of the Zee-Babu model isable to fit the recent data on neutrino masses and mixingwith non-zero $\theta_{13}$ in the inverted neutrino mass hierarchy. The results show that the Majorana  phases are equal to zero and the Dirac phase ($\de$) ispredicted to either $0$ or $\pi$, i. e, there is no CP violation in the Zee-Babu model at the two loop level. The effective mass governingneutrinoless double beta decay and the sum of neutrino masses areconsistent with the recent analysis.


2013 ◽  
Vol 2013 ◽  
pp. 1-35 ◽  
Author(s):  
Milind Diwan ◽  
Rob Edgecock ◽  
Takuya Hasegawa ◽  
Thomas Patzak ◽  
Masato Shiozawa ◽  
...  

We review the ongoing effort in the US, Japan, and Europe of the scientific community to study the location and the detector performance of the next-generation long-baseline neutrino facility. For many decades, research on the properties of neutrinos and the use of neutrinos to study the fundamental building blocks of matter has unveiled new, unexpected laws of nature. Results of neutrino experiments have triggered a tremendous amount of development in theory: theories beyond the standard model or at least extensions of it and development of the standard solar model and modeling of supernova explosions as well as the development of theories to explain the matter-antimatter asymmetry in the universe. Neutrino physics is one of the most dynamic and exciting fields of research in fundamental particle physics and astrophysics. The next-generation neutrino detector will address two aspects: fundamental properties of the neutrino like mass hierarchy, mixing angles, and the CP phase, and low-energy neutrino astronomy with solar, atmospheric, and supernova neutrinos. Such a new detector naturally allows for major improvements in the search for nucleon decay. A next-generation neutrino observatory needs a huge, megaton scale detector which in turn has to be installed in a new, international underground laboratory, capable of hosting such a huge detector.


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Sandhya Choubey ◽  
Dipyaman Pramanik

Abstract In presence of non standard interactions (NSI), the solar neutrino data is consistent with two solutions, one close to the standard LMA solution with sin2θ12 ≃ 0.31 and another with $$ {\sin}^2{\theta}_{12}^D\simeq 0.69\left(=1-{\sin}^2{\theta}_{12}\right) $$ sin 2 θ 12 D ≃ 0.69 = 1 − sin 2 θ 12 . The latter has been called the Dark LMA (DLMA) solution in the literature and essentially brings an octant degeneracy in the measurement of the mixing angle θ12. This θ12 octant degeneracy is hard to resolve via oscillations because of the existence of the so-called “generalised mass hierarchy degeneracy” of the neutrino mass matrix in presence of NSI. One might think that if the mass hierarchy is independently determined in a non-oscillation experiment such as neutrino-less double beta decay, one might be able to break the θ12 octant degeneracy. In this paper we study this in detail in the context of long-baseline experiments (Pμμ channel) as well as reactor experiments (Pee channel) and show that if we combine information from both long-baseline and reactor experiments we can find the correct octant and hence value of θ12. We elaborate the reasons for it and study the prospects of determining the θ12 octant using T2HK, DUNE and JUNO experiments. Of course, one would need information on the neutrino mass hierarchy as well.


2008 ◽  
Vol 23 (21) ◽  
pp. 3388-3394
Author(s):  
HISAKAZU MINAKATA

I discuss why and how powerful is the two-detector setting in neutrino oscillation experiments. I cover three concrete examples: (1) reactor θ13 experiments, (2) T2KK, Tokai-to-Kamioka-Korea two-detector complex for measuring CP violation, determining the neutrino mass hierarchy, and resolving the eight-fold parameter degeneracy, (3) two-detector setting in a neutrino factory at baselines 3000 km and 7000 km for detecting effects of non-standard interactions (NSI) of neutrinos.


Universe ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 41
Author(s):  
Antonio Palazzo

Several anomalies observed in short-baseline neutrino experiments suggest the existence of new light sterile neutrino species. In this review, we describe the potential role of long-baseline experiments in the searches of sterile neutrino properties and, in particular, the new CP-violation phases that appear in the enlarged 3 + 1 scheme. We also assess the impact of light sterile states on the discovery potential of long-baseline experiments of important targets such as the standard 3-flavor CP violation, the neutrino mass hierarchy, and the octant of θ 23 .


2013 ◽  
Vol 2013 ◽  
pp. 1-34 ◽  
Author(s):  
Soo-Bong Kim ◽  
Thierry Lasserre ◽  
Yifang Wang

We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very recently the most precise determination of the neutrino mixing angleθ13. This paper provides an overview of the upcoming experiments and of the projects under development, including the determination of the neutrino mass hierarchy and the possible use of neutrinos for society, for nonproliferation of nuclear materials, and geophysics.


2020 ◽  
Vol 493 (1) ◽  
pp. L81-L86 ◽  
Author(s):  
P Atri ◽  
J C A Miller-Jones ◽  
A Bahramian ◽  
R M Plotkin ◽  
A T Deller ◽  
...  

ABSTRACT Using the Very Long Baseline Array and the European Very Long Baseline Interferometry Network, we have made a precise measurement of the radio parallax of the black hole X-ray binary MAXI J1820+070, providing a model-independent distance to the source. Our parallax measurement of (0.348 ± 0.033) mas for MAXI J1820+070 translates to a distance of (2.96 ± 0.33) kpc. This distance implies that the source reached (15 ± 3) per cent of the Eddington luminosity at the peak of its outburst. Further, we use this distance to refine previous estimates of the jet inclination angle, jet velocity, and the mass of the black hole in MAXI J1820+070 to be (63 ± 3)°, (0.89 ± 0.09) c, and (9.2 ± 1.3) M⊙, respectively.


2001 ◽  
Vol 16 (29) ◽  
pp. 1881-1886
Author(s):  
MOHAN NARAYAN ◽  
S. UMA SANKAR

Recently it is advocated that high intensity and low energy (Eν~2 GeV ) neutrino beams should be built to probe the (13) mixing angle ϕ to a level of a few parts in 104. Experiments using such beams will have better signal-to-background ratio in searches for νμ→νe oscillations. We propose that such experiments can also determine the sign of Δ31 even if the beam consists of neutrinos only. By measuring the νμ→νe transitions in two different energy ranges, the effects due to propagation of neutrinos through earth's crust can be isolated and the sign of Δ31 can be determined. If the sensitivity of an experiment to ϕ is ε, then the same experiment is automatically sensitive to matter effects and the sign of Δ31 for values of ϕ≥2ε.


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